JP3353571B2 - Earth shape measurement device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the shape of the earth's surface, which is usually approximated to a spheroid, and quantifying the shape as a coordinate position on a single coordinate system. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an earth shape measuring device that quantifies a degree, a distance between continents, and a shape such as undulations of the earth surface to generate topographical information of the entire earth surface.

[0002]

2. Description of the Related Art FIG. 14 is a diagram showing a satellite triangulation device which is one of the conventional earth shape measuring devices. In FIG. 14, reference numeral 12 denotes the earth, 34 denotes a geodetic satellite, 35a denotes a first reference point,
35b is a second reference point, 36 is a camera, and 37 is a measurement point.

Next, the principle will be described with reference to FIG. FIG. 15 is a principle diagram of the satellite triangulation, in which 12 is the earth, 38 is the orbit of the geodetic satellite, 39 is a straight line whose distance is known, 40 is a straight line whose distance is unknown, 41 is the position of the geodetic satellite at time t1. s1, 42 are the positions s2, 35a of the geodetic satellite at time t2, the first reference point A, 35b is the second reference point B, and 37 is the measurement point X. Since the geodetic satellite 34 is dark but reflects sunlight, the camera can catch the geodetic satellite 34. A timing device (not shown) can determine the right ascension and declination of the geodetic satellite 34 at the observation time by comparing with the position of the background star. A point whose position coordinates are known, that is, a first reference point A35
When determining the position of the measurement point X37 from the position a and the second reference point B35b, in the figure, the geodetic satellite 34 performs simultaneous observation at the position of S1 at the first reference point A35a, the second reference point B35b, and the measurement point X37. By doing, AS1, BS
1, the direction of XS1 is determined. Since the length of AB is known, the triangle ABS1 is determined. Next, the geodetic satellite 34 is S2
If the simultaneous observation is performed again at the position of
Is geometrically determined as the intersection of XS1 and XS2, so that the position coordinates of the measurement point X37 can be known. By repeating this principle, the earth shape is measured by measuring the relative positions of various parts of the earth's surface.

FIG. 16 is a diagram showing an aerial triangulation device which is one of other conventional earth shape measuring devices. In the figure, 43 is an aircraft, 36 is a camera, 31 is an anti-aircraft sign, 44
Is the field of view of the camera, and 12 is the earth. In the figure, an aerial photograph of the ground surface is photographed by a camera 36 mounted on an aircraft 43, and an altitude calculation is performed by stereoscopically viewing overlapping portions of a plurality of aerial photographs of the same area taken from different positions. In the altitude calculation, since only the relative height difference within the visual field range of the photograph is known, the anti-aircraft sign 31 whose position coordinates are known in advance is set on the ground, and the visual field range 4 of the camera that captures the aerial photograph.
The image of the anti-aircraft sign 31 is taken at 4 and used as a reference for calculating the altitude.

[0005]

Quantitatively grasping the Earth's surface shape such as a flat elliptical shape deformed like a pear is an important theme useful for elucidating many phenomena of geophysics. However, it has been an issue to measure the surface shape of the earth in a single coordinate system in detail. On the other hand, in the conventional earth shape measurement device, when measuring with a measuring device on the ground, the position of the point where the measuring device is installed can be measured with high accuracy, but other locations can not be measured, The undulation of the earth's surface could not be quantified as three-dimensional information. In addition, since the required number of facilities and equipment increases as the number of measurement points increases, there has been a problem that enormous cost and labor are required to acquire data on the entire surface of the earth. In addition, it was difficult to obtain a data volume covering the earth's surface because it was difficult to secure a place to install a measuring instrument. In addition, there is a problem that an unmeasurable region remains in polar regions or undeveloped regions because measurement equipment cannot be introduced.

In conventional triangulation, in which the position of another point is measured as a reference between two points whose relative distance on the ground is known, the distance cannot be measured as long as the ocean is sandwiched between the two points. And the distance between two points between the continent and the island nation cannot be measured, and the relative position between the continents and the island nation cannot be determined.

In the measurement method based on the vertical direction, there is a problem that the vertical direction itself has anisotropy depending on the location due to the bias of gravity due to the existence of the ore deposit and the like, so that it is not a stable standard. Was.

In the method of analyzing elevation by stereoscopic vision using the parallax of image data taken from different positions, such as aerial triangulation, only the relative elevation difference within one screen is calculated. If there is no anti-aircraft sign whose position and altitude are known in the screen, there is a problem that the absolute coordinates cannot be known.

When the longitude is measured using the earth rotation as a reference for determining the time, there has been a problem that the absolute time accuracy becomes insufficient due to the fluctuation of the rotation speed accompanying the movement of the earth rotation axis. Further, since the satellite flies at a speed of several kilometers per second, there is a problem that if the time accuracy is poor, the position accuracy cannot be increased.

[0010] Further, a plurality of ellipsoids in which the elliptical shape of the earth is formulated have been proposed, and the ellipsoids used in each country are different, and there is a difference of up to 1 km in a long radius. Even if it is desired, there is a problem that a reference for alignment in a single coordinate system cannot be obtained.

When performing aerial triangulation by stereoscopically viewing image data acquired at two points in the air by an aircraft or a satellite, the distance between the two points at which the images were acquired must be accurately determined because the position coordinates fluctuate every moment. Since it is difficult to grasp, there is a problem that a measurement error increases. Even when measuring position coordinates using a navigation satellite, there has been a problem that the measurement accuracy cannot be improved only by measuring the position of one satellite.

When performing aerial triangulation by stereoscopically viewing image data acquired at two points in the air by a satellite, it is necessary to accurately grasp the angle of the line of sight. In the method of capturing, there is a problem that it is not always possible to grasp the angle with high accuracy because errors occur due to satellite movement and there are blind spots where stars are not visible.
Further, although the blind area is not generated in the method using the gyro, there is a problem that there is no gyro with sufficiently high accuracy.

In the case of measurement from an aircraft or a satellite, there is a problem that there is no means for performing a correction process later because related information does not remain even if the aircraft or the satellite shakes or changes in attitude. Especially when acquiring images using line sensors,
Since the position and attitude information of the satellite at all imaging timings is not known, there is a problem that if the attitude of the satellite fluctuates during imaging, the geometric distortion of the image cannot be corrected and becomes an unresolved error factor.

The equator from the tropics to the subtropics and the polar regions near the North Pole and the South Pole are important areas for grasping the shape of the earth. Conventionally, an apparatus for stereoscopically viewing satellite image data uses an optical sensor. Therefore, there was a problem that data that could be used practically could not be obtained from cloudy areas or high latitudes with little sunlight reflection to polar regions.

In order to calculate the absolute value of the altitude based on the parallax of the image data, the effect of the shaking or position measurement error of the onboard satellite or aircraft and the angle error in the line-of-sight direction is large. There was a problem that I could not stand.

Therefore, there has been a long-awaited need for an earth shape measuring apparatus capable of quantifying the earth surface shape as high-precision three-dimensional information on a single coordinate system.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an earth shape measuring apparatus capable of quantifying the entire earth surface as three-dimensional information by using earth surface image data viewed from space. I will provide a.

Further, there is provided an earth shape measuring apparatus capable of generating a topographic map in which maps of each country are matched with accuracy of about several tens of meters on a single coordinate system.

[0019] Even if there is no equipment on the ground, measurement is possible only with image data viewed from space, so that data in areas where human activities cannot be reached can be measured.

Further, there is provided an earth shape measuring apparatus capable of measuring the coordinates of the earth surface position by a single coordinate system operating a navigation satellite.

Since the time is managed by using atomic clocks having high frequency stability and mutually adjusted, an earth shape measuring apparatus capable of measuring with a common time reference regardless of time and place is provided.

Further, the present invention provides an earth shape measuring apparatus which is not affected by a local gravity deviation because an altitude is analyzed using only geometric features.

Since the earth surface is measured by the principle of triangulation from two points whose position coordinates are known, an earth shape measuring device capable of measuring the absolute coordinates of the ground surface is provided.

In the position measurement using the navigation satellite, the satellite 1 is used.
Measuring accuracy cannot be improved only by measuring the position of the platform, but the relative distance between two points can be measured with high precision, and the distance between two satellites in orbit can be grasped with high precision. Highly accurate aerial triangulation provides an earth shape measurement device.

Since the angle of the line of sight is measured with reference to an observation satellite flying in the same orbit or an adjacent orbit while maintaining the relative distance, an earth shape measuring apparatus capable of performing aerial triangulation with high measurement accuracy is provided. I do.

Further, the present invention provides an earth shape measuring device with sufficiently high accuracy on a global scale by improving the measurement accuracy of time, position, and angle, and taking measures for correcting the values.

Since the image data has a time history of the imaging timing and the satellite position and the line-of-sight information at the imaging time can be verified, an earth shape measuring apparatus capable of correcting the attitude change is provided.

According to the synthetic aperture radar using microwaves, it is possible to acquire an image of an area covered with clouds or without sunlight irradiation. To provide an earth shape measuring device capable of effectively acquiring the information.

