Reply Path Side Lobe Suppression (RSLS)
A second possibility of the side lobe suppression can be carried out on the replay path. Reply path Side Lobe Suppression (RSLS) enables replies received in the antenna side lobes to be rejected. (A lot of of these replies are interferences, so called „Fruit”.) In addition you need the following equipment to this:
- a second, identically constructed receiver channel, and
- a comparator.
The principle is the amplitude comparison again of two signals which are received about different antenna characteristics here, too. All reply impulses are received about the two antenna systems and fed in in two identical receive channels. Since the processing is same in the two channels, the difference measured by the different antennae patterns remains unchanged.
The amplitudes of the both video signals are compared with each other about comparator circuits and only the desired signal is reprocessed. This additional wiring has the advantage that also larger demanded arguments can be adjusted in the amplitudes as this 9 dB of the ISLS. This often is importantly to suppress the effects of disturbing reflections of area objects near the SSR site.