Time-averaged subspace methods for radar clutter texture retrieval

Subspace approaches have become popular in the last two decades for retriev ing constant amplitude harmonies observed in white additive noise because t hey may exhibit superior resolution over the FFT-based methods, especially with short data records and closely spaced harmonies. We demonstrate here t hat MUSIC and ESPRIT methods can also be applied when the harmonics are cor rupted by white or wideband multiplicative noise. The application context i s the retrieval of texture information from high resolution and low grazing angle radar clutter data affected by wideband colored speckle that is mode led as complex multiplicative noise. Texture information is fundamental for clutter cancellation and constant false alarm rate (CFAR) radar detection. A thorough numerical analysis compares the two subspace methods and valida tes the theoretical findings.