[0029]

Embodiment 1 of the present invention
Is an imager that directs the Earth's surface,
It consists of an observation satellite equipped with a clock, a signal processing circuit, an angle detector, and a navigation satellite signal receiver, an image database, and a navigation satellite.

Also, there are two observation satellites that fly in the same orbit while maintaining the same relative distance as the orbit altitude while imaging the same location on the ground surface. The sets are matched, and the position and altitude of the earth's surface are analyzed using satellite position coordinates, gaze direction angles, and parallax.

Time is managed between a navigation satellite, an observation satellite, and a ground station using an atomic clock having high time stability, and image data, satellite position data, and line-of-sight angle data are time-managed with each other.

Also, the observation satellite is provided with a navigation satellite signal receiver, and the position on the coordinate system adopted by the navigation satellite is clearly measured, and the relative distance between the two satellites is accurately determined by using the difference between the data. Is what you want.

Each of the two observation satellites has a light source,
The angle detectors of the respective observation satellites detect light emitted from the light source of the other observation satellite to detect the relative angle between the line of sight of the imager and the direction of the light source.

An image database is provided on the ground, and image data, position data and angle data of observation satellites are recorded together with time information.

An earth shape measuring apparatus according to a second embodiment of the present invention is an observation satellite equipped with an image pickup device, a clock, a signal processing circuit, an angle detector, a navigation satellite signal receiver, an image database, and a navigation device pointing at the earth's surface. Composed of satellites,
Although it has the same two observation satellites that fly in the same orbit while maintaining the same relative distance as the orbit altitude while imaging the same place on the ground, it is the same as in the first embodiment. The observation satellites each have a mirror ball, and the other observation satellite has an angle detector that detects the sun reflected light emitted by the mirror ball and detects the line of sight of the imaging device, the direction of the mirror ball, and the relative angle. is there.

An earth shape measuring apparatus according to a third embodiment of the present invention includes an observation satellite having an image pickup device, a clock, a signal processing circuit, an angle detector, a navigation satellite signal receiver, an image database, and the like. And the navigation satellites in the same manner as in the first embodiment, except that the observation satellites include three observation satellites flying in adjacent orbits while imaging the same place on the surface of the earth, and The observation satellite flies while maintaining a relative distance between the other two observation satellites that is approximately equal to the orbital altitude, and is equipped with a mirror ball or a light source, and is emitted by the other two observation satellite mirror balls. The apparatus includes an angle detector that detects reflected light or light emitted from a light source to detect a relative angle between a line of sight of the imaging device and a direction of a mirror ball.

An earth shape measuring apparatus according to a fourth embodiment of the present invention is an observation satellite equipped with an image pickup device, a clock, a signal processing circuit, an angle detector, a navigation satellite signal receiver, an image database, and a navigation device which point at the earth's surface. It is the same as the first embodiment except that it has three or more observation satellites that fly in the same orbit while imaging the same place on the surface of the earth, and each observation satellite The satellite flies while maintaining a relative distance approximately equal to the orbital altitude between observation satellites that fly back and forth and has a mirror ball or light source, and the sun reflected light or light source emitted by the mirror balls of the front and rear observation satellites Is provided with an angle detector for detecting the light emitted from the camera and detecting the relative angle between the direction of the line of sight of the imaging device and the direction of the mirror ball.

A terrestrial shape measuring apparatus according to Embodiment 5 of the present invention uses an imaging radar as an imager, and one imaging radar includes a transmitter.
All imaging radars receive the ground reflected waves of the signal emitted from the transmitter and generate radar images.

The earth shape measuring apparatus according to the sixth embodiment of the present invention uses an imaging radar as an imaging device, one imaging radar includes a transmitter, and another imaging radar includes the transmitter. And a transmitter having another frequency or polarization characteristic, and all imaging radars receive the ground reflected waves of the signals emitted by the two transmitters to generate a radar image.

In the earth shape measuring apparatus according to the seventh embodiment of the present invention, the time of all the imaging timings is added to the image data in the signal processing section, transmitted to the ground, and recorded in the image database together with the image data. is there.

An earth shape measuring apparatus according to an eighth embodiment of the present invention has an anti-aircraft sign whose position coordinates have been measured in advance by a navigation satellite or a geodetic satellite on the surface of the earth.

[0042]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. FIG. 1 is a block diagram showing a first embodiment of the present invention. In FIG.
, 1b is a second image pickup device pointing to the same place as the first image pickup device 1a on the ground, 2a is a first timepiece, 2b is a second timepiece adjusted to the first timepiece 2a, 3 is a navigation satellite signal receiver, 4a is a first angle detector, 4b is a second angle detector, 5 is a signal processing circuit, and 6a is a first imager of the earth image taken by the first imager 1a. Observation satellite, 6b
A second observation satellite 7 which flies in the same orbit as the first observation satellite 6a while maintaining a relative distance approximately equal to the orbit altitude;
Is an image database for recording image data and position data and angle data of observation satellites together with time information.
Is a first light source that emits light from the observation satellite 6a to the observation satellite 6b, 8b is a second light source that emits light from the second observation satellite 6b to the first observation satellite 6a, and 10 is a ground station. , 11 are navigation satellites, 12 is the earth, and the first observation satellite 6a is a first imager 1a, a first clock 2a, a navigation satellite signal receiver 3, a first angle detector 4a, a signal processor. Circuit 5, a first light source 8a, and a second observation satellite 6
b includes a second imaging device 1b, a second clock 2b, a navigation satellite signal receiver 3, a second angle detector 4b, a signal processing circuit 5, and a second light source 8b.

In the figure, among the first observation satellites 6a, the first imaging device 1a images the surface of the earth 12 in accordance with the imaging timing signal generated by the first clock 2a, and converts the image data into a signal processing circuit. Send to 5. Further, the first clock 2 a outputs the time information at which the imaging timing signal is generated to the signal processing circuit 5.
Send to The navigation satellite signal receiver 3 receives the signal of the navigation satellite 11 according to the timing signal generated by the first clock 2a, and transmits the satellite position information at that time to the signal processing circuit 5. Further, the first observation satellite 6a has an orbit altitude of 7, for example.
When flying at about 00 km, the second observation satellite 6 flying in the same orbit while maintaining a relative distance of about 700 km
The light source 8a detectable from b is set in the first observation satellite 6a. Therefore, the first angle detector 4a is connected to the first timepiece 2a.
The second observation satellite 6b according to the timing signal
, The light emitted from the second light source 8b mounted on the first imaging device 1a is measured, and the angle between the direction of the light source and the line of sight of the first image pickup device 1a is measured, and the angle data is transmitted to the signal processing circuit 5. At this time, if the line-of-sight direction of the first imaging device 1a is fixed with respect to the first observation satellite 6a, the angle data indicates the attitude change angle of the observation satellite 6a, and the first imaging device 1a If the camera has the direction changing function, the angle data indicates the sum of the attitude change angle of the observation satellite 6a and the line-of-sight direction changing angle. Further, by using a star sensor or using a telescope with a two-dimensional array detector as the first angle detector 4a, sufficiently high-accuracy angle management becomes possible. Note that the angle around the linear axis connecting the first observation satellite 6a and the second observation satellite 6b is measured by another angle detector such as an earth sensor for observing the earth direction or a gyro.

The signal processing circuit 5 adds additional information such as identification information to the received time information, image data, position data, and angle data, and then processes the received data into a format that can be transmitted to the ground, via a transmitter (not shown). To the ground station 10. Needless to say, the data can be transmitted via a data relay satellite (not shown). Note that the first timepiece 2a
There are three types of timing signals generated in the following: imaging timing, position information acquisition timing, and angle information acquisition timing. If the respective times are accurately recorded, they need not be synchronized with each other. It is recorded in the signal processing circuit 5 together with the corresponding image data or position data or angle data. The imaging timing is set in the first timepiece 2a based on the timing of starting the image acquisition and the interval at which the imaging is repeated. Further, the position information acquisition timing and the angle information acquisition timing are set in the first clock 2a at a frequency sufficient to satisfy the position accuracy and the angle accuracy required for analyzing the earth surface position coordinates.

Similarly, among the second observation satellites 6b, the time information of the second clock 2b, the image data of the second imaging device 1b, the position data, the angle data, and the incidental information are transmitted to the ground. The operation related to the angle detector 4 is the same as that of the first observation satellite 6a, and the second angle detector 4b is mounted on the first observation satellite 6a according to the timing signal generated by the second clock 2b. The light emitted from the first light source 8a is detected, the angle between the direction of the light source and the line of sight of the second imaging device 1b is measured, and the angle data is transmitted to the signal processing circuit 5.

