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This data set includes non-Doppler polar volume reflectivity data from the Baltic Sea Experiment (BALTEX). Data were collected on Sweden's Gotland Island, using an Ericsson radar mounted at 56 m above sea level. The radar provided 12 scanning angles. Measurements were taken between 1 September 2002 and 31 May 2003. BALTEX data sets will be used for validation of AMSR-E and Advanced Microwave Sounding Unit (AMSU)/Humidity Sounder for Brazil (HSB) Level 1 brightness temperatures and Level 2 cloud and precipitation parameters. Data are available in network Common Data Format (netCDF) from NSIDC via FTP.
The Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) is a mission instrument launched aboard NASA's Aqua Satellite on 4 May 2002. The Baltic Sea Experiment's (BALTEX) Radar Data Centre (BRDC), operated by the Swedish Meteorological and Hydrological Institute (SMHI), collects data from as many radars in or near the Baltic region as possible. During the Main Observational Phase (October 1999 - February 2002), data from 25 radars in six countries covered the Baltic region every 15 minutes. High-latitude data are recorded from 50 to 70 ° North, and they complement pre-existing efforts in the mid-latitudes and tropics.
Bennartz, R. 2004. Baltic Sea Experiment (BALTEX) Ground-Based Radar Polar Volume Data. [indicate subset used]. Boulder, Colorado USA: NASA National Snow and Ice Data Center Distributed Active Archive Center. doi: 10.5067/FVJJ6961HB7L.
|Spatial coverage and resolution||57.24°N, 18.39°E|
|Temporal coverage and resolution||1 September 2002 to 31 May, 2003, in 15-minute intervals|
|Tools for accessing data||Use an appropriate application to view netCDF data|
|File naming convention||File strings describe file contents, including the radar, place, date, and time|
|File size||2.3 MB|
|Procedures for obtaining data||Data are available via FTP and HTTPS.|
University of Wisconsin-Madison
Swedish Meteorological and Hydrological Institute
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Data are provided in netCDF format. The netCDF headers contain dimensions, units, and other information.
There is a tar file on the FTP site for each month data were collected.
File strings describe file contents, including the non-doppler radar (znp), place, date, and time. For instance, the file "znp_hem_030531t0145.h5.nc" indicates that the data were collected from Hemse radar station at 1 hour 45 minutes in UTC on 31 May 31 2003.
Each data file is 2.3 MB.
1 September 2002 to 31 May, 2003.
Data are given in 15-minute intervals.
The parameter measured in this data set is reflectivity.
The following table shows the scanning angle for the 12 scans in each data file.
(elevation angle in degrees)
Reflectivity is given in dBz.
The measurements were taken from the Gotland Island Hemse radar station.
The following shows scan 1 of the data file "znp_hem_030519t1145.h5.nc."
Data files are contained in compressed tar files, one file for each month. The total compressed volume is 212 MB.
Use an appropriate application to view netCDF data.
The netCDF format is an interface for array-oriented data access with an interface library. The netCDF library also defines a machine-independent format for representing scientific data. Together, the interface, library, and format support creating, accessing, and sharing scientific data. The netCDF software was developed at the Unidata Program Center in Boulder, Colorado. More information about netCDF and software for manipulating and displaying NetCDF is available from Unidata.
The following table provides information about the Hemse radar station, the instrument, and data acquisition.
|Radar System||Ericsson EWR Radar|
|Location||Gotland Island (57.24 ° North, 18.39 ° East), Sweden|
|Processing Software||Ericsson Enterprise Wireless Internet Solutions (EWIS)|
|Height of the antenna||56 m above sea level|
|Distance between two successive range bins||2,000 m|
|Number of range bins in each ray||120 (with 2,000 m spacing)|
|Number of azimuth gates (rays) per scan||480 (starting North, clockwise)|
|Half-power beamwidth||0.9 °|
|Antenna speed in revolutions per minute||6|
|Pulse width||2 ms|
|Low-pulse repetition frequency||250 Hz|
|High-pulse repetition frequency||250 Hz|
|How raw data in range are processed to arrive at the given value||average|
The following acronyms and abbreviations are used in this document.
|AMSR-E||Advanced Microwave Scanning Radiometer - Earth Observing System|
|AMSU||Advanced Microwave Sounding Unit|
|BALTEX||Baltic Sea Experiment|
|BRDC||BALTEX Radar Data Centre|
|EWIS||Enterprise Wireless Internet Solutions|
|FTP||File Transfer Protocol|
|HSB||Humidity Sounder for Brazil|
|netCDF||Network Common Data Format|
|SMHI||Swedish Meteorological and Hydrological Institute|