Description
Summary:The Microwave Remote Sensing Laboratory (MIRSL) at the University of Massachusetts has developed a 35 GHz stepped FM-CW network analyzer based polarimetric scatterometer for the remote sensing of natural targets. Operation of the system at this frequency is achieved with up conversion and harmonic downconversion. The network analyzer facilitates real time data reduction employing different internal processing techniques. The primary function is to collect polarimetric data of stationary targets such as snow, saline ice and simulated sea ice to characterize the power returned from the target at different states (i.e. rough, smooth, dry, wet, etc.). An indoor facility at the Cold Regions Research Engineering Laboratory (CRREL) in Hanover, New Hampshire allows temperature control, so that data are collected at different growth phases. The system operates over a 2 GHz bandwidth and therefore achieves a range resolution of 7.5 cm. Using the radar range equation, the normalized radar cross section of the ice and snow was computed as a function of incidence angle at different antenna polarizations. During the past year the system was automated and now the angle of incidence, polarization and system temperature are controlled from a remote computer. This winter (1990-1991) snow data at different states were collected at CRREL, and additional saline ice experiments were performed. This time a polarimetric calibration was developed along with a polarization synthesis software implementation to determine polarimetric signatures of the ice.