CA2191954A1 - Method for the collection, analysis, measurement and storage of geographical data - Google Patents

Abstract

The invention concerns a method for the collection, analysis, measurement and storage of geographical data, the aim being to guarantee user-relevant data handling and simplified availability in large, medium and small user centres and to ensures the optimization of existing components in digital stereo work stations with facilities for interactive overlay, truing and execution of digitally recorded landscape, planning and property data or land-register maps as well as the addition of alphanumeric data. This aim is achieved as shown in the figure by virtue of the fact that a topographic surface (zone 1) is recorded using aerial photography by an aircraft (2) whose position is determined by means of DGPS signals from satellites (3). A digital height model (4) is subsequently derived by data processing or calculated after the fourth operational step. From the topographic surface (zone 1) and the digital height model, including the known positions of the projection centres at the time the photograph was taken by the aircraft (2), and by mathematical transformation of the analogue aerial photo or of a digital aerial-photo scene, the digital orthophoto (5) is generated and made available to a potential user on a data-storage medium, thus enabling the potential user to add, to the digital orthophoto (5), vector/line graphics (6) and to make use of it depending on the task specification and necessary decision-making capacity which he, as mandator, has formulated.

Description

~ 2~91~54 Wo 95/33973 ' ~CT/DE 95/C~639 ~E~HOD FO~ THE Co~LECTION, ANALYSIS, MEASUREM~T AND
S~o~AGE OF GEOGRAPHICA~ ~ATA

The invention relates to a method for the collection, analysis, measurement ana storage o~ geographical data and is intended for manifold space-arranging provisions o~ planning and decision-making institutions in government, public planning corporations, private planners, architects, and engineers. This accordingly involves city planning, land reallotment, land use planning predoninantly in rural areas, and planning of traf~ic infrastructure provisions (roads, rails, waterways, land records, regional pl~nni~g, agrarian planning, forestry, ana envi~ 1 protection~.
current technology in handling sur~eying tasks is based on the extensive development in screen image procesSing, CAD, and screen-image graphics integration, including associated alp~m~r~rical information (attributes) in so-called geographical data processing systems. Analog images can be digitized with high resolution. For processing the large amount of data created in the process, an appropriate computation techni~ue is available. German Patent Publication DE A 32 19 032 discloses an embodiment in which the intent is to recover the orientation data from an aerial camera and a digital terrain form model. Three sensor lines arranged transversely or obli~uely to the flight direotion, and an associated optical element are used. By continuous line scanning, three image strips of the terrain are produced, each taken from a different perspective. To that end, it is proposed that pixels distributed in a mesh, preferably in the middle strip of the image, be specified; that the corresponding pixels and the associated line numbers be determined by area cor~ection in the other two image strips; to approximate the orientation parameters of the camera from the approximately known flight 2~9~954 ~~ 95/33973 PCT/DE 95~0639 motions for every point, and by three-dimensional foresiqhting to determine the terrain coordinates o~ the point approximately: to set up beam intersection connections for the three beams belonging to one point; and via error e~u~tions and a compens'ation process to ascçrtain the rost likely and final values of the orientation parameters and the point-terrain coordinates.
An embodiment according to l~uropean Patent Publication EP A 0 237 601 is also known, according to which the photogram~etric detection of an object is done with the aid of an optoelectronic solid-state area sensor in the form of partial images via a large image format, i~ the position of the sensor is ~P~rminP~ in the image plane by means of a network. This can be done by copying at least one network mesh in the sensor irage. After the network points in the coordinate system of the partial image are measured and transformed to the desired ~alues in the system of the network, the position of the area sensor and transformation parameters for all the pixels within the network mesh are ootained. To that end, the approximation position of the sensor must be ade~uately well known to enable ~etPrm;nlng the number of the network mesh as an une~uivocal iaentification of the network points.
According to German Patentpublication DE A 381)2541, i~ is known tTlat in initial aerial i~age-taking flights at an altitude of between about 150 m and 500 m above the ground, aerial survey pictures are collected, taken with prospecting cameras (2) in combination with telecham~ers (3) for producing detail pictures from the regional detail covered by the prospecting cameras (2). The aerial survey lmages are defined by ~eans of orientation aids with respect to their actual position on the ground and evaluated using methods of photogrammetry.
The ascertained ground position data of a structure are .

