Wyoming Cloud Radar

    The Wyoming Cloud Radar (WCR) is an observational system for the study of cloud structure and composition. It is installed principally on the Wyoming KingAir , but also on the NSF/NCAR C-130 and in the University of Wyoming Microwave Atmospheric Remote Sensing Mobile Laboratory (MARSF). Operating at 95 GHz (3 mm wavelength), the radar provides high-resolution measurements of reflectivity, velocity and polarization fields. Depending on the antenna configuration used (see Modes section), the scanned plane from the KingAir can be vertical or horizontal, and with two antennas, dual-Doppler analysis is possible. Coupled with the in situ observations of hydrometeors and air motions from the same aircraft these data yield unique information for analysis of cloud and precipitation processes.

   The WCR may be made available to users of the Wyoming KingAir Facility or NSF/NCAR C-130 through the NSF allocation process or by special requests.

   Development of the radar was a joint effort with the Microwave Remote Sensing Laboratory of the University of Massachusetts at Amherst. The WCR was manufactured by ProSensing, Inc. (formerly Quadrant Engineering)

   Major funding for the acquisition, development and research use of the WCR has been derived from The University of Wyoming, NSF, NASA, and ONR

   Chronology of the WCR development

   Collaboration between the Department of Atmospheric Science, University of Wyoming, and the Microwave Remote Sensing Laboratory (MIRSL), University of Massachusetts, to design, develop, install, and apply a millimeter-wavelength airborne radar, began in 1989 with the first field tests of a radar at the UWyo Elk Mountain Observatory. The radar was first mounted on the UWyo King Air research aircraft and operated with the full set of in-situ probes in fall 1992. Following those first tests, evolving versions of the radar have been used in variety of field programs. Through 1994, a radar unit belonging to UMass was utilized in the experiments. By the time of the Small Cumulus Microphysics Study (SCMS), in July 1995, operations began with the radar, hereafter referred to as WCR (Wyoming Cloud Radar), that was purchased by UWyo with funds from NSF, ONR, and the University of Wyoming Office of Research. The radar has dual polarization and Doppler capabilities.

    Since 1995, we participated in a number of field experiments with the WCR mounted on the King Air and in one experiment in which the WCR was mounted on the French research aircraft ARAT. In the summer of 2001 WCR was mounted on the NCAR C-130 and participated in DYCOMSII. WCR was successfully installed on the NRC of Canada Convair-580 for AIRSII, 2003.

    The main advantages of the WCR for cloud and precipitation studies are (i) the essentially instantaneous depiction of reflectivity and velocity fields at high spatial resolution and (ii) the coincident observations of detailed microphysics and of air motions by the other probes carried on the aircraft platform. A variety of cloud systems have been already studied with the WCR, in general revealing cloud structure not seen before. As a colloquial expression, one might say that the use of the WCR in cloud studies is as much of a revolution as was the introduction of the PMS probes in the 1970s.

    Along with the field studies, significant effort at both UMass and UWyo has been devoted to hardware and software improvements in the radar. These include increases in radar sensitivity, increased flexibility in real-time operation, post-flight data quality control, merging radar with KingAir data, and data display and analysis.

    In 2001-2002 three additional antennas, as part of the WCR, were installed in the KingAir. Thus the radar can observe targets in vertical(Up), side (latteral to the aircarft axis), side-forward, near nadir, and down-forward directions. Manual RF switches were used to make 2 of the 4 antennas active at any given time.

    In 2003 a new extension in the use of WCR was accomplished. Under a grant funded by NSF EPSCoR program we built a ground based facility where the WCR and RF radiometers can be operated for the purposes of instrument development, training and research.

    In 2004, a new switch network was built to allow pulse-by-pulse switching of the 4 antennas. This allows the radar to quasi-simultaneously observe clouds in all available directions (except for the slow switch between Side and Up directions). Now the WCR can measure cross sections of a cloud in three dimensions and quasi-simultaneous dual-Doppler analysis in vertical and horizontal planes is possible.

