Phase-stability detection of stationary targets

The SAR (synthetic aperture radar) detection of stationary targets hidden in highly cluttered environments by using phase stability is studied. The theoretical performance of such a detection scheme is evaluated using simplified target and clutter models. Detection is based on a model where targets contain a concentration of phase-stable scatterers, and clutter is made up of phase-unstable scatterers. The proposed algorithm involves the transmission of three equally spaced frequencies. Each pixel is characterized by its observed stability, a linear combination of the phase shifts at each of the three frequencies, whose weights are +1, -2, +1, respectively. A mask is a collection of pixels chosen to match the possible geometry of a target. The observed stability of a mask is the weighted average of the squares of the observed stability of the pixels it contains