This OLYMPEX APR-3 Version-1 dataset was active from 20 June 2017 to 20 July 2018, and has now been retired.
The new version is now available at

The GPM Ground Validation Airborne Precipitation Radar 3rd Generation (APR-3) OLYMPEX dataset was collected from November 12, 2015 to December 19, 2015 during the GPM Ground Validation Olympic Mountains Experiment (OLYMPEX) field campaign held in the Pacific Northwest. This first version of the dataset was published in June 2017. It was replaced by an updated version [DOI:] in June 2018. The APR-3 is an updated version of the APR-2 instrument used in previous field campaigns, and contains an additional W-band measurement capability. APR-3 scans cross-track from +/- 25° to the right and left of nadir. During OLYMPEX, Ku-band, Ka-band and W-band frequency doppler measurements were made from the DC-8 aircraft at 10km altitude. The APR-3 dataset files are in HDF-4 format with PNG format browse images. This L1 APR-3 Version-1 dataset provided radar reflectivity, doppler velocity for all bands, linear depolarization ratio at Ku-band, and normalized radar cross section measurements at Ka and Ku-bands. For improved data now available in HDF5 format, we direct users to obtain the APR-3 Version-2 dataset [DOI:].

This APR3 dataset was intended for research and users should contact the APR-3 team regarding data use, especially before publication or public presentation. This dataset has been superceeded by the APR-3 Version-2 dataset [DOI:]. All users are invited to address questions and provide feedback to the Data Provider.

To cite the entire APR3 Version-1 data (available from June 2017 to June 2018), please use the following:

Durden, Stephen L. and Simone Tanelli. 2017. GPM Ground Validation Airborne Precipitation Radar 3rd Generation (APR-3) OLYMPEX [indicate subset used]. Dataset available online from the NASA Global Hydrology Center DAAC, Huntsville, Alabama, U.S.A. DOI:

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

General Characteristics

Publication date: 2017-06-20
Retirement date: 2018-07-20
Version: 2.3
Scientific release: 1
Collections: GPM Ground Validation Products
Projects: OLYMPEX
Platforms: NASA DC-8
Instruments: APR-3
Terms: Radar
Processing level: 1B
Format: HDF-4


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


Location: Washington
Spatial resolution: 800 m horizontal resolution at 10 km altitude, 60 m range resolution
North boundary: 49.3347°
West boundary: -129.048°
East boundary: -122.134°
South boundary: 45.9626°
Temporal resolution: 1 minute - <1 hour
Start date: 2015-11-12 16:21:07
Stop date: 2015-12-19 03:21:09


Retired Dataset: Retired data available on request only
User's Guide:
The guide document contains detailed information about the dataset
Development of an advanced airborne precipitation radar
Simultaneous Measurements of Ku- and Ka-band Sea Surface Cross-Sections by an Airborne Radar
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.

Sample Browse Image

Sample Browse Image



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