The phase statistical characteristic of InSAR image at the isolated point

Current researches on the phase of interferometric Synthetic Aperture Radar (abbreviated as InSAR) images are restricted to the homogeneous scene with spatially constant backscatter coefficients. But in reality, there are many unknown targets or sealers with high backscatter coefficients in the ground scene, which produce several bright spots (called isolated points) in the SAR image. The phase statistical characteristic of interferogram at the isolated point is not available recently. Based on the InSAR system, the phase distribution characteristic of SAR image at the isolated point is analyzed. Furthermore, the interferometric phase probability density function at the isolated point is deduced and the phase statistical characteristic at the isolated point is analyzed in theory which is confirmed by the simulations. Finally the conclusion is obtained that the existence of isolated point can improve the interferometric phase estimation precision which establishes the theoretic foundation for calibrating the InSAR system with the interferometric phase at the sealer.