Next, the ground station 10 receives the information transmitted by the receiver (not shown) and records it in the image database. In the image database 7, image data, position data,
Records and manages angle data and incidental information. Since the angle formed by the line of sight and the vertical direction of the second imaging device 1b is different from that of the first imaging device 1a, the image data obtained by the first imaging device 1a and the terrestrial image obtained by the second imaging device 1b are different. The corresponding location in the image data of the same location is matched, the altitude of the earth surface is analyzed using the parallax of both images, and the result is digitized as the earth surface position coordinate. At this time, the relative distance between the two observation satellites is obtained by calculating the difference between the position data of the first observation satellite 6a and the position data of the second observation satellite 6b. Also, a straight line connecting the two observation satellites and the first imaging device 1a
The angle between the line of sight and the line of sight of the second imaging device 1b is determined by the angle data of the first angle detector 6a.
Since it is known from the angle data b, the position coordinates of the ground surface can be calculated when the coordinate system of the navigation satellite is used as the reference coordinates.
As for the angle around the linear axis connecting the first observation satellite 6a and the second observation satellite 6b, the direction of the earth measured by a separate gyro or earth sensor is known, and when matching image data for stereoscopic viewing. Since the relative error can be removed, the error in the elevation analysis can be made sufficiently small. Alternatively, two light sources may be separately mounted on one observation satellite, and the relative angle may be measured by identifying the two points from a distance.

Next, the principle will be described with reference to FIG.
FIG. 2 is a schematic diagram of the shape of the earth and the satellite orbit in Embodiment 1 of the present invention. In the figure, 6a is a first observation satellite, 6b is a second observation satellite, 11a is a first navigation satellite,
11b is a second navigation satellite, 11c is a third navigation satellite, 1
1d is the fourth navigation satellite, 12 is the earth, 13 is the spheroid, 14a is the line of sight of the first imager, 14b is the line of sight of the second imager, 15 is the orbit of the observation satellite, and 16 is the orbit of the navigation satellite. Orbit. In the present invention, since the shape of the earth 12 is measured without using the spheroid 13 as a reference for measuring the earth shape and without using the earth gravity as a reference for measuring the earth shape, the shape of the earth is measured by triangulation from a space outside the earth. I do. The orbits of observation satellites and navigation satellites are determined by the influence of the earth's gravity. However, since navigation satellites fly at a high altitude of about 2000 km, the influence of gravity bias is originally small, and for example, global positioning in the United States In a device such as a device that has been sufficiently subjected to the effect correction processing, the position coordinates can be determined without being affected by the change in the earth's gravity. Therefore, it is possible to determine the position coordinates by measuring the shape of the earth on a single coordinate system using a geodetic coordinate system called World Geodetic System 84 adopted in a global positioning device, for example. The position coordinates of the first observation satellite 6a and the second observation satellite 6b are determined on the coordinate system adopted by the navigation satellite 11 based on the signals of the plurality of navigation satellites 11.

Next, a method for accurately determining the position of an observation satellite using a navigation satellite will be described. Since the position of the navigation satellite 11 is accurately determined, three different navigation satellites 11a, 11a,
It is only necessary to receive the navigation signals from 11b and 11c and determine the distance. Further, if the signals from the navigation satellites 11d are received to eliminate the influence of the error due to the delay of the signal propagation time until the signals from the navigation satellites are received, the orbit of each navigation satellite is known, so that the The relative position is known, and the position accuracy is improved. Also, when measuring the position of a single observation satellite, the measurement error is large due to the influence of the ionosphere while the signal from the navigation satellite is propagating, but the two observation satellites 6 flying in the same or adjacent orbits. When measuring the position of the satellite, most of the error factors are generated jointly between the two satellites. Therefore, if the amount of difference between the position data is determined, the relative distance between the two observation satellites is highly accurate because the error component is eliminated. Can be measured.

Assuming that the angle between the line connecting the two observation satellites and the line of sight of the first imaging device 1a is θ1, θ1 is measured by the angle data of the first angle detector 6a.
Assuming that the angle between the line connecting the two observation satellites and the line of sight of the second imaging device 1b is θ2, since θ2 is measured by the angle data of the second angle detector 6b, triangulation from space It is possible to calculate the position coordinates of the ground surface when the coordinate system of the navigation satellite is used as the reference coordinates. Since the position coordinates of the satellite change every moment along the orbital direction, it is indispensable to manage the time using a highly accurate clock whose time has been set. Therefore, sufficiently accurate time management is performed by using an atomic clock such as a quartz clock as a reference oscillation source.

Next, the principle of altitude extraction by image stereoscopic vision will be described with reference to FIG. FIG. 3 is a diagram showing the principle of altitude extraction based on the parallax of stereoscopic vision when an optical sensor using a line sensor is used as an imaging device. In the figure, 12 is the earth, 14a is the line of sight of the first imager, 14b is the line of sight of the second imager, 17a is the position A of the first observation satellite,
17b is the position B of the second observation satellite, 18 is the intersection C of the line of sight, 19 is the observation target point D on the ground surface on C, 20a is the parallel line of the line of sight of the first imager passing through D, and 20b is D. 2nd passing
21a is the position of D in the image of the first image pickup device, and 21b is the position of D in the image of the second image pickup device.

The position A17a of the first observation satellite and the position B71b of the second observation satellite are determined using navigation satellites, and the angles θ1 and θ2 are determined using an angle detector. So the first
The intersection C18 of the two lines of sight of the line of sight 14a of the imager and the line of sight 14b of the second imager is determined. Therefore, when considered on a plane including the points A, B, and C, the coordinate position of C is determined. A
The distance H between B and point C is also determined. If the altitude difference h between the elevation of the observation target point D and the point C on the ground surface is 0, the point D matches the intersection C of the line of sight 14a of the first imager and the line of sight 14b of the second imager, The position of point D projected on the image is point A
When the actual h is not 0, the position of the point D projected on the image is parallel to the line of sight 20a passing through D and the line of sight of the first image pickup device. Through the parallel line 20b with the line of sight of the imager, the position E21a of D in the image of the first imager and the position D21 in the image of the second imager, respectively.
Is captured at the position F21b. AE in the image
The distance x1 and the distance x2 between the AF points are parallaxes equivalent to the ground equivalent distance, and the altitude h can be calculated as h = x1 / tan θ1 + x2 / tan θ2.

In the case of an optical sensor using a line sensor, since the imaging location changes in accordance with the progress of the satellite while keeping the direction of the field of view constant, the altitude h is calculated from the distances AE and AF. AC in the figure
The altitude can be calculated from the angle difference between the angle and AD. Note that, in FIG. 3, the plane geometry has been described. However, in the three-dimensional geometry, the elevation can be extracted by stereoscopic vision in the same way.
With the satellite position data and the line-of-sight angle data as described above, the position coordinates of the point C18, which is the reference for the altitude calculation, can be determined, and the parallax of the place where the point D is actually captured in a series of images is determined. The feature of this method is that the altitude of D is obtained based on this.

Next, a specific example of the image database will be described with reference to FIG. FIG. 4 is a diagram showing an example of the structure of an image database. In FIG.
2 is image data, 23 is an image header, 27 is each pixel data, 45 is an image data block, 46 is a position data block, 47 is an angle data block, 28 is a header, 30
Indicates satellite position data, and 33 indicates angle data.

The image database 7 has an image data block 45, a position data block 46, and an angle data block 47, and records data received from observation satellites. The image data 22 is composed of an image header 23, a header 28, and each pixel data 27, and indicates an information group regarding a continuous image. Since the header 28 includes time information, the pixel data 27 is associated with the position data 30 and the angle data 33 by referring to the header 28. At this time, the acquisition frequency of the position data and the angle data can be arbitrarily set according to the vibration condition of the observation satellite and the required level of the altitude analysis accuracy. Therefore, the image data always corresponds to the position data and the angle data one-to-one via the header 28. No need.

Since a method for accurately measuring the relative distance between two observation satellites has already been described, an example of a method for accurately determining the absolute position coordinates of the observation satellite in the reference coordinate system using the navigation satellite will be described below. 5 will be described. FIG. 5 is a diagram showing an example of a method for improving the position accuracy by using a plurality of navigation satellite data, in which 6 is an observation satellite, 11a.
Denotes a first navigation satellite, 11b denotes a second navigation satellite, 11c denotes a third navigation satellite, 11d denotes a fourth navigation satellite, 10 denotes a ground station, and 12 denotes the earth. As described with reference to FIG. 2, four different navigation satellites 11a, 11b, 1
Signals from 1c and 11d are received. Further, the position coordinates of the ground station 10 can be accurately measured in advance in order to eliminate the influence of the ionosphere while the signal from the navigation satellite is propagating. The positions of 10 are assigned to the navigation satellites 11a, 11b, 11c,
If the position coordinates of the observation satellite 6 are obtained from the difference with reference to the position coordinates of the ground station,
The position of the observation satellite in the reference coordinate system can be accurately measured. The position coordinates of the ground station 10 can be accurately measured by performing measurement using a geodetic satellite.

