On the benefits of space-time adaptive processing in FM ranging airborne radar

Frequency modulated interrupted continuous wave (FMICW) waveforms can be used to resolve range ambiguities in pulse-Doppler airborne radar operation. The approach is usually associated with high pulse repetition frequency (PRF) modes where ambiguity resolution by means of PRF scheduling can be difficult. However, FMICW modes can broaden the Doppler bandwidth of clutter and therefore lead to reduced target detectability in clutter limited applications. This paper considers the implications of employing space-time adaptive processing (STAP) for clutter suppression in FMICW modes. It is shown that STAP can potentially provide benefits, but a planar array antenna, offering adaptive degrees of freedom in elevation and azimuth, is ideally required.