A Scanning FMCW W-Band Radar for Cloud and Fog Research
Abstract
This proposal seeks DURIP funding to acquire a Frequency Modulated Continuous Wave (FMCW) W-band radar for research involving atmospheric water droplets (hydrometeors; e.g., fog, clouds and rain). Hydrometeors cover a range of sizes, and radars operating at different frequency bands are used for their observations. For instance, Ka (~35 GHz) and W (~94 GHz) band radars operating at millimeter-wavelength are employed to observe cloud microphysical processes, measure the velocity structure, estimate rain rates, obtain distribution of small cloud particles from non-precipitating or weakly precipitating clouds, and retrieve information on incloud turbulence. Where higher sensitivity is needed and the size and weight of the instrument are not a factor, Ka band radars that require larger antennas are used. Where instrument compactness and weight are a limiting factor, such as deployment on a research vessel with the radar resting on a motion compensated platform, W-band is the radar of choice for hydrometeor research. Recent advent of a new generation of user-friendly commercial FMCW W-band radars has enabled researchers and observatories to engage in hygrometric research without facing onerous infrastructure and maintenance challenges. The radar requested in this proposal, the FMCW Wband cloud Doppler radar (model RPG-FMCW-94-DP-G1/S) manufactured by Radiometer Physics GmbH (RPG), is of this type. It is a dual polarization, single frequency turnkey system provided with an elevation/azimuth scanner designed for cloud and fog research. These radars measure small water droplets of millimeter and submillimeter scales (? 10 ????) enabling retrieval of useful quantities such as reflectivity, mean radial velocity, spectrum width, skewness and kurtosis for characterization of atmospheric water droplets. Its compactness, low power (severalWatts), agility, and high space-time resolution (~ 1m spatial and integration times of seconds) allow characterization of small cloud drops and ice particles, fog, liquid and solid precipitation, and even non-meteorological scatterers such as insects and pollen. This off-the-shelf instrument comes with a comprehensive, adaptive software interface. The versatility of the instrument can be significantly enhanced by operating it alongside other available instruments to the PI such as Doppler lidars and microwave radiometers. It is the pioneering commercial W-band radar of its kind, extensively field tested, and currently used by several European observatories. It will greatly add to the atmospheric instrumentation capabilities of University of Notre Dame, thus enhancing PIs ability to characterize fog and clouds in two Office of Naval Research funded large international projects and in other existing and future federally funded projects. Close collaboration with Department of Defense (DOD) and non-DOD laboratories and universities is a hallmark of the PIs projects, and thus a wider scientific constituency will benefit from the acquisition of proposed instrument.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 20, 2019
- Source ID
- N000141912588
Entities
People
- Harindra Fernando
Organizations
- Office of Naval Research
- United States Navy
- University of Notre Dame