Embodiment 2 FIG. 6 is a block diagram showing a second embodiment of the present invention. In the drawing, reference numeral 1a denotes a first image pickup device directed to the earth surface, and 1b denotes a second image pickup device directed to the same ground surface as the first image pickup device 1a. , A first clock, 2b a second clock synchronized with the first clock 2a, 3 a navigation satellite signal receiver, 4a a first angle detector, 4b a second clock Angle detector, 5 is a signal processing circuit, 6a
Is a first observation satellite that images the earth's surface with the first imaging device 1a, and 6b is a second observation satellite that flies in the same orbit as the first observation satellite 6a while maintaining a relative distance similar to the orbit altitude. An observation satellite, 7 is an image database that records image data and position data and angle data of the observation satellite together with time information, 9a is a first mirror ball attached to the surface of the first observation satellite 6a opposite to the earth-facing surface, 8b is a second mirror ball mounted on the surface of the second observation satellite 6b opposite to the earth-facing surface, 10 is a ground station, 11 is a navigation satellite, 12 is the earth, and the first observation satellite 6a is a second 1 imager 1a, 1st
Clock 2a, a navigation satellite signal receiver 3, a first angle detector 4a, a signal processing circuit 5, a first mirror ball 9a, and a second observation satellite 6b has a second imager 1b, 2
, A navigation satellite signal receiver 3, a second angle detector 4b, a signal processing circuit 5, and a second mirror ball 9b.

In the figure, when an optical image pickup device for detecting the reflected light of the sun's surface is used as the image pickup device 1, when the observation satellite 6 picks up an image, sunlight is always emitted from the surface opposite to the earth-facing surface. . Therefore, when a mirror ball with mirror pieces spread over the surface of the sphere is installed, sunlight is reflected in all directions by the mirror ball. For example, on the surface opposite to the earth-facing surface of the first observation satellite 6a flying at an orbit altitude of about 700 km. If the first mirror ball 9a is set, it is possible to detect the sun reflected light from the second observation satellite 6b flying in the same or adjacent orbit while maintaining a relative distance of about 700 km. Therefore, the first angle detector 4a detects the sun reflected light emitted from the second mirror ball 9b mounted on the second observation satellite 6b according to the timing signal generated by the first clock 2a, and Is measured and the angle between the line of sight and the line of sight of the first imaging device 1a is measured, and the angle data is transmitted to the signal processing circuit 5. At this time, if the line-of-sight direction of the first imaging device 1a is fixed with respect to the first observation satellite 6a, the angle data indicates the attitude variation angle of the observation satellite 6a, and the first imaging device 1a When the gaze direction changing function is provided, the angle data indicates the sum of the attitude change angle of the observation satellite 6a and the gaze direction change angle. Further, by using a star sensor or using a telescope with a two-dimensional array detector as the first angle detector 4a, sufficiently high-accuracy angle management becomes possible.

Similarly, in the second observation satellite 6b, the second angle detector 4b is mounted on the first observation satellite 6a according to the timing signal generated by the second clock 2b.
Of the mirror ball 9b, and measures the angle between the direction of the mirror ball 9a and the line of sight of the second imaging device 1b, and transmits the angle data to the signal processing circuit 5. Embodiment 1 except for the operation related to the angle detector 4
When the altitude extraction processing is performed on the ground, the relative distance between the two observation satellites is calculated by calculating the difference between the position data of the first observation satellite 6a and the position data of the second observation satellite 6b. The determination is the same as in the first embodiment.

Embodiment 3 FIG. 7 is a block diagram showing a third embodiment of the present invention, in which 1a is a first image pickup device pointing at the earth surface, and 1b is a second image pickup pointing at the same place on the ground as the first image pickup device 1a. Imager, 1c is the first
A third imaging device pointing at the same place on the ground surface as the imaging device 1a of
2a is a first clock, 2b is a second clock whose time is adjusted to the first clock 2a, 2c is a third clock which is adjusted to the first clock 2a, 3 is a navigation satellite signal receiver, 4a
Is a first angle detector, 4b is a second angle detector, 4c is a third angle detector, 5 is a signal processing circuit, and 6a is the first angle detector.
First observation satellite that images the earth's surface with the imager 1a
b is a second observation satellite that flies in the same orbit as the first observation satellite 6a while maintaining a relative distance equivalent to the orbit altitude,
Reference numeral 6c denotes a third observation satellite having the same orbit altitude as the first observation satellite 6a and flying in an adjacent orbit at another orbit altitude, and 7 records image data and position data and angle data of the observation satellite together with time information. An image database, 9a, is a first mirror ball mounted on the surface of the first observation satellite 6a opposite to the earth-facing surface, and 8b is a second mirror ball mounted on the surface of the second observation satellite 6b, opposite to the earth-facing surface. Mirror ball, 8c is the second
Of the second observation satellite 6c mounted on the surface opposite to the earth-facing surface
Mirror ball, 10 is a ground station, 11 is a navigation satellite, 12
Is the earth, and the first observation satellite 6a is a first imager 1a, a first clock 2a, a navigation satellite signal receiver 3, a first angle detector 4a, a signal processing circuit 5, a first mirror. The ball 9a is mounted, and the second observation satellite 6b includes a second imaging device 1b, a second clock 2b, a navigation satellite signal receiver 3, a second angle detector 4b, a signal processing circuit 5, and a second A mirror ball 9b is mounted, and the third observation satellite 6c includes a third imaging device 1c, a third clock 2c, a navigation satellite signal receiver 3, a third angle detector 4c, a signal processing circuit 5, a third Mirror ball 9c.

When the first observation satellite 6a flies at an orbit altitude of, for example, about 700 km, the second observation satellite 6b and the third observation satellite 6c similarly flies at an orbit altitude of about 700 km, and The satellite 6a and the second observation satellite 6b fly while maintaining a relative distance of about 700 km, and the third observation satellite 6c has a relative distance of about 700 km with both the first observation satellite 6a and the second observation satellite 6b. Fly while maintaining. Therefore, the three observation satellites fly in the same orbit altitude while maintaining the triangular arrangement. At this time, it is necessary to match the orbit altitude in order to make the orbit period the same, but since the triangular shape does not necessarily have to be an equilateral triangle, the first
The observation satellite 6a and the second observation satellite 6b may fly in different adjacent orbits. However, three vehicles must not be connected to the same track.

Since the sun reflected light from the mirror ball 9 can be detected from another observation satellite 6 as in the second embodiment, the first angle detector 4a responds to the timing signal generated by the first clock 2a. The second mounted on the second observation satellite 6b
Of the mirror ball 9b and the sun reflected light of the third mirror ball 9c mounted on the third observation satellite 6c, respectively, to detect the direction of the mirror ball 9b and the line of sight of the first imaging device 1a. The angle between the direction and the angle between the direction of the mirror ball 9c and the line of sight of the first imaging device 1a is measured, and each angle data is transmitted to the signal processing circuit 5. Similarly, in the second observation satellite 6b, the second angle detector 4b includes the first angle detector 4b mounted on the first observation satellite 6a.
Reflected light of the mirror ball 9b and the third observation satellite 6c
, Respectively, and detects the sun reflected light of the third mirror ball 9c mounted thereon, and transmits angle data to the signal processing circuit 5.
The same applies to the third observation satellite 6c. The angle data is transmitted to the ground and recorded in an image database.

When performing the altitude extraction processing on the ground, the position data of the first observation satellite 6a and the second observation satellite 6b
In the same way as calculating the difference between the position data of the first and second observation satellites 6a and 6b in the same manner as calculating the relative distance between the first observation satellite 6a and the second observation satellite 6c. , And the relative distance between the second observation satellite 6b and the third observation satellite 6c are also obtained by calculating the respective positional data difference amounts. Further, when performing the altitude extraction processing on the ground, the relative positions and the angles of the line of sight of the three observation satellites that have acquired the images are respectively determined, so that the pair of the first imaging device 1a and the second imaging device 1b is set. Stereoscopic vision, stereoscopic vision of a set of a first imaging device 1a and a third imaging device 1c, a third imaging device 1c and a second imaging device 1
The earth surface position coordinate analysis is performed for a total of three pairs of the stereoscopic views of the set b.

Since the obtained three position coordinate data are data obtained by stereoscopic viewing from different directions, even if there is peculiar data including a large error, the peculiar data is obtained by cross-checking each other. It can be specified and removed. Further, even if there is a terrain that is shaded by a high mountain when viewed from a specific direction, the data can be interpolated by stereoscopic data from another direction, so that the credibility of the data increases. The operation of the equipment provided by the third observation satellite 6c is the same as the operation of the equipment provided by the second observation satellite 6b, and is the same as that of the first embodiment except for the operation relating to the angle detector 4 and ground processing. It is. Although the example using the mirror ball 9 has been described here, it goes without saying that the same operation can be performed even when the light source 8 is used.

