JPH06167563A - Gp position measuring system - Google Patents

Abstract

PURPOSE:To provide a differential GPS position measuring system which is accurate over a wide area. CONSTITUTION:A ground station 10 is dispersed into a plurality of parts in a specific zone. The ground station 10 measures its own position using a plurality of satellites and then calculates position compensation information by a compensation information operation means according to the position measurement value and the absolute position of the ground station 10. The base station 10 processes the position compensation information by a zone-giving means to distinguish the position compensation information for each ground station at a position measuring station 20, and then transmits it to the position measuring station 20. The position measuring station 20 measures its own position using a plurality of satellites and then judges its own presence zone according to the position measurement value. The position measuring station 20 receive a plurality of position compensation information pieces from a plurality of ground stations, selects only the position compensation information from the ground station 10 in its own zone by the compensation information selection means, and then compensates the self position measurement value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to GPS (Global Position
ionizing system), more specifically, a differential G that corrects its own position measured by the positioning station using position correction information from the reference station.
It relates to a PS positioning system.

[0002]

2. Description of the Related Art A GPS positioning system measures the position of oneself using radio waves from a plurality of satellites, and is widely used for confirming the current position of various moving bodies such as humans, ships, airplanes and automobiles. It is starting to be used. However, the positioning value measured by the mobile body includes various errors. The differential GPS positioning system eliminates this error.

A conventional differential GPS positioning system will be described with reference to FIGS. FIG. 8 is a block diagram of a base station of a conventional differential GPS positioning system, and FIG. 9 is a block diagram of a positioning station of a conventional differential GPS positioning system. The absolute position of the base station is known, and the absolute position is (U, V, W).

The base station has a GPS positioning section 72. G
The PS positioning unit 72 positions itself (base station) using the information from the four satellites. 4 satellite numbers (S1, S
2, S3, S4) and the positioning value is (u, v, w). The positioning value (u, v, w) measured by the base station is input to the positioning error calculator 73. The positioning error calculation unit 73 calculates the positioning value (u, v, w) and the absolute position (U, V, w) of the base station.
W) 74, and the position correction values (Δu = u−U, Δv =
v−V, Δw = w−W) is calculated.

The base station performs this calculation for all combinations of visible satellites. Then, the correction information sending unit 75 sends them to the position correction information (Δu, Δv, Δ).
w, S1, S2, S3, S4) is transmitted from the position correction information transmitting antenna 76 to the positioning station.

The positioning station has a GPS positioning section 82 and a correction information receiving section 84. The GPS receiving unit 82 uses the information from the four satellites to position itself (positioning station). The numbers of the four satellites are (Sa, Sb, Sc, Sd), and the positioning values are (u ', v', w '). Further, the correction information receiving unit 84
Receives the position correction information (Δu, Δv, Δw, S1, S2, S3, S4) from the correction information sending unit 75 of the base station from the position correction information receiving antenna 85, and the positioning value correction calculation unit Output to 83.

When the position of the positioning station is measured, the positioning value and the four satellite numbers (Δu ′, Δv ′, Δ) used for the positioning.
w ′, Sa, Sb, Sc, Sd) is the positioning correction calculation unit 83
Entered in. The positioning correction calculation unit 83 selects the same combination of position correction information as the four satellites used for positioning by the positioning station from the position correction information sent from the reference station, and uses the position correction information to determine the positioning value ( u ', v', w ') are corrected and the positioning result (U', V ', W') is output.

[0008]

In the conventional differential GPS positioning system, when the distance between the positioning station and the base station increases, the positioning satellite and the base station see the GPS satellite at the same time and even if they are the same GPS satellite. Since the difference between the elevation angle and the azimuth angle becomes large, the number of the four satellites (Sa, Sb, Sc, Sd) used for positioning by the positioning station and the satellite number of the position correction information sent from the base station should be the same. However, since the elevation angle and the azimuth angle of each GPS satellite from the base station and the positioning station are largely different, the position correction information of the base station having a large distance from the positioning station cannot correct the position of the positioning station.