3 ~CT/D~ 95/0~639 associated, in such a way that they can be called up selectively, with the t-n~rtl;nAteS of the structure on the ground.
According to German Patent Publication DE A 383057~, the forming of the object pixel signals is done by digital control of the sampling period ~ty of the a priori analog, parallel deteCtOr signals and their storage in (M) memories, from which an analog line signal s(t) is formed by serial readout, which line signal is sampled in (n) constant periods Atx, and from that the final slgnals corresponding to the object pixels (B) are formed; the sanpling periods ~ty and ~tx each represent functions of the sampling distance (E) or flight altitude (h) ana the sampling angle (w).
~ :ast German Patent Publication DD 237211 relates to a circuit arrangement for automatically operating a photogrammetry camera. It can be used to produce serial aerial pictures and is intended to aid in precluding defects that can occur i~
the camera is operated ~anually, and to reduce the burden on the human~operator to a mini~ur.. ~he variables necessary for controlling the photogrammetric camera, such as the ratio of speed to altitude, drift, and exposure time, are ascertained by suitably ~ ~m;nt~fl correlations. Two discrete photoreceiver cells, disposed at right angles to the flight direction and called up in a certain time-slot pattern, furnish relevant information for ~o~ming the control variables regarding the terrain flown over.
A method of gravity surveying from the air according to German Patent Publication DE A 3612674 is based on the use of an aircraft that is stabilized with regard to.speed, course and altitude and that includes a gravity ~eter of suitable sensitivity.
~ts signals and other signalb are plotted with a high ~ampling rate on magnetic tape, so that the location (position) of the aircraft can ~e calculated, etc., either on 2 1 9 ~ 954 the basis of a satellite locating fiystem or a ground based navigation syste~, referred to geodetically precisely known pOints, that ~urnishes a plurality of navigation parameters, such as bearing directions or distances.
A disadvantage is that the aforementioned known embodiments have thus far not be used together, technically and technologically coordinated, for the collection, analysis, measurement and storage Or geographical data, but instead are in the form of isolated ~ho~ nts from one case to another, hence so far there has been no self-contained~
all-encompassing syste~ for the collection, analysis, measurement and storage of geographical data.
The publication IC~ Te.cb~ica.l Journal, Vol. 6, No. 3, May 1989, Oxford, pages ~42 to 5~6; J.M.P. Quinn: "...Towards Geographic Information System," provides a solutiom, according to which available data is o-~n~ t~-to a conventional database, whereby a combination of the measured data with the spatial data is achieved, whereby th~ vector~data is ob.tained frQm the picture data.
The disadvan~age Qf thi~ solution is, among other things, that the accomodation Qf =
* Air picture vertic~l recording * satellite supported plotting and * satellite r~vigatiDn data * stereoscopic observation * radar plotting * microwaves * scans * aerial triangulation is not possible.
To overcome the aforementioned disadvantages of the prior art, it is the object of the invention to develop a method for the ~ 21 91 954 Wo 9S/33973 . ~ PCT~D~ 95/00639 collection, analysis, measurement and storage o~ geographical data that guarantee5 practical data handling and simplified availability in large, medium-sized and small user centers, and that allows optimization of existing C~ UJI~I~LS in dlgital stereo work stations with interactive superposition, fitting in and continuation o~ digitally collected landscape, planning, or real property data or land records maps, and with supplementary alphanumeric information~
The engineer, pro~essional worker or operator should be given the opportunity to observe the planning area either two-dimensionally or even three-dimensionally on the screen, depending on the e~uipment configuration~ However, he should also be able to call up the digital image information in the form of an orthophotoprojection and superlmposed digital planning or map data on it and adapt it to local conditions According to the invention, this object is attained in accordance with characteristics given in claims 1 and 2. ~he advantages of the invention are extreme savingS of cost and time ~or the collection, analysis, measurement and storage o~ .