Embodiment 4 FIG. 8 is a block diagram showing a fourth embodiment of the present invention. In the drawing, reference numeral 1a denotes a first image pickup device pointing to the earth surface, and 1b denotes a second image pickup device pointing to the same ground surface as the first image pickup device 1a. Imager, 1c is the first
A third imaging device pointing at the same place on the ground surface as the imaging device 1a of
2a is a first clock, 2b is a second clock whose time is adjusted to the first clock 2a, 2c is a third clock which is adjusted to the first clock 2a, 3 is a navigation satellite signal receiver, 4a
Is a first angle detector, 4b is a second angle detector, 4c is a third angle detector, 5 is a signal processing circuit, and 6a is the first angle detector.
First observation satellite that images the earth's surface with the imager 1a
b is a second observation satellite that flies backward in the same orbit as the first observation satellite 6a while maintaining a relative distance similar to the orbit altitude, and 6c is in the same orbit as the second observation satellite 6a in orbit altitude. A third observation satellite that flies backward while maintaining a relative distance similar to that of the first observation satellite, 7 is an image database that records image data and position data and angle data of the observation satellite together with time information, and 9a is a first observation satellite 6a A first mirror ball mounted on the surface opposite to the earth-facing surface of the second observation satellite 6b, a second mirror ball mounted on the surface opposite to the earth-facing surface of the second observation satellite 6b, and 8c is a second observation satellite 6c A second mirror ball mounted on the opposite side of the earth-facing surface of
11 is a navigation satellite, 12 is the earth, and the first observation satellite 6a is a first imaging device 1a, a first clock 2a, a navigation satellite signal receiver 3, a first angle detector 4a, a signal processing circuit. 5, a first mirror ball 9a is mounted, and a second observation satellite 6b is a second imager 1b, a second clock 2b, a navigation satellite signal receiver 3, a second angle detector 4b, a signal processor. A circuit 5 and a second mirror ball 9b are mounted, and a third observation satellite 6c includes a third imaging device 1c, a third clock 2c, a navigation satellite signal receiver 3, a third angle detector 4c, a signal The processing circuit 5 and the third mirror ball 9c are mounted.

When the first observation satellite 6a flies at an orbit altitude of, for example, about 700 km, the second observation satellite 6b and the third observation satellite 6c similarly fly at an orbit altitude of about 700 km, and The satellite 6b and the first observation satellite 6a 7
The third observation satellite 6c flies at a distance of 00 km and further 700 km behind the second observation satellite 6b while maintaining a relative distance. Accordingly, the three observation satellites fly in the same orbit. At this time, it is necessary to match the orbit altitude to make the orbit period the same, but the relative distance does not have to be exactly equal to the orbit altitude.
m, the relative distance may be set to about 350 km.

As in the second embodiment, since the sun reflected light from the mirror ball 9 can be detected from another observation satellite 6, the first angle detector 4a responds to the timing signal generated by the first clock 2a. The second mounted on the second observation satellite 6b
Of the mirror ball 9b, the angle between the direction of the mirror ball 9b and the line of sight of the first imaging device 1a is measured, and the angle data is transmitted to the signal processing circuit 5. In the second observation satellite 6b, the second angle detector 4b
Detects the sun reflected light of the first mirror ball 9b mounted on the first observation satellite 6a and the sun reflected light of the third mirror ball 9c mounted on the third observation satellite 6c, and outputs angle data. It is transmitted to the processing circuit 5. In the third observation satellite 6c, the third angle detector 4c outputs the sun reflected light from the second mirror ball 9b mounted on the second observation satellite 6b according to the timing signal generated by the third clock 2c. Is detected, and the direction of the mirror ball 9b and the third image pickup device 1c are detected.
Is measured, and the angle data is transmitted to the signal processing circuit 5. Each angle data is transmitted to the ground and recorded in an image database. Also, when performing the altitude extraction processing on the ground, the difference between the position data of the first observation satellite 6a and the position data of the second observation satellite 6b is calculated, and the difference between the position data of the first observation satellite 6a and the second observation satellite 6b is calculated. Similarly to obtaining the relative distance, the relative distance between the second observation satellite 6b and the third observation satellite 6c is also obtained by calculating the difference between the respective position data.

When the altitude is extracted on the ground, the image data of the first image pickup device 1a, the second image pickup device 1b, and the third image pickup device 1c which image the same place on the earth are compared. Since the image data of the first imaging device 1a and the third imaging device 1c has a large difference in the viewing direction, it is difficult to find a corresponding place in the image, and this is different especially when performing automatic matching processing without human intervention. There is a high possibility that a place is mistaken for a matching point. On the other hand, the second imaging device 1b
Image data of the first image pickup device 1a and the image data of the third
It is easy to find the corresponding place in the image with the image data of the image pickup device 1c, so that the possibility of erroneous recognition is low. Therefore, corresponding points between the image data of the first image pickup device 1a and the image data of the third image pickup device 1c are searched based on the image data of the second image pickup device 1b, and as a result, the image of the first image pickup device 1a is obtained. The data is associated with the image data of the third imaging device 1c. In the altitude extraction, the greater the difference between the viewing directions, the better the accuracy. Therefore, the image data of the first imaging device 1a and the third imaging device 1
The altitude is extracted using the image data of c, and the earth surface position coordinates are analyzed. The operation of the equipment provided by the third observation satellite 6c is the same as the operation of the equipment provided by the second observation satellite 6b, except for the operation related to the angle detector 4 and the ground processing. The same is true. Also here mirror ball 9
Has been described, but it goes without saying that the same operation can be performed even when the light source 8 is used. Although the example using three observation satellites 6 is shown here, four or more observation satellites may be used. In this case, another observation satellite that operates in the same manner as the observation satellite 6b of the second observation is placed in the first observation satellite. Observation satellite 6a and the third
May be arranged between the observation satellites 6b.

Embodiment 5 FIG. 9 is a block diagram showing a fifth embodiment of the present invention, in which 2a is a first clock, 2b is a second clock synchronized with the first clock 2a, and 3 is a navigation satellite signal receiver. 4a is a first angle detector, 4b is a second angle detector, 5 is a signal processing circuit, 29
a is the first imaging radar pointing at the earth's surface, 2
9b is a second imaging radar pointing to the same place as the first imaging radar 29a, and 48 is a first imaging radar.
The transmitter 49a transmits a radio wave toward the earth surface as a component of the imaging radar 29a, and the first 49a receives the earth surface reflected wave of the radio wave emitted from the transmitter 48 as a component of the first imaging radar 29a. Receiver,
49b is a second receiver for receiving the earth surface reflected wave of the radio wave emitted from the transmitter 48 as a component of the second imaging radar 29b, and 6a is a second receiver for imaging the earth surface with the first imaging radar 29a. 1 observation satellite, 6b
A second observation satellite 7 which flies in the same orbit as the first observation satellite 6a while maintaining a relative distance approximately equal to the orbit altitude;
Is an image database for recording image data and observation satellite position data and angle data together with time information;
The first light source 8b emits light from the second observation satellite 6a to the second observation satellite 6b, the second light source 8b emits light from the second observation satellite 6b to the first observation satellite 6a, and 10 The ground station, 11 is a navigation satellite, 12 is the earth, the first observation satellite 6a is a first imaging radar 29a,
Clock 2a, navigation satellite signal receiver 3, first angle detector 4a, signal processing circuit 5, first light source 8a, and second observation satellite 6b is equipped with a second imaging radar 29.
b, a second clock 2b, a navigation satellite signal receiver 3, a second angle detector 4b, a signal processing circuit 5, and a second light source 8b.

When a synthetic aperture radar, for example, is used as the imaging radar 29, the first observation satellite 6a is a component of the first imaging radar 29a according to an imaging timing signal generated by the first clock 2a. The transmitter 48 transmits a pulse-shaped radio wave toward the earth 12, receives the ground-surface reflected wave by the first receiver 49a, and transmits data to the signal processing circuit 5. Further, the first clock 2 a transmits time information at which the imaging timing signal is generated to the signal processing circuit 5. Further, the time information at which the first receiver 49 a receives the pulsed radio wave is transmitted to the signal processing circuit 5. Second
In the observation satellite 6b, the ground-surface reflected wave of the pulsed radio wave transmitted by the transmitter 48 is received by the second receiver 49b, and the data is transmitted to the signal processing circuit 5. Since the second clock 2b is accurately time-synchronized with the first clock 2a, the second receiver 49b transmits to the signal processing circuit 5 time information at which radio waves are received.

From the data acquired by the first imaging radar 29a, the first imaging radar 29a is determined based on the time from when the transmitter 48 transmits the pulsed radio wave to when the first receiver 49a receives the reflected wave. The image data is generated by calculating the distance between the object and the ground surface. From the data acquired by the second imaging radar 29a, the time from when the transmitter 48 transmits the pulsed radio wave to when the transmitter 48 reaches the ground surface can be known from the data acquired by the first imaging radar 29a. The distance between the second imaging radar 29a and the ground surface is calculated based on the time until the receiver 49b receives the reflected wave to generate image data. Since the reflected wave of the pulsed radio wave emitted at a certain time and the reflected wave of the next pulsed radio wave transmitted from the transmitter 48 are not confused in the receiver 49b, the distance between the observation point on the ground surface and the first observation satellite 6a is reduced. The observation place is selected such that the relative distance is substantially equal to the relative distance between this observation point and the second observation satellite 6a. In this way, a precise earth surface image can be acquired in the same manner as an optical imager, so that a pair of stereoscopic images can be acquired by combining images at the same place on the earth acquired from a plurality of different directions.