As described above, there is a problem that the error in the positioning result after the position correction increases as the distance between the base station and the positioning station increases.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a highly accurate differential GPS positioning system over a wide area.

[0011]

[MEANS FOR SOLVING THE PROBLEMS] A differential GPS positioning system for correcting its own position measured by a positioning station using position correction information from a base station, wherein a plurality of base stations are dispersed in a predetermined zone. , GPS positioning means for receiving radio waves from a plurality of satellites to measure its own position, calculating means for comparing the obtained positioning value with its own absolute position and calculating position correction information, and each base station The positioning station is provided with zone assigning means for processing the position correction information in order to distinguish the position correction information of the positioning station, and transmitting means for notifying the positioning station of the calculated position correction information. GPS positioning means for receiving radio waves to measure its own position, receiving means for receiving position correction information sent from the base station, and which zone the self (positioning station) is based on the obtained positioning value. Or It is characterized by comprising a correction information selecting means for making a judgment and selecting only the position correction information transmitted from the base station in the zone, and a correction means for correcting the positioning value using the received position correction information. .

[0012]

In the base station, the GPS positioning means measures the position of the self (base station), and the calculating means calculates the position correction information from the absolute position of the self (base station) and the positioning value. The position correction information is processed by the zone assigning unit so that the position correction information for each base station can be distinguished by the positioning station, and is transmitted to the positioning station by the transmitting means.

The positioning station measures the position of itself (positioning station) by the GPS positioning means, the correction information selecting means determines which zone the positioning station is in from the positioning value, and the base station in the zone determines. Select only the transmitted position correction information.
The correction means corrects the positioning value using the position correction information.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. 1 is an image diagram of a GPS positioning system, FIG. 2 is a block diagram of a base station, and FIG. 3 is a block diagram of a positioning station.

The first zone 1 and the second zone 2 are arranged adjacent to each other, the first base station 10 is located near the center of the first zone 1, and similarly, the first zone 1 is located near the center of the second zone 2. Is the second
There is a base station 30 of It is assumed that the positioning station 20 is a mobile body and is now in the first zone 1.

The base station 10 includes a GPS antenna 11 and a GP.
The S positioning unit 12, the positioning error calculation unit 13, the absolute position 14 of the base station, the zone assigning unit 15, the correction information transmitting unit 16, and the correction information transmitting antenna 17 are included.

The GPS positioning unit 12 GPs radio waves from four GPS satellites (satellite numbers S1, S2, S3, S4).
It receives from the S antenna 11 and measures its own position, and its position measurement value and satellite number (u, v, w, S1, S2, S3).
S4) is output to the positioning error calculator 13. The positioning error calculation unit 13 uses the positioning values (u, v,
w) and the base station absolute position 14 (U, V, W) are compared, and the position correction values (Δu = u−U, Δv = v−V, Δw = w−) are compared.
W) is calculated, and the position correction information (Δu, Δv, Δw, S
1, S2, S3, S4) are formed and output to the zone providing unit 15. The zone assigning unit 15 processes the position correction information sent from the positioning error calculation unit 13 so that the positioning station can identify the position correction information as the position correction information of the first zone, and outputs it to the correction information sending unit 16 for correction. It is transmitted from the information transmitting antenna 17. The base station 10 does this for all visible satellite combinations.

FIG. 4 shows a detailed block diagram of the zone assigning section 15. The position correction information from the positioning error calculation unit 13 is
The information is modulated by the information modulator 31 and output to the mixer 32. In the PN generator 33, ± driven by the clock 34
The PN sequence determined in advance in the first zone 1 is generated and output to the mixer 32. The mixer 32 multiplies the FM-modulated position correction information and the PN sequence to obtain a spread spectrum signal. The spread spectrum signal is converted into a radio frequency by the frequency conversion unit 35, power is amplified by the amplifier 36, and the correction information transmitting antenna 17 is provided.
Sent by.

