Instrument Trade Study Final Report Advanced Microwave Radiometry and Scatterometry

• Main Authors: Eni G. Njoku, Bill Wilson, Simon Yueh, Yahya Rahmat-samii
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1998
• Subjects: Sea ice
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.499.344; http://esto.nasa.gov/files/1999/Njoku.pdf

Microwave radiometry and scatterometry are preferred techniques for many remote sensing applications, particularly for measurements of soil moisture, snow cover, sea ice extent and motion, sea surface salinity, sea surface temperature, and sea surface wind velocity. Achieving a given spatial resolution for these measurements requires much larger effective apertures at microwave frequencies than at optical and infrared frequencies. It is thus a challenge, for low-frequency microwave systems, to achieve high spatial resolution within necessary limits on payload size and cost. In this study we have examined techniques and technology options for achieving desired microwave system performance (high spatial resolution and accuracy) using low-mass deployable antennas. We have focused on soil moisture and ocean salinity, as science applications of high priority that drive the requirement for large antennas, and cannot at present be measured adequately from space. System and subsystem performance requirements have been defined, traceable to the science requirements for these parameters, in order to establish detailed technology targets, and to enable planning and prioritization, for a potential space mission. For soil moisture and salinity sensing, the desired frequencies are in the range 1 to 3 GHz, and