Since the image of the synthetic aperture radar includes random noise called speckle noise, the number of looks for imaging the same point is set to a plurality of times when a continuous image is obtained. Next, by averaging the images at the same point in the ground processing, it becomes possible to remove speckle noise, and it is possible to remove errors in the density of the image. In addition, distortion called so-called fore shortening occurs in the image of the synthetic aperture radar. Therefore, by performing correction processing, geometric correction unique to the imaging radar 29 is performed. Furthermore, as in the case of an optically picked-up image, matching processing of corresponding points at corresponding locations in a plurality of images can be performed according to the density characteristics of the image, so that elevation can be extracted by stereoscopic vision, as in the first embodiment. And the shape of the earth can be analyzed. Other operations are the same as in the first embodiment. It is also possible to measure the relative height difference in a series of images by generating an interferogram by interfering with multiple image data instead of stereoscopic parallax in ground processing. Etc. can be used as auxiliary data.

Embodiment 6 FIG. FIG. 10 is a block diagram showing a sixth embodiment of the present invention, in which 2a is a first clock, 2b is a second clock synchronized with the first clock 2a, and 3 is a navigation satellite signal receiver. 4a is a first angle detector, 4b is a second angle detector, 5 is a signal processing circuit, 29
a is the first imaging radar pointing at the earth's surface, 2
9b is a second imaging radar pointing to the same place as the first imaging radar 29a, and 48 is a first imaging radar.
The first transmitter 48b for transmitting radio waves toward the earth surface as a component of the imaging radar 29a is different from the first transmitter 48a for the earth surface as a component of the second imaging radar 29b. A second transmitter for transmitting radio waves having frequency or polarization characteristics, 49a
Is a first receiver as a component of the first imaging radar 29a which receives the earth surface reflected wave of the radio wave emitted from the first transmitter 48a and the second transmitter 48b, respectively, and 49b is a second receiver. As the components of the imaging radar 29b, the first transmitter 48a and the second transmitter 4
The second receiver 6a receives the earth surface reflected wave of the radio wave emitted from the first imaging radar 8b.
A first observation satellite 9a for imaging the earth's surface at 9a, a second observation satellite 6b flying in the same orbit as the first observation satellite 6a while maintaining a relative distance equivalent to orbital altitude, and 7 as image data An image database for recording position data and angle data of observation satellites together with time information; 8a, a first light source for emitting light from the first observation satellite 6a to the second observation satellite 6b; A second light source 10 emits light from the satellite 6b to the first observation satellite 6a, 10 is a ground station,
11 is a navigation satellite, 12 is the earth, and the first observation satellite 6a is a first imaging radar 29a, a first clock 2a, a navigation satellite signal receiver 3, a first angle detector 4a,
A signal processing circuit 5 and a first light source 8a are mounted, and a second observation satellite 6b is equipped with a second imaging radar 29b and a second imaging radar 29b.
, A navigation satellite signal receiver 3, a second angle detector 4b, a signal processing circuit 5, and a second light source 8b.

In the second observation satellite 6b, the second transmitter 4 which is a component of the second imaging radar 29b according to the imaging timing signal generated by the second clock 2b.
8b transmits a pulsed radio wave toward the earth 12, receives the ground surface reflected wave by the second receiver 49b, and transmits data to the signal processing circuit 5. Further, the second clock 2 b transmits time information at which the imaging timing signal is generated to the signal processing circuit 5. Further, the second receiver 49 b transmits to the signal processing circuit 5 time information at which the second receiver 49 b receives the pulsed radio wave. In the first observation satellite 6a, the ground-surface reflected wave of the pulsed radio wave transmitted by the second transmitter 48b is received by the first receiver 49a, and the data is transmitted to the signal processing circuit 5. The time information at which the first receiver 49 a receives the radio wave is transmitted to the signal processing circuit 5. The first transmitter 48a divides the frequency band into L bands, and the second transmitter 48b divides the frequency band into C bands. If the circuits corresponding to both frequency bands are independent on the receiver side, both bands are separated. The transmission timing of the pulsed radio wave may be arbitrarily set because there is no concern that the radio wave is mixed and the signal is erroneously received, but the first transmitter 48a uses the L-band horizontal polarization and the second transmitter 48b. In the case where there is a possibility that both radio waves are complicated and the signal is erroneously received due to the vertical polarization of the L band, the first transmitter 48a transmits the pulsed radio wave and then the first receiver 49a. And the second receiver 49b
And the time interval until the first transmitter 4 receives the reflected wave.
In the time interval until the next pulse-shaped radio wave is transmitted by the second clock 2a, a timing at which a signal is not erroneously received is selected, an imaging timing signal is generated by the second clock 2b, and the second transmitter 48
b transmits a pulsed radio wave. Other operations are the same as in the fifth embodiment.

Embodiment 7 FIG. 11 is a configuration diagram showing image data according to Embodiment 7 of the present invention, and shows a method of adding time information using a line sensor type image pickup device as an example. In the figure, 22 is image data, 23 is an image header, 24 is line data, 25 is a line header, 2
Reference numeral 6 denotes data at the same imaging timing, and reference numeral 27 denotes each pixel data. In an imager using a line sensor, a plurality of pixels are arranged in one horizontal line orthogonal to the satellite traveling direction, and each pixel data in one horizontal line is acquired at the same imaging timing.
When the imaging is repeated at a specified time interval, the satellite position advances in accordance with the time progress, so that an image in the traveling direction can be acquired, and the data becomes two-dimensional image data. The configuration of the image data 22 includes an image header and each pixel data as in the conventional technology. In the present invention, a set of pixel data 27 newly acquired at the same timing is set as data 26 at the same imaging timing, and the line header 25 is added to configure the line data 26. Further, in the image header, not only the image acquisition year / month / day but also the time when the imaging was started is described in detail. For example, in the case of an image capturing apparatus that captures images every 40 microseconds, the time is described in units of 1 microsecond. In addition, the last three digits of the time are recorded as each line header. Since the time is a variable that monotonically increases, the correct time is not lost even if the number of digits increases. In the example of FIG.
This is an example in which imaging is started at 10: 20: 0.000901 on July 30, 1999, and imaging is performed approximately every 40 microseconds. However, since the amount of data is enormous because time information is added, it is a problem. In this example, an imaging start time is recorded in an image header, and only a three-digit number on the order of microseconds is recorded in a line header. Although the imaging time in the fourth column is 1024 microseconds, the time is not lost even if the first digit is omitted.
However, the satellite position data and the line-of-sight angle data need not always be acquired at the same frequency as the image data is captured. Needless to say, additional information recorded by the conventional technique, information for identifying the data format, an error correction signal, and the like may be recorded in the image header and the line header.

Embodiment 8 FIG. FIG. 12 is a diagram showing an example of an anti-aircraft sign according to Embodiment 8 of the present invention. In the figure, 1a is a first imager, 1b is a second imager, and 6a is a first imager.
, 6b is the second observation satellite, 31a is the first anti-aircraft sign, 31b is the second anti-aircraft sign, 31c is the third anti-aircraft sign, 31d is the fourth anti-aircraft sign, 31e is the fifth anti-aircraft sign Signs 32 are a group of anti-aircraft signs, and all the anti-aircraft signs 31 have already measured position coordinates by navigation satellites or geodetic satellites. The anti-aircraft sign 31 has a geometric shape drawn by a circle, a straight line, or a diagonal line having a size several times as large as the ground resolution of the imaging device 1, and the center position can be identified by looking at the taken image.
Further, the anti-aircraft sign group 32 has a geometric shape in which a plurality of the anti-aircraft signs 31 are arranged. In the example of FIG. 12, the second anti-aircraft sign 31b and the third anti-aircraft sign 31c are based on the first anti-aircraft sign 31a. Are lined up in a direction perpendicular to the satellite travel direction,
The distance between the second anti-aircraft sign 31b and the third anti-aircraft sign 31c is set to be slightly smaller than the range of the image acquired by the imaging device 1. Similarly, the fourth antiaircraft sign 31d and the fifth antiaircraft sign 3
1e are arranged in the satellite traveling direction, and the second anti-aircraft sign 31
The distance between b and the third anti-aircraft sign 31c is also set to a distance slightly smaller than the range of the image acquired by the imaging device 1. Looking at the image captured so that the first anti-aircraft sign 31a appears in the center, the position coordinates of each anti-aircraft sign are known, so that the angle of the satellite's line of sight can be corrected. Further, the first imaging device 1a and the second
If the same anti-aircraft sign group 32 is imaged by the image pickup device 1b, the position and attitude of the observation satellite imaged can be estimated from the degree of inclination of the image data. Therefore, ground verification of the position data and angle data measured in orbit Becomes possible.

