This OLYMPEX DOW Version-1 dataset was active from 31 October 2017 through 1 August 2018, and has now been retired.
The new version is now available at

The GPM Ground Validation Doppler on Wheels (DOW) OLYMPEX dataset was obtained by a dual-polarization and dual-frequency X-band mobile radar operated by the Center for Severe Weather Research (CSWR) during the Olympic Mountain Experiment (OLYMPEX) campaign. The DOW was deployed in the Chehalis Valley for the OLYMPEX field campaign with the goal of obtaining radar reflectivity observations of precipitation in order to better understand the orographic enhancement of precipitation during frontal passages over mountain ranges. The DOW radar uses two 250 kW transmitters with a measurement range of roughly 60 km. CF-Radial data files are available from 06 November 2015 to 15 January 2016 in the netCDF-4 file format. There is 1 radar volume per file representing 10 minutes of data.

The new version of DOW OLYMPEX data was created due to a discrepancy between DOW and the NASA S-Band Dual Polarimetric Doppler radar (NPOL), which was also used in the OLYMPEX field campaign. A new and more appropriate calibration method was determined and the data were reprocessed.

To cite the entire DOW Version-1 data (available from October 31, 2017 through August 1, 2018), please use the following:

Houze, Robert A.. 2017. GPM Ground Validation Doppler on Wheels (DOW) OLYMPEX [indicate subset used]. Dataset available online from the NASA Global Hydrology Center DAAC, Huntsville, Alabama, U.S.A. 

For more information on GHRC DAAC citations, see these Instructions for citing GHRC data.

General Characteristics

Publication date: 2017-10-31
Retirement date: 2018-08-01
Version: 1
Collections: GPM Ground Validation Products
Projects: OLYMPEX
Instruments: DOW
Terms: Radar
Processing level: 2
Format: netCDF-4


[coverage map]
Red dots or areas indicate coverage range.


Location: Washington
Spatial resolution: 60 km
North boundary: 48.0271°
West boundary: -124.408°
East boundary: -123.331°
South boundary: 46.9499°
Temporal resolution: 1 minute - <1 hour
Start date: 2015-11-06 13:34:26
Stop date: 2016-01-15 22:39:15


Retired Dataset: Retired data available on request only
User's Guide:
The guide document contains detailed information about the dataset
General Documentation:
About the DOWs Center for Severe Weather Research
General Documentation:
Doppler On Wheels (DOW) Earth Observing Laboratory
The Olympic Mountains Experiment (OLYMPEX)
Project Home Page:
View Related Information:
University of Washington OLYMPEX Web Site
Digital Object Identifier
Collection DOI:
OLYMPEX Field Campaign Collection DOI
Instructions for citing GHRC data.


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