~ 21 91 954 Wo 95/33973 PCT/DE 95/00639 geographical data, and are characterized in that the terrain work is done pre~o~in~ntly in the office.
By using satellite-based geodetics for control point measurement (GPS, DGPS~, by using an aircra~t-based data recording of the measurement region with high-precision aerial survey cameras, and by t~n~r~l equipment support via triangulation methods of aerial photogrammetry (use of satellite-based aerial navigation methods), the records or pictures taken exhibit high accuracy with respect to the location of the center of perspective.
Xoreover, with this method, digital image data, graphic data and alrh~ r?ric data are administered ~ointly.
Interfaces to manifold data bases and data formats are available. At the same time, the embodiment has an interface to the currently commercially available GPS receivers, which can be used for ranging or measurement purposes. ~oreover, as needed, the coordinates can be transmitted between the GPS
and the work station by telemetry. Another advantage is considered to be the digitally distortion-corrected image data of the most recent date can be supplied on CD or other data media, thus making aircraft-based data recording, aerial triangulation znd distortion correction by the creator of the CD become superfluous, so that the already existing data stock can be kept current.
Scanning and digitizing of existing land records maps, CAD construction of land records lines, and hybria grid and vector machining on the basis o~ a uniform geodetic reference system are obtained.
Depending on the scope of the uork, the equipment configuration can be adapted successively up to the level of large, high-performance uorkstations. The method provides interfaces to the plotters and scanners available on the market. __ The invention will be described in conjunction with a Fig. 1, which shows the seguence of the method;
a Fig. 2, which shows the instrumental configuration;
and Fig. 3, which schematically ~Ypl~inc the method.
~ he exemplary em~odiment involves a topographic region that is collected, analy2ed, measured and stored by the method.
~ he method shown in Figs. 1 and 2 for collection, analysis, measurement and storage of geographical data includes the stages of object demarcation, data ac~uisition, data processing, data analysis, and data conversion; the ~l~n~.~~ tals of the method are aerial pictures as well as satellite recordings, geodetic information and other plAnn;ng data; in short, three-dimensionally related items of information that are linked together in the object space and processed with the most modern computer and data processing e~uipment configuration. For planning with and using a Geographic Information System, which is what is primarily addressed here, the following method steps are n~r~cq~ry:
1. Geographic demarcation of the project region to be recordea and processed, using existing maps, analog or digital information, or site descriptions.
2. Ac~uisition of geographic or cartesian coordinates, if they are defined in national or supranational grids. In the event that such information is unavailable, then corresponding grids should be prepared, using satellite geodetics with the global positioning system and optionally e~n~n~fl by aerial triangulation.
3. The project region is recorded with high-performance precision aerial survey cameras from the aircraft: the picture material produced must completely cover the region, and it must be assured that observation can be ~ 2 1 9 1 9~4 WO 95/3397~ ~ ~ ~ PCT/DE 95/00639 done stereoscopically. Care must be taken to assure a geodetic inclusion of possible control points selected in the project region.
4. In the event that qualitatively usa'ole satellite image recordings are present, and the later wor~ scale allows the use of the satellite images, then the geographic Pnrorl;ng of the satellite xecoraings must be assured via control points (x, y, z).
~ . ~he method contemplates the possibilities of using inertizl-based D&PS positioning of the camera during the picture-taking flight, in which case the expense for the accomrlichr~nts in paragraph 2 can be reduced.
6. The analog picture material, after being developed, is scanned with high resolution and thus converted into digital information, with a precision in the submicrometer range and with a resolution suitable for the stated ob3 ect.
7. The geographic r~n~n~;ng of the satellite rPcnr~;ngs and aeri~l triangula~tion in position and altitude (x, y, z) make it pncc;hle to survey every individual aerial image molel or the satellite images. ~his procedure is an important provision for incorporating the picture material into the geodetic or geographic grids and hence is a basis for further qualitative measurement and interpretation.
8. On the basis oP the data acquired in paragraph 6, a digital altitude model iB measured or automatically computed, and this in turn is the prereguisite for the difPerential distortion correction of the aerial images~ With the differential distortio~ correction of the digitally available aerial image information, every pixel is in the form of a parallel projection and is thus linked with the subsequent digital image values to produce a digital orthophoto map.
9. By proceeding in steps 1-7, the project region is made availaole to the data user in the form of a digital ~ .

