Data Set ID:

SMEX03 Aircraft Polarimetric Scanning Radiometer (PSR) Data, Alabama, Version 1

The Polarimetric Scanning Radiometer (PSR) is an airborne microwave imaging radiometer developed and operated by the National Oceanic and Atmospheric Administration (NOAA) Environmental Technology Laboratory. This data set includes brightness temperature data for the C-band and X-band.

This is the most recent version of these data.

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Data Format(s):
  • ASCII Text
Spatial Coverage:
N: 35.19, 
S: 34.66, 
E: -85.77, 
W: -87.09
Spatial Resolution:
  • 800 m x 800 m
Temporal Coverage:
  • 25 June 2003 to 17 July 2003
Temporal ResolutionNot specifiedMetadata XML:View Metadata Record
Data Contributor(s):Thomas Jackson, Rajat Bindlish, Albin Gasiewski, Marian Klein, Boba Stankov

Geographic Coverage

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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.

Jackson, T., R. Bindlish, A. J. Gasiewski, M. Klein, and B. Stankov. 2007. SMEX03 Aircraft Polarimetric Scanning Radiometer (PSR) Data, Alabama, 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 as ASCII text files. Table 1 describes the format of the processed data files. Table 2 describes the format of the raw data files.

Table 1: Column Descriptions for Processed Data Files



Column 1 UTM - Northing
Column 2 UTM - Easting
Column 3 C-band (7.32 GHz) V
Column 4 C-band (7.32 GHz) H
Column 5 X-band (10.7 GHz) H

Table 2: Column Descriptions for Raw Data Files



Column 1 UTM - Northing
Column 2 UTM - Easting
Column 3 Latitude
Column 4 Longitude
Column 5 C-band (7.32 GHz) V
Column 6 C-band (7.32 GHz) H
Column 7 X-band (10.7 GHz) H
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File and Directory Structure

Data are organized in directories based on study area (AL = Alabama, GA = Georgia, LW = Little Washita, ON = Oklahoma North, OS = Oklahoma South). Within each study area directory are a processed and a raw directory. The processed directories contain gridded brightness temperatures. The raw directories contain the raw brightness temperature observations.

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File Naming Convention

The processed files are named according to the following convention.



SS = study area (AL=Alabama, GA=Georgia,LW = Little Washita, ON = Oklahoma North, OS = Oklahoma South)
M = month
DD = day

The raw files are named according to the following convention.



PPPP = processing level (L23i)
M = month
DD = day
## = 2 digit number
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File Size

File sizes range from 107 KB to 4.6 MB.

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Total volume of the data is approximately 530 MB.

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Spatial Coverage

Table 3 lists the spatial coverage of each study area. All locations are UTM zone 14 in NAD83/WGS84 datum.

Table 3: Spatial Coverage





Alabama Regional Area

Upper Left 492000 3894600 35.194353404 -87.087877924
Upper Right 612000 3894600 35.188137035 -85.769834626
Lower Right 492000 3837000 34.674943785 -87.087325703
Lower Left 612000 3837000 34.668845602 -85.777562595

Georgia Regional Area

Upper Left 219000 3532200 31.890956391 -83.970846870
Upper Right 219000 3429000 30.961064855 -83.941646829
Lower Right 274200 3429000 30.972927502 -83.364252777
Lower Left 274200 3532200 31.903257457 -83.387736190

Oklahoma Little Washita Watershed

Upper Left 219000 3532200 31.890956391 -83.970846870
Upper Right 219000 3429000 30.961064855 -83.941646829
Lower Right 274200 3429000 30.972927502 -83.364252777
Lower Left 274200 3532200 31.903257457 -83.387736190

Oklahoma North Regional Area

Upper Left 585800 4081000 36.871048244 -98.037331796
Upper Right 641000 4081000 36.864419443 -97.418165280
Lower Right 641000 3997000 36.107428397 -97.433484464
Lower Left 585800 3997000 36.113877589 -98.046657639

Oklahoma South Regional Area

Upper Left 560400 3920100 35.422485463 -98.334661234
Upper Right 618000 3920100 35.417323871 -97.700276141
Lower Right 618000 3812100 34.443677450 -97.715544713
Lower Left 560400 3812100 34.448656578 -98.342479279
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Temporal Coverage

Measurements were collected from 25 June through 17 July 2003 in the study areas. Table 4 lists the collection dates for each area.

