Sar Tomography And Phase Histogram Techniques For Remote Sensing Of Forested Areas: An Experimental Study Based On Tomosense Data

This paper compares two techniques for obtaining forest height and vertical structure from synthetic aperture radar (SAR) data, namely SAR tomography (TomoSAR) and phase histogram (PH). The comparison is carried out on an experimental basis by using the tomographic SAR dataset from the TomoSense campaign, flown by ESA in 2020/21 to support investigation of forested area for future low frequency spaceborne SAR missions. Both techniques were tested using data at full and degraded resolution. Experimental results show that the PH technique can only loosely approximate the forest vertical structure produced by SAR tomography, although it was able to achieve a fairly good estimate of forest height if the appropriate range of height of ambiguity is used. A degraded performance of the PH technique when applied to low-resolution data indicates that this technique is best fit for the case of high-resolution data, consistently with the assumption of the presence of dominant scatterers. Overall, these findings indicate the PH technique as an interesting option in the context of high-resolution spaceborne missions.