Abstract: For the detection and suppression of interfering signals in SAR data, a time-domain noisy raw data signal U.sub.T (t) is Fourier-transformed by range lines in raw frequency-domain spectrum U.sub.T (f). The resulting spectrum U.sub.T (f) is law-pass filtered according to a transmission-signal bandwith B.sub.s to yield a useful spectrum U.sub.T (f) and an autocorrelation function (t) of useful spectrum U.sub.T (f) is determined in the time domain. A weighting function w(t) is used to suppress portions of the useful signal in the autocorrelation function (t), thereby intensifying the interfering signal in relation to the autocorrelation function (t). The resulting signal (t) is transformed into a power spectral density (f) and a threshold value m is calculated from the power spectral density (f) with a MADMED function. A final notch filter W.sub.N (f) is generated by Fourier-transforming the ideal notch filter frequency response W.sub.N ideal (f).

Abstract: In a method of synchronizing navigation measurement data according to the invention, first radar data are evaluated by means of the reflectivity-offset method, by means of which the aircraft deviation in the antenna viewing direction is determined. The aircraft deviation in this direction is also determined from the outputs of a navigation system. The temporal courses of the two obtained deviations are cross-correlated. The position of the cross-correlation maximum is determined, and indicates the temporal offset between two associated deviation signals. The radar data are delayed by this amount of time, so synchronization is effected between navigation measurement data and radar data. An optimum compensation of the motion errors can be effected with the synchronized data. The invention can be used in on-board aircraft SAR systems.