~ 2191954 wo 95/33973 ~C~t~E 95/00639 model in the measuring laboratory ~workstation). Depending on the particular ~rAw~r~ and software ùsed, he has the capability of observing the terrain in parallel projection or three-dimensionally ~plastically) and to measure and plan therein.
The digital terrain information (see method steps 1-8) is stored on suitable data media, with a compass a~forded to the pro~ect region or the intended planning worX. Examples of suitable data media are CDs. These data are offered to potential users, unless a special proiect region is involved, in the usual geographical association for instance on the scale of a country or state, province, district, or community. Thus each user of these digital data has the capability, depending on his experience, instructions or job, Or performing interactive rl~nn~ng or tasking third parties to perform it. This makes consistent construction of surfaces possible by way of lines; points, measurement numbers and mathematical va]ues (such as tracings).
Xoreover, by interpretation, types of use, structural forms, ecological factors, ~n~ , and other elements can be detected at the same time and incorporated into the prepared interactive data stock. In ~urther development, the method also contemplates the three-dimensional incorporation of constructions, for instance in road and bridge building, or in building construction.
lO. ~he interactive construc~ion or planning in the terrain model at the CAD workstation includes the use of additional external, graphic and nongraphic information.
~his requires that the aforementioned information relative to pl~nning be available in the same kind of geodetic or geographic grid that is binding for the terrain model.
ll. ~he information in step lO can al~o be considered a component of the method itself, because it must be produced 21 ql 95~

WO 95/~3973 PCT/DE 95/OOo~9 or ac~uired in a way that fits the course of the method.
~oreover, with existing measurement results from field recordings, mathematically calculated values can be processed in the terrain model at the interactive station. The prerequisite for the linkage of grid and vector information is a uni~orm geodetic reference system.
12. The technical eguipment part of data production contemplates high-perf~7rr-r~ picture-taking aircraft, er~uipped with high-resolution aerial survey cameras, GPS
navigation, ana optionally INS-D&P~ navigation, and moreover makes it possible to ac~uire geographical data and specifically allows the use Or satellite data or aircraft-based sensor systems. ~or further pro~r~q;ng, high-quality photographic laboratories of the usual scope must be used, unless the aircraft-based data recording of the project region is already done digitally at a later time. For high-resolution d7gitizing o~ the panchromatic picture information, suitable scanners are used. Aerial triangulation or other geodetically sa~;cfA~tnry fit point ~r~nr~r~nc~nrJ and the production of digital altitude models are done using high-performance picture processing systems. rrhe storage of the distortion-corrected digital terrain model is aOne with the three-dimensional reference mentioned in paragraph 9.
13. At the same time, taking conventional industrial exchange ~ormats into account, it is assu~ed with the method that the digital picture data, vector data and ~lphAnll~erical information are kept compatible with mani~old data bases and data formats. It is also provided as needed that the data o~
parts thereof be transmitted by telemetry, E-mail, ISDN, and the like, with adequate fees being chargea.
14. The method is oriented to a commercial production strategy aimed at a potentially existing market, and it can : -- ~ 21 9t 954 be modified constantly and adapted as technology progresses.
Basic software for visual display of the in~ormation is included.
In Fig. 3, the method is schematically shown in such a way that a topographical area (region~ 1 is recorded by aerial picture taking by means of aircraft 2, whose location in space is positioned by satellites 3 with the aid of their signals (DGPS), then the digital altitude model 4 in a~o~r~no~ with method step 4 is derived as data ana~ysis or available in calculated form; from the topographical area (region) 1 and the digital altitude model 4, inc~ ;ng the known location of the project centers in space at the time o~
recording by the aircra~t 2/ and by means of mathematical trans~ormation of the analog aerial picture or o~ a digital aerial picture~scene, the digital orthophoto 5 is produced, which is made available to the potential user by means of data media; thus it becomes possible ~or the potential user, depending on his assigned task and requisite decision making, which he, as a customer, has formulated, to add a vector, line graphic 6 to the digital orthophoto 5 and analyze it correspondingly use~ully.

