An atmospheric water vapor and non-precipitating liquid water profiling system is presented. Included are a review and performance characterization of the hardware, a description with results of the calibration procedure, and experimental confirmation of the profiling system with coincident radiosonde balloon comparisons. The hardware consists of a K-Band (20.5-23.5 GHz) Autocorrelation Radiometer (CORRAD), designed, built, and operated by the Microwave Remote Sensing Laboratory at the University of Massachusetts at Amherst. CORRAD measures the autocorrelation of thermal noise at K-Band generated by water in the atmosphere. The sensor represents a novel approach to microwave remote sensing of the atmosphere with regard to pre-detection bandwidth (3 GHz) and number of equivalent frequency channels (31). The complete system calibration procedure is presented, including frequency resolution (100 MHz) and accuracy, front end system noise debiasing, and absolute gain calibration. An algorithm is developed to recover the atmospheric profiles of water vapor and liquid water from the measured autocorrelation samples. The algorithm uses a constrained minimum squared error estimation procedure on a first order perturbation of the full equation of radiative transfer in the atmosphere. Water vapor lapse rates are estimated with better than $\pm$150 m accuracy. Profile results are in excellent agreement with simultaneous radiosonde balloon soundings by the National Weather Service. A complete system signal-to-noise analysis is performed, from the statistics of the raw data to the uncertainties in the estimated profile. Profile relative uncertainties are 5-10% in the lower troposphere with a 1.0 K standard deviation in the antenna temperature spectrum measurements.
| Identifer | oai:union.ndltd.org:UMASS/oai:scholarworks.umass.edu:dissertations-2590 |
| Date | 01 January 1987 |
| Creators | RUF, CHRISTOPHER STEPHAN |
| Publisher | ScholarWorks@UMass Amherst |
| Source Sets | University of Massachusetts, Amherst |
| Language | English |
| Detected Language | English |
| Type | text |
| Source | Doctoral Dissertations Available from Proquest |
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