    At the end of 2005 we started discussing the development of a new W-band radar that can replace the current radar. WCR is aging, both, technologically and physically. With WCR2 we plan to bring the latest in digital receiver technology, data acquisition, and improved and more reliable RF design. Higher sensitivity and multi-beam full Doppler spectra are among the expected exciting improvements and new features. The Department of Atmospheric Science is teaming with ProSensing, Inc., Pulse Systems, Inc., and EMS Technologies in the design and the construction of the new radar.

    In early 2007 we finished the design of the radar and in August 2008, ProSensing, Inc. delivered the radar. The radar needed some additional hardware and software work, including a few issues with the W-band modulator built by Pulse Systems. By August 2009 all major issues were resolved and the new radar was tested on the Wyoming King Air. September 2009 the radar was declared operational and available for deployment on the Wyoming King Air and NSF/NCAR C130.

    October 2009. The new radar was installed on the NSF/NCAR C130 for its first deployment during PLOWS 2009-2010 field campaign.

    March 2014. WCR2 has been successfully deployed in 10 field projects so far. A beta version of level 2 (L2) radar products has been developped and distributed to researches working on data from ASCII13 and OWLES14. It is our intent to make L2 processed data a standard product for the coming projects.

    The sponsors of the new WCR2 are The University of Wyoming, NSF, and NASA.

    September 2013. We started working on a major upgrade of the WCR2. We are modifying the W-band antenna switch network to increse the receivers' isolation and improve the close range measurements. Few other modifications to the RF transmitter and the receivers' frontend will be implemented. We are also replacing the existing 12-bit two-channel digital receiver with a 16-bit two-channel digital receiver. New and more powerful data system is also being built that will meet the needs for better polarization and FFT acquisition modes. New parallel-processing system software and better FFT modes are in the work. WCR3 will have a new data format, new radar control and real-time display GUIs,and a new mode configuration tool. WCR2 upgrade is being done in collaboration with ProSensing, Inc.

    We will make maximum efforts to maintain continuity between WCR2 and WCR3 level 1 (L1) and level 2 (L2) products. L2 will become a standard product for the WCR projects after 2015.

    December 2015. The WCR major upgrade is finished and the radar is fully operational.

    The sponsors of the WCR3 are The University of Wyoming and NSF.

    September 2019. UW Atmospheric Science Department is awared Mid-Scale Research Infrastructure grant by NSF. As part of this grant Wyoming Cloud Radar will go through a major upgrade in addition to transitioning from the current UW King Air Research aircraft to a King Air 350 purchased by UW in 2020. The main antenna configuration for WCR4 in the new King Air will be 4 single-pol antennas - 2 pointing near-nadir and about 30 deg forward of nadir, and 2 pointing near zenith and about 30 deg forward of zenith.

    April 2022. WCR4 hardware and system software is nearing completion with expected delivery by September 2022. The upgrade of the W-band transmitter by CPI Canada was finished and the transmitter was delivered to ProSensing in January 2022 for integration with the other hardware. The design of the radar hardware was finished and bench tested. The design of the RF unit re-packaging (for optimal fit in the new UWKA) was also finished and the mechanical parts (mounting plates and support structure) is currently being manufactured. ProSensing is working on the system software and firmware. The full assembly of the radar and ground testing at ProSensing before delivery to UW will take place in June-September of 2022.

    January 2023. WCR4 has been delivered to the University of Wyoming. System software and firmware upgrades are complete including an improved radar control GUI and real-time display. Data products (L0-L2) are now stored in NetCDF-4 (HDF5) CfRadial v2 format, a recently adopted standard for storing radar/lidar data in radial (polar) coordinates. WCR4 is operational and being integrated into the NCAR C-130 and UW Next Gen King Air (expected Oct. 2023). The first deployment will be on the C-130 during CAESAR in northern Sweden, Feb. - Apr. 2024.

    The sponsors of the WCR4 are The University of Wyoming and NSF.