Then simulations have shown that the resolution broadening of pixel averaging can be well approximated by . As shown in figure 4 this is a good approximation for range as well as for azimuth where also the antenna pattern influences resolution. While the sidelobe structure is still visible in the first case, it is gone in the second case. The dominant influence on calibration accuracy is expected to be caused by the roll angle uncertainity of the shuttle. To accommodate for roll angle drift the radiometric correction function is updated in 1 sec intervals.
Incidence angle is accounted for by using the reference Earth ellipsoid.
Since not all of the many instrument modes can be supported by these measurements, it is necessary to generalize the inversion of the radar equation factor CS . Processing filters are normalized to unity white noise gains, their signal gains, however, will be computed from the actual azimuth antenna pattern. The algorithmic core of the X-SAR processor has been finished, tested, and accepted in December 1992. 50 km azimuth extent. PRF-Ambiguity Resolving by Wavelength Diversity, IEEE Trans.