Further, the PN sequence is an arbitrary M sequence which is different depending on each zone, which is determined in advance by the zone. If the position correction information of each zone is sufficiently separated to cause no interference, the PN sequence is The same code may be used repeatedly in different zones.

The positioning station 20 has a GPS receiving antenna 21,
It has a GPS positioning unit 22, a positioning correction calculation unit 23, a correction information selection unit 24, a correction information receiving unit 25, and a correction information receiving antenna 26.

The GPS positioning section 22 includes a GPS antenna 21.
4 GPS satellites (satellite numbers Sa, Sb, Sc, S
The position of its own is received by receiving the radio wave from d), and the positioning value and satellite number (u ', v', w ', Sa, Sb, Sc, Sd) are given to the correction information selection unit 24 and the positioning correction calculation unit 23. Output. The correction information receiving unit 25 receives the position correction information transmitted from a plurality of arbitrary base stations, and receives the correction information receiving antenna 26.
It is further received and output to the correction information selection unit 24. The correction information selection unit 24 determines from the positioning value from the GPS positioning unit 22 that the self (positioning station 20) is present in the first zone 1, and the position correction information sent from the plurality of base stations. Among them, only the position correction information (Δu, Δv, Δw, S1, S2, S3, S4) sent from the first base station 10 is selected and output to the positioning correction calculation unit 23. The positioning correction calculation unit 23 uses the satellite number (Sa, Sb,
The position correction information of the same combination of satellite numbers as the combination of Sc, Sd) is selected, and G is selected by the position correction information.
The positioning value (u ', v', w ') from the PS positioning unit 22 is corrected, and the positioning result (U' = u'-Δu, V '= v'-
Δv, W ′ = w′−Δw) is output.

FIG. 5 shows a detailed block diagram of the correction information selecting section 24. The signals from the arbitrary plurality of base stations received from the position correction information receiving antenna 26 are power-amplified by the amplifier 41, frequency-converted by the frequency converter 42, and then output to the mixer 45. In the zone confirmation unit 46, GP
Based on the positioning value from the S positioning unit 22, it determines that the positioning station 20 exists in the first zone, and outputs the first control signal to the PN generating unit 44. The PN generating unit 44 causes the memory in the PN generating unit 44 to read the first zone 1 according to the control signal.
The PN sequence of the above is output to the mixer 45. The mixer 45 performs spectrum despreading by multiplying the frequency-converted signal and the PN sequence, and outputs only the position correction information from the base station 10 in the first zone 1 to the information demodulation unit 47. At this time, the time discrimination control circuit 43 synchronizes the frequency-converted signal with the PN code. In the information demodulation section 47, the spectrum despread signal is FM
It demodulates and outputs to the positioning correction calculation unit 23.

Now, the positioning station 20 moves from the first zone 1 to the second zone.
Suppose you moved to Zone 2 of. Then, the zone confirmation unit 46 of the positioning station 20 determines that it is the second zone 2 based on the positioning value from the GPS positioning unit 22, and sends a second control signal to the PN generation unit 44. In the PN generator 44, PN is generated by the control signal.
The PN sequence of the second zone is output to the mixer 45 from the memory in the generation unit, the spectrum is inversely spread by the PN sequence, and only the position correction information from the second base station 30 is passed through the information demodulation unit 47 to perform the positioning correction calculation. It is output to the unit 23. Therefore, the positioning value from the GPS positioning unit 22 is the second base station 30
It is corrected by the position correction information from.

When spread spectrum is used to perform zone recognition in this way, position correction information from the base stations in each zone can be multiplexed and transmitted with a single carrier frequency. Also, because of the nature of spread spectrum, communication that is resistant to fading and interference from others can be performed, so stable and highly accurate positioning can be performed within the zone.

6 and 7 show another embodiment of the zone adding section 15 and the correction information selecting section 24. 6 is a block diagram of the zone assigning unit 15 on the base station side, and FIG. 7 is a block diagram of the correction information selecting unit 24 on the positioning station side.

