A Low-Cost Laboratory-Based Polarimetric Synthetic Aperture Radar System for Scattering Analysis [Education Corner]
The scattering mechanisms captured using polarimetric synthetic aperture radar (PolSAR) imaging enable applications like target detection and image classification. This article presents PolSAR images from a unique low-cost, laboratory-based imaging system that captures the basic scattering mechanisms using radar calibration targets, such as a flat plate and dihedral and trihedral corner reflectors. The characterization of the basic scattering mechanisms with good ground truth information is important for classification with PolSAR imagery and for modeling polarimetric signatures. The PolSAR instrument is calibrated using a corner reflector, and the calibration is then validated using an independent data set. The calibration is done in terms of radar cross section (RCS) in decibels referenced to a square meter (dBsm). Results show the system is capable of capturing the basic scattering mechanisms of the single and double bounce. Validation results of the calibration process are off by about 3 dBsm and 4.5 dBsm from the theoretical values of the RCS for the vertical transmit-vertical receive (VV) and horizontal transmit-horizontal receive (HH) channel calibration, respectively. This is acceptable for a low-cost system capable of differentiating scattering mechanisms. This PolSAR system can be used for experimentation within the laboratory for phenomenology studies.