NASA SBIR 2003 Solicitation


PROPOSAL NUMBER: 03- II E1.04-7642
SUBTOPIC TITLE: Passive Microwave
PROPOSAL TITLE: Electronic Correlated Noise Calibration Standard for Interferometric and Polarimetric Microwave Radiometers

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Kazem F Sabet
1340 Eisenhower Place
Ann Arbor, MI 48108-3282
U.S. Citizen or Legal Resident: Yes

A new type of calibration standard is proposed which produces a pair of microwave noise signals to aid in the characterization and calibration of correlating radiometers. The proposed Correlated Noise Calibration Standard (CNCS) is able to generate pairs of broad bandwidth stochastic noise signals with a wide variety of statistical properties. The CNCS can be used with synthetic aperture interferometers to generate specific visibility functions. It can be used with fully polarimetric radiometers to generate specific 3rd and 4th Stokes parameters of brightness temperature. It can also be used with spectrometers to generate specific power spectra and autocorrelations. It is possible to combine these features and, for example, generate the pair of signals that would be measured by a fully polarimetric, spectrally resolving, synthetic aperture radiometer at a particular pair of polarizations and antenna baselines for a specified scene over a specified frequency band. The proposed CNCS will cover all the frequencies used for radiometric observations in the 1 to 40 GHz range. In specific, the Phase II project will develop the system prototypes for L and X bands. While intended for ground based characterization of radiometer systems, the technological approach is amenable to on-orbit calibration.

Aerospace corporations, Universities, government agencies other than NASA, and international groups also construct correlating radiometers that will benefit from this technology. Indeed, correlating radiometer technology developed by NASA will increasingly be exploited by other institutions; especially as enabling technologies like the CNCS are developed. Those institutions known to the authors to manufacture radiometers include, but are not limited to, Boeing, Northrop Grumman, Ball Aerospace, Aerojet, Quadrant Engineering, U. S. Navy, NOAA ETL, The University of Michigan and The University of Massachusetts.

NASA is seeking correlated noise calibration devices for use in numerous microwave correlating radiometer systems (such as synthetic aperture interferometers, polarimetric radiometers, correlating spectrometers, and instruments utilizing any combination of these techniques) now under development or being proposed. Systems that could benefit from this technology include, but are not limited to, Conical Scanning Microwave Imager/Sounder (CMIS), Lightweight Rainfall Radiometer (LRR), Geosynchronous Synthetic Thinned Aperture Radiometer (GeoSTAR), ACMR, etc.