In the base station, the position correction information from the positioning calculator 13 is multiplied by the carrier wave from the oscillator 53 in the mixer 51 to obtain an AM modulated signal. The signal is power-amplified by the amplifier 52 and transmitted from the antenna 17. However, the oscillation frequency of the carrier wave is different in each predetermined zone, and if the position correction information of each zone is sufficiently distant so as not to cause interference, the same frequency is used in different zones. May be used repeatedly.

In the positioning station, the position correction information receiving antenna 2
Signals transmitted from any of a plurality of base stations from 6 are received, power is amplified by an amplifier 61 and output to a mixer 62. The zone confirmation unit 65 determines in which zone the self (positioning station) exists based on the positioning value from the GPS positioning unit 22,
An oscillating frequency controlling DC current that produces the same frequency as the carrier frequency of the zone is sent to the voltage controlled oscillator 63. The voltage control oscillator 63 sends a carrier wave having a frequency determined by the DC current to the mixer 62.
Mixer 62, low pass filter (LPF) 64
Outputs the signal output from the amplifier 61 to the positioning correction calculation unit 23 by demodulating the signal output from the amplifier 61 with only the position correction information from the base station in the zone.

By performing zone recognition by making the frequency different for each base station in this way, the circuit configuration of both the zone assigning unit 15 of the base station and the correction information selecting unit 24 of the positioning station becomes simple.

[0029]

As described above, in the GPS positioning system according to the present invention, the wide area is divided into predetermined small zones, the base station is provided in each zone, and the differential G is provided for each zone.
Since the PS positioning is performed, the distance between the positioning station and the base station is suppressed within a certain value, and the accuracy of positioning correction caused by the distance is reduced. As a result, the positioning station can perform highly accurate positioning within the zone, and by changing the zone as the positioning station moves, it is possible to perform highly accurate positioning over a wide area.

[Brief description of drawings]

FIG. 1 is an image diagram of a GPS positioning system showing an embodiment of the present invention.

FIG. 2 is a block diagram of a base station of a GPS positioning system showing an embodiment of the present invention.

FIG. 3 is a block diagram of a positioning station of a GPS positioning system showing an embodiment of the present invention.

FIG. 4 is a block diagram of a zone assigning unit of a base station according to an embodiment of the present invention.

FIG. 5 is a block diagram of a correction information selection unit of the positioning station according to the embodiment of the present invention.

FIG. 6 is a block diagram of a zone adding unit of a base station according to another embodiment of the present invention.

FIG. 7 is a block diagram of a correction information selection unit of a positioning station according to another embodiment of the present invention.

FIG. 8 is a block diagram of a base station of a conventional differential GPS positioning system.

FIG. 9 is a block diagram of a positioning station of a conventional differential GPS positioning system.

[Explanation of symbols]

 1 1st zone 10 1st base station 12 GPS positioning part 13 Positioning error calculation part 15 Zone provision part 16 Correction information transmission part 20 Positioning station 23 Correction information calculation part 24 Correction information selection part 25 Correction information reception part

Claims (1)

[Claims] 1. A differential GPS positioning system that corrects its own position measured by a positioning station using position correction information from a base station, wherein a plurality of base stations are dispersed in a predetermined zone, and a plurality of satellites are used. GPS positioning means for receiving a radio wave from the vehicle to measure its own position, calculation means for comparing the obtained positioning value with its own absolute position to calculate position correction information, and position correction information for each base station The positioning station includes zone adding means for processing the position correction information in order to distinguish between the positioning stations and transmitting means for notifying the positioning station of the calculated position correction information. The positioning station receives radio waves from a plurality of satellites. GPS positioning means for positioning the position of itself, receiving means for receiving the position correction information sent from the base station, and which zone the self (positioning station) is in is determined by the obtained positioning value. , The above A GPS wide area high-performance device comprising: a correction information selecting unit that selects only position correction information transmitted from a base station in the network; and a correction unit that corrects a positioning value using the received position correction information. Precision positioning system.