A Ka-band Interferometer for Cryospheric Applications-Instrument Description and First Results

Characterization of the Earth´s oceanic and cryospheric topography is among NASA´s strategic goals for the next decade. An effective technique for achieving such measurements is radar interferometry. For this technology, use of mm-wave frequencies (Ku- and Ka-band) is appealing due to the proportional size of the space borne structure to the observing wavelength and minimal snow penetration. At such high frequencies, achieving stability in instrument performance and the mechanical deployment structure for accurate measurements is an engineering challenge. To address this, the Microwave Remote Sensing Laboratory at the University of Massachusetts is developing a high performance Ku- and Ka-band interferometer as a prototype for a space borne instrument. The interferometer will be used in a scaled-down ground-based configuration. This paper presents an instrument description of the Ka-band interferometer (the down-converter in particular) and first results from its performance evaluation.