Three-Dimensional Polarimetric Covariance Matrix Via Insar Histograms: A Case Study With L- And P-Band Nasa Above Campaign Data

We report observations of the three-dimensional polarimetric covariance matrix derived from interferometric synthetic aperture radar (InSAR) histograms. Single-look covariance samples plotted versus InSAR phase are aggregated spatially over a forest patch to form a three-dimensional histogram. To first order, InSAR backscatter histograms resemble lidar waveforms, suggesting that this type of measurement can be used as a proxy for horizontal and vertical tree structure. In this paper, we extend the formulation of the InSAR backscatter histograms to the covariance matrix and discuss possible new applications. Full-polarimetric L-band and P-band UAVSAR (Uninhabited Aerial Vehicle Synthetic Aperture Radar) data collected over Delta Junction in Alaska during the Arctic-Boreal Vulnerability Experiment (ABoVE) are used to illustrate the results. Validation is conducted with the full-waveform LVIS (Laser, Vegetation and Ice Sensor) lidar instrument. Important parameters such as the alpha and the entropy will be extracted along the tree vertical direction and illustrated in the final paper.