Roman Arbiol
artefacts and visual discrimination of small textures. The quantitative tests check for the real number of /ooks, the
radiometric resolution, spatial resolution, contents of the speckle associated with the radar images, etc.
The geometric control of the digital products is made using the ground control point measurements done during the field
campaign. The points have been observed on the images and a comparison with the ground measurements has been
done. Due to the poor image coherence near the water bodies a few points has been rejected but final result shows a very
good geometric confidence. The planimetric test using 24 points shows a circular RMS error of 8.8 m. The altimetric
test using 31 points shows a RMS error of 5.7 m.
7 CONCLUSIONS
The most important conclusion is that single pass airborne interferometry is a reliable and operational tool for mapping
missions in areas with severe cloud cover. Having become accustomed to the long stand-by of photographic missions in
this type of area, the performance of the radar flights is a very pleasant surprise, even though some days can be lost due
to excessively dense cloud cover or turbulence.
On the other hand, a long period of time is required to process the radar data. This is due not only to the considerable
computations, but also to the trial-and-error type of process mentioned earlier. Comparatively, the amount of hardware
needed and time spent are several times greater than for an equivalent optical mission. Fortunately, the intensive
computer-bound processes run in batch on a configuration that is easily scalable.
REFERENCES
Lira, J. (1999): Calidad de una imagen radar. Personal communication.
Moreira, J. 1996. Airborne SAR: image generation and height precision DEM generation. In: International Archives of
Photogrammetry and Remote Sensing, Vienna, Austria, Vol. XXXI, Part B2, Commission II: 256-260, 1996.
28 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part Bl. Amsterdam 2000.
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