Title: Wide-swath Shared-aperture Cloud Radar(WiSCR)
Presenting Author: Lihua Li
Organization: NASA GSFC

Abstract:
Wide-swath Shared-aperture Cloud Radar (WiSCR) Lihua Li1, Peter A. Stenger2, Paul E. Racette1, Gerald M. Heymsfield1, Michael E. Cooley2, Thomas Spence2, Richard E Park2, Matthew McLinden1 1NASA Goddard Space Flight Center 2Northrop Grumman Electronic Systems The primary objective of this ESTO IIP-2013 project is to advance key enabling technologies for the next generation spaceborne cloud and precipitation radar. The Earth Science Decadal Survey (DS) Aerosol, Cloud and Ecosystems (ACE) mission calls for a dual-frequency cloud radar (W band 94 GHz and Ka-band 35 GHz) for geospatial measurements of cloud microphysical properties. Meanwhile, a tri-frequency spaceborne radar concept (W band 94 GHz, Ka-band 35 GHz, and Ku-band 14 GHz) is being considered by the cloud and precipitation science communities. Advancing a Wide-swath Shared-aperture Cloud Radar (WiSCR) will provide unprecedented, simultaneous multi-frequency measurements to enhance understanding of the effects of clouds and precipitation and their interaction on Earth climate change. Through extensive key technology studies applied to the Ka-Band TR module design and a W-band subscale antenna airborne demonstration, we have successfully shown the technical feasibility of a shared, large aperture antenna to achieve wide swath imaging at Ka-band and nadir profiling at W-band during the previous ESTO IIP-2010 study. Over this IIP-2013 performance period, we will mature technologies for WiSCR by (1) investigating architectures that extend our dual-band aperture technologies to provide tri-frequency shared aperture capability; (2) advancing the development of the Ka band AESA T/R module including the GaN power amplifier MMIC, the GaAs multi-function and low noise amplifier MMICs, the Power Controller/Gate Regulator ASIC, and the integrated transmit/receive circulator; (3) development of a novel Frequency Diversity Pulse Pair (FDPP) technique for spaceborne Doppler measurements, advancing the technology readiness of Field-programmable Gate Array (FPGA) based Multi-channel Arbitrary Waveform Generator (MAWG) and compact Multi-channel Frequency Conversion Module (MFCM). This presentation will give an overview of the project rationale, technical objectives, and recent progress.