Data Set ID:

SMEX02 Aircraft Polarimetric Scanning Radiometer (PSR) Data, Version 1

This data set includes brightness temperature (Tb) and soil moisture data.

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Geographic Coverage

  • Microwave > Brightness Temperature
  • Soils > Soil Moisture/Water Content
Spatial Coverage:
N: 42.732, 
S: 41.694, 
E: -93.161, 
W: -93.841
Spatial Resolution: Not Specified
Temporal Coverage:
  • 25 June 2002 to 12 July 2002
Temporal Resolution: Not specified
Data Format(s):
  • ASCII Text
Platform(s) AIRCRAFT
Sensor(s): PSR
Version: V1
Data Contributor(s): Thomas Jackson, Rajat Bindlish, Albin Gasiewski, Marian Klein, Eni Njoku

Data Citation

As a condition of using these data, you must cite the use of this data set using the following citation. For more information, see our Use and Copyright Web page.

Bindlish, R. and T. Jackson. 2002. SMEX02 Aircraft Polarimetric Scanning Radiometer (PSR) Data, Version 1. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. doi: [Date Accessed].

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Detailed Data Description


Data are provided in ASCII text format.

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File and Directory Structure

The main directories are regional and watershed, for the two different regions studied. Subdirectories under each of these are gridded and ungridded. The gridded directory contains brightness temperatures. Within the gridded directory is the sm directory, which contains the estimated soil moisture based on the PSR observations. The ungridded directory contains the raw brightness temperature observations.

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File Naming Convention

Gridded files have names such as "IA629.txt" and "WC629.txt." The two-letter prefix indicates the area (IA=regional, WC=Walnut Creek watershed), followed by the month and day. 

Ungridded files use the same convention as above, with the addition of a letter A-D, which designates the number of times (1-4) the flight line was flown that day.

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File Size

File sizes range 267 KB to 4.31 MB.

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Total volume of data files is 195.15 MB.

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Spatial Coverage

Southernmost Latitude: 41.694°N
Northernmost Latitude: 42.732°N
Westernmost Longitude: 93.841°W
Easternmost Longitude: 93.161°W

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Temporal Coverage

This study was conducted 25 June through 12 July 2002.

Temporal Resolution

Flights took place on June 25, 27, 29 and July 1, 4, 8, 9, 10, 11, and 12 of 2002. All six flight lines were flown every day.

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Parameter or Variable

Parameter Description

The first two columns in the data columns are the UTM (northing and easting) and the next four columns are the brightness temperatures: C-band (7.32 GHz) (V and H) and X-Band (10.7 GHz) (V and H) observations, respectively. The files in the sm directory have the UTM location followed by the estimated soil moisture.

Sample Data Record

The following is a sample from the watershed gridded data table "WC627.txt."

435685.00 4648265.00 286.60 278.17 284.91 279.16
435685.00 4648065.00 288.28 279.96 287.29 281.20
435685.00 4647865.00 290.35 281.95 290.68 285.93
435685.00 4647665.00 0.00 0.00 0.00 0.00
435685.00 4647465.00 291.95 283.68 293.42 288.32

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Software and Tools

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Data Acquisition and Processing

Sensor or Instrument Description

The PSR/CX instrument was integrated onto the NASA WFF P3B aircraft in the aft portion of the bomb bay. The PSR scans at a constant incidence angle of 45°. In SMEX02, PSR was flown over the watershed and regional areas. There were four regional flight lines at an altitude of ~8000 m. Two watershed lines at an altitude of ~1500 m covered the Walnut Creek watershed area. Flights took place on June 25, 27, 29 and July 1, 4, 8, 9, 10, 11, and 12 of 2002. All six flight lines were flown every day.

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References and Related Publications

Contacts and Acknowledgments

Thomas J. Jackson and Rajat Bindlish 
ARS USDA Hydrology and Remote Sensing Lab 
Albin J. Gasiewski, Marian Klein
Eni Njoku Jet Propulsion Laboratory

Document Information


May 2004

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