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GPM Ground Validation Micro Rain Radar (MRR) GCPEx V2 (EC MRR and NASA MRR) Table of Contents
The GPM Ground Validation Micro Rain Radar (MRR) GCPEx datasets were collected during the GPM Cold-season Precipitation Experiment (GCPEx) in Ontario, Canada during the winter season of 2011 - 2012. Two separate MRR instruments were used during the campaign; five MRR instruments were operated by Environmental Canada (EC) and three were operated by NASA. Operating at 24 GHz, the MRR is a vertically pointing Doppler radar which derives quantitative rain rates, drop size distributions, radar reflectivity and fall velocities on vertical profiles up to several kilometers above the unit. Version 2 of these datasets became active on April 30, 2015; the original data (raw spectra format) was converted to netCDF format by the University of Wisconsin. CitationThe following examples show how to cite the use of these datasets in a publication. For more information, please see our Citing GHRC DAAC and Data page. EC:
NASA: Campaign The GPM Cold-season Precipitation Experiment (GCPEx) occurred in Ontario, Canada during the winter season of 2011-2012. GCPEx addressed shortcomings in the GPM snowfall retrieval algorithm by collecting microphysical properties, associated remote sensing observations, and coordinated model simulations of precipitating snow. These data sets were collected to aid in the achievement of the over arching goal of GCPEx which is to characterize the ability of multi-frequency active and passive microwave sensors to detect and estimate falling snow. During GCPEx, an MRR was located at each of the five sites in Ontario, Canada. The site names and locations for the Environmental Canada MRR and the NASA MRR are listed below. EC:
NASA:
The NASA MRR deployed at the Huronia site experienced a component failure soon after deployment, and thus no usable MRR data was collected at this site during the campaign. Further details on GCPEx are available at http://gpm.nsstc.nasa.gov/gcpex. Information on the Global Precipitation Measurement (GPM) mission is available at http://pmm.nasa.gov/GPM. Additional campaign collections containing MRR data can be found at http://ghrc.nsstc.nasa.gov. Instrument DescriptionThe EC MRR is a frequency-modulated continuous wave (FMCW) vertically pointing Doppler radar, which operates at 24.24GHz. The MRR measures profiles of Doppler spectra and derives drop size distributions, rain rates, and liquid water rates. The MRR is the second generation of the instrument manufactured by METEK. Additional information is available at http://metek.de/product/mrr-2/. *EC Disclaimer: Please note that the CARE and Steamshow MRRs used version 5 software and the Skydive, Huronia, and Morton MRRs used version 6 software. *NASA Disclaimer: Since the derived fields (e.g., attenuation, radar reflectivity, rain rate, liquid water content) in level 1 and 2 data assume rain and no vertical wind, caution should be used when using these derived fields if any snow may have been falling or in the presence of strong vertical motions (Peters et al. 2005). Attenuation correction is only performed for PIA less than or equal to 10 dB (Peters et al. 2010). InvestigatorsEC: David Hudak Mark Kulie Claire Pettersen NASA: Walter A. Petersen Patrick Gatlin Mark Kulie Claire Pettersen The EC MRR files are named with the following convention:
The NASA MRR files are named with the following convention:
where, Data Format The GPM Ground Validation MRR datasets consist of daily netCDF files for each campaign site. It should be noted that this is the second version of the data. Original GCPEx MRR data was published in the text format (ave) from the MRR company, however the ave data and raw data are not well documented. The University of Wisconsin reprocessed the MRR datasets and converted the raw spectra data to netCDF format after verifying the original format of the data. The Maahn algorithm was used to convert the snow cases, and the netCDF conversion was completed using the Maahn method documented by Maahn and Kollias. *Disclaimer: Because of the conversion methods used, this data should be used assuming mostly snow. VersionThe MRR GCPEx datasets were originally published as: EC:
NASA: References Mahhn, M. and P. Kollias, 2012: Improved Micro Rain Radar snow measurements using Doppler spectra post-processing. Atmos. Meas. Tech., 5, 2661-2673. doi: http://dx.doi.org/10.5194/amt-5-2661-2012 Peters, Gerhard, Bernd Fischer, Hans Munster, Marco Clemens, Andreas Wagner, 2005: Profiles of Raindrop Size Distributions as Retrieved by Microrain Radars. J. Appl. Meteor., 44, 1930-1949. Peters, Gerhard, Bernd Fischer, Marco Clemens, 2010: Rain Attenuation of Radar Echoes Considering Finite-Range Resolution and Using Drop Size
Distributions. J. Atmos. Oceanic Technol., 27, 829–842. To order these data or for further information, please contact:
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