Photogrammetry and Remote Sensing |
Suite | Reconstruction
procedure | Examples |
Quide map, Petra
The orthophoto and respective DEM. The KVR-1000 images used for this
orthophoto date back to year 2000.
Digital Elevation Model (DEM)
The DEM was produced by Sovinformsputnik with application called Z-Space.
It is presented here as a gray value image, where dark areas represent
wadis and light areas mountains. The estimated accuracy of the Z-values
is ± 11.7 m and was calculated using 14 points.
Software for the application Z-Space has been developed by State Research
Institute of Aviation Systems, Moscow, Russia.
|Image file format:
|Image file name:
|Image file size:
|Number of columns:
|Number of rows:
|Image Corner Coordinates (Lat/Lon):
||UpperLeft: 30:21:35.680N 35:22:12.194E
|Map Coord. Units:
||UL: 3361049.59332 (Northings) 727788.8559 (Eastings)
Geometric terrain modelling
The Digital Elevation Models (DEM) are produced from
TK-350 stereo-pairs by Sovinformsputnik. The
standard posting (grid step) of DEM produced is 20 m.
Every four successive TK-350 frames form stereo-pairs
between each other, and forelap px of adjacent stereo-pairs differs by
Geometric quality B/H of these stereo-pairs is:
B/H = 1.03 (px = 20%, Px = 56.8 km)
B/H = 0.77 (px = 40%, Px = 113.6 km)
B/H = 0.52 (px = 60%, Px = 170.4 km)
B/H = 0.26 (px = 80%, Px = 227.2 km)
The process of creation includes following
This final DEM serves as a basis for production of
simulated three dimensional (3D) terrain models.
production of stereoscopic terrain model on a basis
of TK-350 stereo-pairs
spatial geodetic orientation of this model resulting
in production of Geometric Terrain Model
creation of uncorrected Digital Elevation Model
editing, correction and accuracy control of DEM.
On-board equipment incorporating two star-trackers
(stellar cameras), precision laser altimeter and positioning system, allow
to determine TK-350 angle orientation elements with 10-15’’ accuracy, altitude
with about 5 m accuracy and distance with 20 m accuracy.
With no additional ground control
RMS error in plane +/- 20 m
RMS error in height +/- 10 m.
With additional GPS supply (coordinates and outlines
of GPS points are to be provided by the customer) significantly increases
(required density of additional GPS points is 1 point per 1500 sq. km):
RMS error in plane +/- 10 m
RMS error in height +/- 4-5 m.
DEMs are utilized by a growing number of mapping
authorities for production of 1:50.000 scale topographic maps with a contour
interval 10 meters. Cellular telephone companies are also depending on
the unusual accuracy of the DEMs for helping to develop realistic radio
frequency propagation models. Companies that specialize in production of
three dimensional (3D) databases for flight simulation and various entertainment
software packages are using the DEMs merged with 2-meter resolution KVR-1000
data for generation of highly realistic perspective views.
Available file formats: ASCII, Generic Binary.
Media: CD-ROM, 4 mm DAT; 8 mm EXABYTE (UNIX
tar or Windows NT Backup).
V. Tchekalin and M. Fomtchenko,1997. GIM magazine, Vol. 4/97
Return to the page: "Research
at the HUT Institute of Photogrammetry and Remote Sensing"
Return to the home page of HUT Institute
of Photogrammetry and Remote Sensing