NASA SBIR 2004 Solicitation


PROPOSAL NUMBER: 04 E1.05-8345
SUBTOPIC TITLE: Active Microwave
PROPOSAL TITLE: A Low-Sidelobe Frequency-Scan Millimeter-Wave Antenna for Cloud and Precipitation Sensing

SMALL BUSINESS CONCERN (Name, E-mail, Mail Address, City/State/Zip, Phone)
Remote Sensing Solutions, Inc.
P.O. Box 1092
Barnstable, MA 02630-0001

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
James R Carswell
P.O. Box 1092
Barnstable, MA 02630-0001

NASA is committed to measuring clouds on a global scale and will soon launch CloudSat, which will carry the first space borne cloud-profiling radar (CPR). Operating at 94 GHz, the CPR will conduct a 2 year global survey of cloud properties, collecting quantitative information on cloud-layer thickness, base and top altitudes, cloud optical thickness, and cloud water and ice contents. A follow-on mission is envisioned that will fly a low-mass cross-track scanning antenna. This will provide future missions with much improved spatial coverage for comparison with numeric models and reduced time between subsequent measurements over the same region.

This proposed Phase I effort will investigate the required innovations to design and build a novel airborne prototype W-band (94 GHz) cross-track scanning antenna and wideband radar system. The proposed antenna will utilize a low-mass offset reflector and a frequency-scanned line-feed to achieve for the first time at W-band a cross track scan width of approximately 60 degrees. This design will lead to a prototype scanning radar system that can be flown on high-altitude platforms such as the NASA ER-2, WB-57 and Proteus. The prototype antenna will be compatible with existing space-qualified transmitters and can be scaled for space flight.

The proposed electronically scanning W-band antenna and airborne scanning cloud radar will support various NASA research efforts by facilitating three-dimensional cloud radar coverage over a much larger domain than can be measured with existing nadir-pointing cloud radars. These data can be combined with those colleted simultaneously by scanning radiometric instruments to facilitate cloud microphysical retrievals over a large domain. Once proven these measurements can ultimately be collected on a global scale by flying the scanning radar on the next generation cloud sensing satellite.

The proposed antenna system can be adapted for a variety of uses. Coupled with a high power transmitter and sensitive receiver it is an ideal tool for quantifying cloud properties. Such high performance radar has obvious applications for high-resolution tracking and target detection. The lightweight-scanning antenna feed may also be used in conjunction with inexpensive low power transmitters for high-resolution object detection over short distances such as in vehicle collision avoidance systems. RSS plans to aggressively pursue these opportunities