An Investigation of Forest Height Estimation by using TanDEM-X Local InSAR Phase Center Variations

Recent TanDEM-X experiments have shown that forest height can be estimated with single-baseline single polarization interferometric coherences. In this case, an external digital terrain model (DTM), together with the assumption of absence of ground scattering, can be used to obtain a determined inversion problem and height estimates independent of X-band penetration issues even in the densest stands. If a ground DTM is not available, a different way to address the inversion problem in such limited observation space is to parameterize appropriately the vertical reflectivity profile underlying the coherences. In this paper, the use of local phase center height profiles to estimate forest height is investigated and compared to the use of a “mean” lidar profile in terms of the final height estimation performance.