~ 21 91 954 ~O 95/33973 PCT/DE 95/00639 Reference n~mera~s used 1 topographical area tregion) 2 aircraft 3 satellites 4 digital altitude model digital orthophoto 6 vector, line graphic .

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Claims (2)

claims

1. Procedure for the collation, evaluation, measurement and storage of geo-information, whereby the spatial data is linked and processed using a PC and data processor configuration, characterised by the fact that in Step 1 object limiting takes place, e.g. using numerical data, location data, topographical descriptions and geodetic co-ordinates or geographical co-ordinates; that in Step 2 data is procured by means of vertical aerial photographs or satellite-supported records which are stored as aerial mosaics and are then combined to create photographic blocks, if necessary also using information from map materials, and furthermore making use if required of altitude information, satellite and aircraft-supported records in the form of scanner data, terrestrial information (measurements), planning and design data and radar records in the form of multifrequency microwaves in varying polarisations; that in Step 3 data is prepared, which involves taking into account the geo-coded satellite scanner images or vertical aerial photographs, the calculation of the projection centres of the aerial camera and the position of the sensors, the spatial sensor position at the time of the photographs, and data from the DGPS system through the location of the sensors using aerotriangulation; following which in Step 4 data is evaluated, whereby the existing analogue aerial photographs are digitised with a geometric precision in the micrometer range with adapted resolution, which includes activities such as measurement and calculation of a digital altitude model, differential rectification of the digital images in the usual way, the creation of digital aerial photograph blocks (mosaic formation); following which in Step 5 the geo-information from Steps 1 to 4 is reduced in various, industry standard exchange formats for raster data, whereby it is possible to output this on plotters in various resolutions in black-and-white or in colour and to store it digitally on various digital data media such as CD, DAT, STREAMER, digital removable disks, etc. and which is compatible with further databases and data formats and can be exchangedand transferred via telemetry, E-mail and ISDN
Step 6 the data user uses the digital terrain information within the scope of a project or plan as a digital model in the test laboratory by making a consistent construction ofsurfaces using lines, points, measurements and mathematical values, detecting any anomalies by integrating types of use, forms of constructions, ecological factors, so that the terrain work can be carried out in the office and the digital data can be used to draw up a cadaster.

2. Procedure for the collation, evaluation, measurement and storage of geo-information, whereby the spatial data is linked and processed using a PC and data processor configuration in the object space, in accordance with Claim 1, characterised by the fact that a topographical surface (area) (1) is recorded by means of aerial photography from an aircraft (2) whose location in space is recorded using signals (DGPS) from satellites (3); after Step 4, the digital altitude model (4) is available from a derivation or calculation of the data, and, using the topographical surface (area) (1) and the digital altitude model (4) and the known position of the projection centres in space at the time the photograph was taken by the aircraft (2), the digital orthophoto (5) is created by means of mathematical transformation of the analogue aerial photograph or from adigital aerial scene. The digital orthophoto (5) can be placed at the disposal of the user by means of data media, which means that potential users, depending on their given task and the required decision-making which they have formulated as customers, are placed in the position of being able to combine the digital orthophoto (5) with a vector or line graphic (6) and to use this accordingly.