Table 4: PSR Collection Dates



Alabama 25, 27, 29, 30 June
2 July
Georgia 25, 29, 30 June
Little Washita 3, 5, 7, 10, 17 July
Oklahoma North 3, 5, 7, 10, 11, 12, 13, 14, 15, 17 July
Oklahoma South 2, 3, 5, 7, 10, 12, 13, 14, 15, 17 July

Data collection was timed to coincide with a 3 hour window centered on the Aqua equatorial overpass time of 13:30 LST.

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Parameter or Variable

Parameter Description

Parameters in this data set are brightness temperatures for the C-band (7.32 GHz) V and H and for the X-band (10.7 GHz) H. Observations at the X-band (10.7 GHz) V are not available due to calibration problems.

Sample Data Record

The following sample shows the first 5 rows from the AL processed file AL625.txt:

492400.00 3837400.00 219.43 162.01 141.87
492400.00 3838200.00 228.56 179.60 170.85
492400.00 3839000.00 244.36 203.46 204.96
492400.00 3839800.00 263.28 230.38 238.26
492400.00 3840600.00 282.41 237.52 260.28

The following sample shows the first 5 rows from the ON raw file L23i70309.txt:

644800.09 3988427.31 36.029610 -97.392853 288.69 280.04 282.86
644817.33 3988714.13 36.032192 -97.392609 0.00 280.38 285.14
644829.49 3989145.96 36.036082 -97.392395 289.11 279.82 284.52
644821.09 3989534.40 36.039584 -97.392417 289.32 280.10 286.49
644796.85 3989932.68 36.043177 -97.392613 289.48 280.16 285.24
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Software and Tools

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Data Acquisition and Processing

Derivation Techniques and Algorithms

Processing Steps

PSR/CX raw data goes through several processing steps. Quality control, time synchronization, calibration, rasterization, and georegistration are considered preprocessing. Following this are removing of Radio Frequency Interference (RFI), adjusting for temporal variations inherent in mapping a large region with an aircraft sensor, and resampling the data to a standard grid that facilitates multitemporal analysis and integration with ancillary data bases for algorithm applications (Jackson et al. 2005).

Grid Resampling

The PSR/CX data consist of beam positions for sequential conical scans. Each beam position footprint is about 3 km in size. Due to sampling rates, the spacing between these footprints is 300 m, which results in over sampling. In addition, each line of data overlaps other lines. In order to produce a data set that can be integrated in further analyses, all the footprint data were used in a kriging-based grid resampling procedure. The output grid selected was 800 m, which matched the nominal field scale in the regions as well as the resolution of other databases. Each channel of data was resampled independently (Jackson et al. 2005).

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Sensor or Instrument Description

The PSR/CX band instrument was integrated onto the NASA Wallops Flight Facility (WFF) P3B aircraft in the aft portion of the bomb bay and flown over the regional and watershed areas. The PSR scans at a constant incidence angle of 55° with a swath width of 19 km. The flight line has a spacing of 11 km and a length of 80 km. Four regional flight lines at an altitude of ~8000 m were flown over AL, GA, ON, and OS. Two watershed flight lines at an altitude of ~3000 m covered the LW watershed area. The P3 was deployed out of Huntsville, Alabama from 25 June to 2 July 2003 and out of Oklahoma City, Oklahoma from 2 July to 17 July 2003.

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References and Related Publications

Contacts and Acknowledgments

Thomas J. Jackson and Rajat Bindlish 
US Department of Agriculture (USDA) - Agricultural Research Service (ARS)
Hydrology and Remote Sensing Lab 
Beltsville, MD 20705

Albin J. Gasiewski and Marian Klein 
University of Colorado at Boulder - National Oceanic & Atmospheric Administration (NOAA)
Center for Environmental Technology (CET)
Boulder, CO 80305

Boba Stankov 
National Oceanic & Atmospheric Administration (NOAA)
Environment Technology Laboratory (ETL)
Boulder, CO 80305 

Document Information

Document Creation Date

November 2007

No technical references available for this data set.

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