A New Function Expansion for Polarization Coherence Tomography

In this letter, we investigate the polarization coherence tomography technique and propose a new function expansion to reconstruct the vertical profile function. Instead of generating profile in Fourier-Legendre series, we deduce orthogonal functions on [-1, 1] by weight of z², which can increase the highest polynomial order and decrease the condition number of the inversion matrix, indicating that the inversion in the new expansion is more stable and less susceptible to noise. Finally, we apply the technique to simulated dual-baseline data and Chinese X-band single-baseline polarimetric synthetic aperture radar interferometry data to demonstrate its validity and robustness.