Proceedings with Extended Abstracts (single PDF file) - Radio ...

The signal bandwidth f S in standard ISR applications is typically not narrower than 10 Hz (lowerD-region) or not narrower than about 1000 Hz (E-region). The modulation is usually adapted tocover this bandwidth. We have measured that the bandwidth of ground clutter f C is usually lessthan 0.1 Hz. Thus, the ratio of signal bandwidth and ground clutter bandwidth: Q f = f S / f C > 10.In D- and lower E-region ranges the ratio of signal power P S and clutter power P C:Q P = P S / P C < 0.01Applying a resolution bandwidth f b , adapted to the signal bandwidth f S , can usually lead to majormalfunctions of the analysis, since the ground clutter power will heavily override the signalpower.Usually f C f b ) < f n where f n is the noise bandwidthHowever, the resolution bandwidth f R of any modulation should be adapted to the narrowestbandwidth (i.e., f C ) of the received signals, resulting from the composition of the complex amplitudesa = a S + a C + a n of the IS signal as, the ground clutter a C and the noise a n , in order to optimizethe separation of these three components. In typical ISR applications this would lead to anenormous amount of data to be stored and analyzed, which may be impossible to be performedon-line, even with the fastest computer, since all complex samples of each range gate andinterpulse period would have to be treated. A suitable way around this is the so-called DCsubtractionmethod, which is a standard applied in the MST radar applications.Since f C