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

Abstract

Recent TanDEM-X experiments have shown that forest height can be estimated with the single polarization X-band interferometric coherences. However, an external digital terrain model (DTM) is necessary to retrieve canopy height. Forest height derived from coherence model inversion is known as to be only accurate in certain condition like boreal forest in winter time. In order to overcome these limitations, the use of local phase center variations to estimate forest height isinvestigated. The result over tropical forest shows that the variability of the phase centers helps to estimate height from the oherence. Although the heights are slightly overestimated in low canopy heights area and underestimated dense forests, there is a good correlation with the forest heights obtained from Lidar measurement.