Next, a method of correcting the angle of the line of sight will be described with reference to FIG. FIG. 13 is a schematic diagram in which an anti-aircraft sign 31 is captured in image data acquired by a line sensor type imaging device, and is an example in which the image data has the configuration according to the seventh embodiment. In the figure, 22 is image data, 2
3 is an image header, 25 is a line header, 31a is a first antiaircraft sign, 31b is a second antiaircraft sign, and 31c is a third antiaircraft sign. Assuming that the time at which the observation satellite captures the first anti-aircraft sign 31a is T1, and the calculation result obtained from the satellite position data and the line-of-sight angle data is T1, the corresponding time in the image data 22 is the combination of the image header 23 and the line header 25. In the example of FIG. 13, the first anti-aircraft sign 31a should have been captured at the position of T1 = t13, but the actual imaging time is t9, so the value recorded in the angle data has an error. In fact, it can be seen that the inclination was more in the satellite traveling direction than the value of the angle data. Further, since the inclination amount can be converted from the ground conversion distance of the image, the angle of the line of sight can be calibrated on the ground using the antiaircraft sign. Further, if the line sensor is set so as to be orthogonal to the satellite traveling direction, the first anti-aircraft sign 31a and the second anti-aircraft sign 31b
And the third anti-aircraft sign 31c should be imaged at the same timing, but in the example of FIG. Since this shift amount can be converted to the inclination angle of the line sensor using the ground conversion distance of the image, the angle of the line of sight can be calibrated on the ground using the anti-aircraft sign.

[0077]

According to the first embodiment of the present invention, it is possible to measure without using a measuring instrument on the ground by using the earth surface image data viewed from space, so that the entire earth surface can be quantified as three-dimensional information. There is an effect that can be made. In addition, there is an effect that data in an area that does not reach human activities can be measured. In addition, if a set of facilities is constructed, there is no need for other ground facilities, so that there is an effect that a large amount of data can be acquired at low cost.

Further, since the positions and angles of two points on the orbit of the observation satellite are measured and a stereoscopic survey is performed from two known points, the absolute coordinates of the ground surface can be obtained even if there is no reference point such as an anti-aircraft sign. It has the effect of being able to measure. In addition, since it is not necessary to have a location on the ground where the relative distance is known, there is an effect that the position between continents and island countries across the ocean can be measured.

Further, since it is a geometrical measuring method not including the gravitational effect, there is an effect that the measurement can be performed without being affected by the bias of gravity. Further, there is an effect that it is possible to realize an observation satellite that flies in an orbit capable of imaging the entire surface of the earth with an on-board image pickup device and to perform high-resolution measurement corresponding to small-scale undulations.

In addition, since time is managed using atomic clocks having high frequency stability and mutually adjusted, there is an effect that measurement can be performed with a common time reference regardless of time and place. In addition, since the rotation of the earth is not used as a time reference, there is an effect that the absolute time accuracy is high and high-accuracy measurement with few errors due to the time accuracy can be performed.

Further, since the coordinates of the earth surface position can be measured by a single coordinate system operating a navigation satellite, there is an effect that a map of each country can be created on a unified coordinate system. In addition, there is an effect that a map of each country can be positioned with an accuracy of about several tens of meters.

In the position measurement using the navigation satellite, the satellite 1
By utilizing the difference between the two points of position data, which cannot improve the measurement accuracy only by measuring the position of the platform, the satellite position errors become equal to each other and are canceled out, so that the analysis accuracy is improved. Since the distance between two satellites can be grasped with high accuracy, there is an effect that it is possible to perform aerial triangulation with high measurement accuracy.

Since the angle of the line of sight is measured with reference to an observation satellite flying in the same orbit or an adjacent orbit while maintaining the relative distance, it is possible to perform aerial triangulation with high measurement accuracy. .

According to the second embodiment of the present invention, there is an effect that the same effect as that of the first embodiment can be obtained without power consumption on orbit since the mirror ball does not require a power source. In addition, there is no fear of failure, so that a highly reliable device can be configured. Other effects are the same as those of the first embodiment.

According to the third embodiment of the present invention, the relative positions of the three observation satellites that have acquired the images are determined, and the angles of the line-of-sight directions are also determined. There is an effect that altitude can be extracted.
In addition, even if there is an area where the same shape repeats periodically on the earth's surface and it is difficult to perform matching processing to find a corresponding point in one stereoscopic pair, it is easy to perform matching processing with another stereoscopic pair. Earth surface position coordinate analysis with less noise. Furthermore, since position coordinate data can be generated by a plurality of combinations, there is an effect that unique data can be specified and removed by cross-checking each other. Also, depending on the characteristics of the surface shape, even if there is a terrain that is hidden behind a high mountain when viewed from a specific direction, the data can be interpolated by stereoscopic data using an image viewed from another direction. Therefore, there is an effect that the credibility of the data is increased. Also, if only two of the observation satellites form a pair as in the first embodiment, if one of the observation satellites fails to launch or fails, the elevation analysis by stereoscopic vision cannot be performed. It has the effect of playing a role.

According to the fourth embodiment of the present invention, since the error in the matching process of the stereoscopic pair image is reduced, there is an effect that the accuracy of the earth surface position coordinates is improved. In addition, there is an effect that the matching processing which requires the most human intervention in the earth shape analysis processing according to the present invention can be automated. In addition, the ability to automate has the effect of facilitating the processing of vast amounts of observation data across the globe. In addition, since many observation satellites can be added in a bead shape, there is an effect that there is a high degree of freedom in replacing or adding observation satellites due to failure or life. Also, when only two of the observation satellites form a pair as in the first embodiment, if one of the observation satellites fails to launch or breaks down, the elevation analysis by stereoscopic vision cannot be performed.
According to this, there is an effect that it plays a role of the superior configuration.

According to the fifth embodiment of the present invention, an imaging radar using a microwave can acquire image data through a cloud unlike an optical image pickup device in which an image is blocked by a cloud. There is an effect that data can be reliably obtained. In addition, the optical imaging device cannot be used for analysis because the image is too dark in high latitudes and polar regions where the sun reflected light is small, whereas the imaging radar using microwaves can acquire images in the region without sunlight irradiation Therefore, there is an effect that topographical data of a polar region characteristically showing an earth elliptical shape can be effectively acquired. In addition, imaging radars usually require a large amount of transmission power using a large-capacity power supply, and in order to use multiple imaging radars, transmitters are required according to the number of units, and appropriate power and transmission power are required. However, according to the present invention, there is an effect that a plurality of imaging radar outputs can be obtained only by one set of transmitter and its power supply and power.

According to the sixth embodiment of the present invention, since the reflection characteristics of a substance differ depending on the frequency band, there is an effect that, for example, in a forest area, the position of the ground and the position of the top of the forest can be measured separately. In addition, a normal imaging radar requires a large amount of transmission power using a large-capacity power supply. Therefore, mounting an imaging radar of a plurality of frequency bands on a single satellite is not feasible due to restrictions on power generated by the satellite. Although it was difficult, according to the sixth embodiment of the present invention, since transmitters of different frequency bands can be mounted on different satellites, there is an effect that an apparatus for measuring a plurality of frequency bands and polarization characteristics can be easily realized. Further, there is an effect that data sets of different frequency bands and polarization characteristics obtained by simultaneously measuring the same place on the earth can be effectively acquired. Needless to say, the same effects as in the fifth embodiment are obtained.

According to the seventh embodiment of the present invention, the time at which an image was taken can be accurately grasped, so that there is an effect that measurement can be performed with high positional accuracy. In addition, since the time histories of all shooting timings are attached to the image data, there is an effect that the swaying and attitude fluctuation of the satellite can be corrected using the satellite position and line-of-sight direction information at each imaging time. Further, since the time is managed using the atomic clocks having high frequency stability and mutually adjusted, there is an effect that the measurement can be performed based on a common time reference regardless of time and place.

According to the eighth embodiment of the present invention, there is an effect that the position and the angle can be calibrated on the ground as points having known position coordinates in the image. Further, since the time history of the imaging timing is attached to the image data, and the satellite position and the line-of-sight direction information at the imaging time can be calibrated, there is an effect that the pointing error of the imaging device and the satellite attitude fluctuation can be corrected. In addition, since the number of ground calibration points increases with an increase in the number of anti-aircraft signs, there is an effect that the image data conventionally stored in the image database can be reused and the data can be updated with higher accuracy than before.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing Embodiment 1 of an earth shape measuring apparatus according to the present invention.

FIG. 2 is a schematic diagram of a satellite orbit according to Embodiment 1 of the present invention.

FIG. 3 is a diagram illustrating a principle of altitude extraction based on parallax of stereoscopic vision of the earth shape measuring apparatus according to the present invention.

FIG. 4 is a diagram showing a structural example of an image database of the earth shape measuring apparatus according to the present invention.

