C. SUMMARY OF MISSION REQUIREMENTS 



The recommendations of the Study Team for a FIREX configuration are 

 based upon (1) a tentative understanding of the roles played by wavelength, 

 incidence angle, and polarization in radar imagery, (2) valuable experience 

 gained through both Seasat L-band SAR imagery as well as aircraft L-band, and 

 K-band SAR imagery over various geologic test sites, and (3) the collective 

 judgments of both the Study Team and a much larger radar geology community as 

 discussed for example in the recent Snowmass Report [Snowmass Report, 1979]. 

 The Study Team began with the baseline FIREX mission (C-band, 35°-45°, HH) and 

 developed four increasingly ambitious radar system configurations that were 

 consistent with the radar parameter research issues and applications 

 objectives discussed above. 



The preliminary mission requirements are summarized in Table 4. 



The low-angle mode gives an enhanced sensitivity to topography, where 

 subtle slope changes are depicted with expanded contrast. This region is best 

 for low-lying rough terrain, since layover and compression will severely 

 distort mountainous terrain. 



The intermediate-angle mode, using both like- and cross-polarized data, 

 is at an intermediate angle where sensitivity to topography is minimized and 

 where slope effects can be minimized in studies of rock types and geobotanical 

 anomalies. Furthermore, when taken in combination with the high-angle data 

 mode, 30° convergence stereo pairs would be obtained as a powerful tool in 

 geomorphological studies. 



The high-angle mode is useful for topographic mapping, with no layover 

 and reduced slope distortion and minimal shadowing. 



3-3 



