A Miniaturized Spectrometer Radiometer Based on MMIC Technology for Tropospheric Water Vapor Profiling

Abstract

Abstract-The fabrication of a miniaturized ground-based water vapor profiling radiometer demonstrates the capability of monolithic microwave and millimeter-wave integrated circuit technology to reduce the mass and volume of microwave remote sensing instrumentation and to reduce substantially the necessary operational power consumption and size of the radiofrequency and intermediate-frequency sections. Since those sections comprise much of the mass and volume of current microwave receivers, the fabrication of this system represents an important contribution to the design of microwave radiometers. This miniaturized radiometer implementation is particularly well suited to benefit from the cost savings associated with mass production. The small size of the radiometer (24 × 18 × 16 cm) reduces the power required by the temperature control system and allows a rapid warm-up to the temperature set point as well as maintenance of a highly stable internal temperature. Exhibiting very similar statistical properties, the four channels of the radiometer have measured Allan times of greater than 40 s. Measurement results demonstrate that the instrument achieves a sensitivity of better than 0.2 K for 3 s of integration time. Preliminary comparisons of measured brightness temperatures with simulation results based on radiosonde data show good agreement, which are consistent with previously reported results.Index Terms-Atmospheric measurements, humidity measurement, microwave radiometry, monolithic microwave and millimeter-wave integrated circuits (MMICs), multichip modules (MCMs), remote sensing.

Development and Calibration of a K-Band Ground-Based Hyperspectral Microwave Radiometer for Water Vapor Measurements

“…Total measured brightness temperatures are divided into M groups of τ seconds each, and the Allan variance is one half of the mean square error between contiguous averages brightness temperature (T i ). Allan variance is calculated as [34]:…”

Refractt 2006

“…1) side by side with the commercially available Radiometrics W VP-1500 water vapor and liquid profiler radiometer. The CMR-H measures sky brightness temperatures simultaneously at four frequencies that are chosen for maximum water vapor information content (i.e., 22.12,22.67,23.25, and 24.50 GHz;Iturbide-Sanchez et al 2007). The CMR-H is the first microwave radiometer specifically designed to operate as a node in a coordinated ground-based network for atmospheric observations.…”

Time series analysis of ground-based microwave measurements at K- and V-bands to detect temporal changes in water vapor and temperature profiles

“…In addition to these instruments, microwave radiometers, both ground-based and airborne, operating in the 20-60 and 166-190 GHz ranges are used for the retrieval of water vapor, temperature and liquid water profiles. Ground-based microwave radiometers have been designed, fabricated and used to sense water vapor and temperature profiles from ground to 10 km altitude (Iturbide-Sanchez et al, 2007;Solheim, et al, 1998). Satellite-based instruments like Advanced Microwave Sounding Units (AMSU-A and B) on board NOAA-15 (Susskind et al, 2011;Rosenkranz, 2001) (Rao, et al, 2013) have been used to retrieve humidity and temperature profiles in addition to a range of other parameters.…”