An SSR/IFF Environment Model

Recent years have seen increasing pressure on the D band. The SSR/IFF Environment Model (SIEM) is a new software tool which can be used to plan the use of secondary radar frequencies to minimise harmful interference effects. SIEM consists of a suite of programs which can be used to estimate the distribution of interrogations, replies and interference on 1030 MHz and 1090 MHz. Data files describe the interrogators and transponders in a given scenario