FIG. 5 is a diagram showing an example of a method of accurately determining the absolute position coordinates of the observation satellite of the earth shape measuring apparatus according to the present invention.

FIG. 6 is a configuration diagram showing Embodiment 2 of the earth shape measuring apparatus according to the present invention.

FIG. 7 is a configuration diagram showing Embodiment 3 of the earth shape measuring apparatus according to the present invention.

FIG. 8 is a configuration diagram showing a fourth embodiment of the earth shape measuring apparatus according to the present invention.

FIG. 9 is a configuration diagram showing Embodiment 5 of the earth shape measuring apparatus according to the present invention.

FIG. 10 is a configuration diagram showing Embodiment 6 of the earth shape measuring apparatus according to the present invention.

FIG. 11 is a configuration diagram showing image data according to a seventh embodiment of the earth shape measuring apparatus according to the present invention.

FIG. 12 is a diagram showing an example of an anti-aircraft sign according to Embodiment 8 of the earth shape measuring apparatus according to the present invention.

FIG. 13 is a schematic diagram in which an anti-aircraft sign 31 is captured in image data of the earth shape measuring apparatus according to the present invention.

FIG. 14 is a diagram showing a satellite triangulation device as an example of a conventional earth shape measurement device.

FIG. 15 is a principle diagram of satellite triangulation as an example of a conventional earth shape measuring device.

FIG. 16 is a diagram showing an aerial triangulation device as another example of the conventional earth shape measurement device.

[Explanation of symbols]

1 imager, 2 clock, 3 navigation satellite signal receiver, 4
Angle detector, 5 signal processing circuit, 6 observation satellite, 7 image database, 8 light source, 9 mirror ball, 10
Ground station, 11 navigation satellites, 12 earth, 13 spheroid, 14 line of sight of imager, 15 orbit of observation satellite, 16
Orbit of navigation satellite, 17 position of observation satellite, 18 intersection C of line of sight, 19 observation target point D on the surface of the earth, 20 parallel line with the line of sight of the imager passing through D, 21 position of D in the image of the imager, 22 Image data, 23 image headers, 24 line data, 25 line headers, 26 data at the same imaging timing, 27 pixel data, 28 headers, 2
9 imaging radar, 30 satellite position data, 31
AA sign, 32 AA sign group, 33 Angle data, 3
4 geodetic satellites, 35 reference points, 36 cameras, 37 geodetic locations, 38 orbits of geodetic satellites, 39 straight lines with known distances, 40 straight lines with unknown distances, 41 geodetic satellite positions s1 at time t1, 42 geodesic at time t2 Satellite position s2, 43 aircraft, 44 camera view range,
45 image data block, 46 position data block, 47 angle data block, 48 transmitter, 49
Receiving machine.

Claims (8)

(57) [Claims] 1. An image pickup device pointing to the earth's surface, a clock for generating a timing signal by measuring a time at which the image pickup device performs imaging, an image signal acquired by the image pickup device, and a timing signal generation time when the clock is generated. A signal processing circuit that processes the data in a form capable of transmitting data to the ground, receiving a signal indicating a position coordinate of the position of the image pickup device according to a timing signal generated by the clock, and transmitting time information to the signal processing circuit. A navigation satellite signal receiver that transmits data together, a light source that emits light to the outside of the satellite, a light emitted by another satellite in response to a timing signal generated by the clock, and a line-of-sight direction of the imager and a direction of the light source An angle detector that detects the relative angle to and transmits the data together with the time information to the signal processing circuit, the image data acquired by the imager and the image data acquired by the navigation satellite signal receiver An image database that records the position data, the angle data obtained by the angle detector, and the time information at which the clock generated the timing signal, and an on-orbit position that generates a radio wave for measuring a distance using radio wave propagation time Is composed of a plurality of known navigation satellites,
And while flying the same orbit while maintaining the same relative distance as the orbit altitude while imaging the same place on the ground as the observation satellite, the angle detector detects the light emitted from each other's light source and the angle in the line-of-sight direction An earth shape measuring device having a pair of observation satellites for measuring the distance. 2. An image pickup device pointing at the earth's surface, a clock for generating a timing signal by measuring a time when the image pickup device performs imaging, an image signal acquired by the image pickup device, and a timing signal generation time when the clock is generated. A signal processing circuit that processes the data in a form capable of transmitting data to the ground, receiving a signal indicating a position coordinate of the position of the image pickup device according to a timing signal generated by the clock, and transmitting time information to the signal processing circuit. A navigation satellite signal receiver that transmits data together with it, a mirror ball that lays mirror pieces in a spherical shape to reflect sunlight, and a line of sight of the imager that detects light emitted by other satellites in response to a timing signal generated by the clock. An angle detector for detecting a relative angle between the direction and the direction of the light source and transmitting data together with time information to the signal processing circuit; image data acquired by the imager; An image database for recording the position data obtained by the star signal receiver and the angle data obtained by the angle detector together with the time information at which the clock generated the timing signal, and for measuring the distance using the radio wave propagation time Flying in the same orbit while maintaining the same relative distance as the orbit altitude while imaging the same location on the surface of the earth as the observation satellite, the on-orbit position where the radio wave is generated is composed of a plurality of known navigation satellites, An earth shape measuring device having a pair of observation satellites for detecting the angle of the line of sight by detecting the sun reflected light emitted from each mirror ball by the angle detector. 3. An image pickup device pointing to the earth's surface, a clock for generating a timing signal by measuring a time at which the image pickup device performs imaging, an image signal acquired by the image pickup device, and a timing signal generation time when the clock is generated. A signal processing circuit that processes the data in a form capable of transmitting data to the ground, receiving a signal indicating a position coordinate of the position of the image pickup device according to a timing signal generated by the clock, and transmitting time information to the signal processing circuit. A navigation satellite signal receiver that transmits data together with a light source or a mirror ball that emits light toward the outside of the satellite, detects the light emitted by other satellites in response to the timing signal generated by the clock, and changes the line-of-sight direction of the imager. An angle detector for detecting a relative angle with respect to the direction of the light source and transmitting data together with time information to the signal processing circuit, image data acquired by the imager and the navigation satellite signal; An image database that records the position data obtained by the signal receiver and the angle data obtained by the angle detector together with the time information at which the clock generated the timing signal, and a radio wave for measuring the distance using the radio wave propagation time The orbital position at which the trajectory is generated is composed of a plurality of navigation satellites with known positions, and the relative distance of the same level as the orbital altitude between the other two observation satellites while imaging the same place on the surface of the earth as the observation satellite. While flying in an adjacent orbit while maintaining
An earth shape measuring apparatus having a set of three observation satellites for detecting the light emitted from the other two observation satellites and measuring the angle of the line of sight of the imaging device. 4. An image pickup device pointing at the earth's surface, a clock for generating a timing signal by measuring the time at which the image pickup device performs imaging, an image signal acquired by the image pickup device, and a timing signal generation time when the clock is generated. A signal processing circuit that processes the data in a form capable of transmitting data to the ground, receiving a signal indicating a position coordinate of the position of the image pickup device according to a timing signal generated by the clock, and transmitting time information to the signal processing circuit. A navigation satellite signal receiver that transmits data together with a light source or a mirror ball that emits light toward the outside of the satellite, detects the light emitted by other satellites in response to the timing signal generated by the clock, and changes the line-of-sight direction of the imager. An angle detector for detecting a relative angle with respect to the direction of the light source and transmitting data together with time information to the signal processing circuit, image data acquired by the imager and the navigation satellite signal; An image database that records the position data obtained by the signal receiver and the angle data obtained by the angle detector together with the time information at which the clock generated the timing signal, and a radio wave for measuring the distance using the radio wave propagation time The on-orbit position at which the trajectory is generated is composed of a plurality of navigation satellites whose known positions are the same as the above-mentioned observation satellites. An earth shape measurement device having three or more observation satellites that flies in the same orbit while maintaining the relative distance of the above and that detects the light emitted by the observation satellites before and after to measure the angle of the line of sight of the imaging device. 5. An earth shape measuring apparatus using an imaging radar as an imager, wherein one imaging radar has a transmitter, and all the imaging radars receive ground-surface reflected waves of a signal emitted from the transmitter. And generating a radar image.
The earth shape measuring device according to any one of the above. 6. An earth shape measuring apparatus using an imaging radar as an imager, one imaging radar including a transmitter, and another imaging radar having a different frequency or polarization from the transmitter. A transmitter having wave characteristics, and all imaging radars
5. A radar image is generated by receiving ground reflection waves of signals emitted from two transmitters.
The earth shape measuring device according to any one of the above. 7. The earth shape according to claim 1, wherein in the earth shape measuring device, the time of all the imaging timings is added to the image data and recorded in the image database in the signal processing section. Measuring device. 8. The earth shape measuring device according to claim 1, wherein the earth shape measuring device is provided with an anti-aircraft sign whose position coordinates have been measured in advance by a navigation satellite or a geodetic satellite on the surface of the earth. apparatus.