ates (as 
nown ob- 
1 occasio- 
proach for 
articular 
6 teooresult, 
ich 1s 
could be 
yund control 
for this 
' calibra- 
ind tedious. 
ry and dis- 
s in 
ctive 
a great 
or LFC 
Yo 
the con- 
ment etc. 
tation of 
in the pro- 
ods, pro- 
nly applied 
Cc investi- 
has been 
image 
nts are 
sformation 
ordinates 
cise 
ially 
   
  
Fig. 3.1: 
Approximate situation of 
Martificial ground contol points 
& (circles = corner refelctors, 
triangles = ARCS and compact 
i@receivers) in a SIR-B image 
“(processed by DFVLR WT-DA) 
scale 1 : 500 000) 
~~ ~~ 
4. Radar Maps and Radar Orthophotos 
  
4.1 Quicklook results 
The proposed SAR image standard product is ground range imagery. These data 
might be sufficient for 
- oceanographic purposes (imagery without GCPs) and 
- for users in coastal areas and in flat terrain. 
Fig. 4.1 shows an overlay of a spaceborne ground range image (courtesy 
JPL/Pasadena) with contour lines (approximate scale 1 : 500 000). The Topo- 
graphic Analysis System Hannover (TASH) was applied to plot a part of the 
50 m-DEM data with a 50 m contour interval. The contour lines have been 
appoximated by a 5th order spline function 
  
   
Fig. 4.1: Combination of a radar ground range image and contour lines 
(scale about 1 : 500 000) 
4.2 Radar orthophoto 
For tasks which require map accuracy (usually about + 1 ... 3 pixels, see 
DOYLE (1975) and KONECNY ef al. (19034 by, 
- mosaiking 
- multisensor imagery and 
- change detection 
a digital geometric pixel by pixel image restitution is needed, preferably 
applying the indirect rectification method, which is just in an improving 
phase, see Fig. 4.3. 
To handle larger output image blocks and to calculate for regional or 
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