Scanning Precipitation Radar Data Corrected and Standardized in New Evaluation Product

Published: 18 February 2013

cmac — a) Attenuation corrected reflectivity filtered for second trip returns. b) Rainfall rates calculated from specific attenuation. Click to enlarge.

Raw moments from the scanning ARM precipitation radars (SAPRs) are subject to a number of instrument and atmospheric phenomena that must be retrieved and corrected for. The Corrected Moments in Antenna Coordinates (CMAC) value-added product contains both raw data and fields that have been processed to:

correct for velocity aliasing
unfold and generate a cross-polarimetric phase difference that is monotonically increasing, removing impulses caused by non-uniform beam filling and phase shift on backscatter
recalculate specific differential phase using a 20-point Sobel filter on the aforementioned phase
correct for liquid path attenuation using the polarimetric signals
estimate rainfall rates at the gate using the specific attenuation.

In addition, CMAC writes the data out into a community-standard format netCDF File using the CF/Radial conventions. The data are therefore compatible with new and existing National Center for Atmospheric Research (NCAR) tools such as RadXConvert for converting to a variety of popular file formats.

More information on CMAC is available at the VAP web page and in the README file that accompanies the data files in the Data Archive’s evaluation area.

To access these data, log in to the Data Archive. (Go here to request an account.)

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The ARM Climate Research Facility is a DOE Office of Science user facility. The ARM Facility is operated by nine DOE national laboratories, including .