Washita '92 Data

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Image files for Estar, soil moisture, soil texture and NDVI data are 228 pixels by 93 lines with a pixel resolution of 200m by 200m. The UTM coordinates of the corners are:

         563844 E                             609444 E                        3872666 N                            3872666 N          +--------------------------------------+          |                                      |          |                                      |          |                                      |          |                                      |          |                                      |          +--------------------------------------+          563844 E                             609444 E         3854066 N                            3854066 N 

The data is stored in 1 byte format, that is, each pixel is stored as one byte in the files.

ESTAR image data

This data set is based on the ESTAR microwave data.

The number in the file name corresponds to the day in June, 1992 that the data was collected. To convert to Brightness Temperature in Kelvin, add 70 to the digital number.

• June 10, 1992
• June 11, 1992
• June 12, 1992
• June 13, 1992
• June 14, 1992
• June 16, 1992
• June 17, 1992
• June 18, 1992

Soil Moisture Images

The number in the file name corresponds to the day in June, 1992 that the data was collected. The digital number corresponds to the percentage of soil moisture.

• June 10, 1992
• June 11, 1992
• June 12, 1992
• June 13, 1992
• June 14, 1992
• June 16, 1992
• June 17, 1992
• June 18, 1992

LandUse Data

Landuse data

This data set is a modification of the MIADS ftp://hydrolab.arsusda.gov/pub/wash92. The landuse image is classified as follows:

          DN    Classification          1    Rangeland         2    Cropland         3    Pasture       4    Forest       5    All others 

Soil Texture Data

Soil Texture data

This data set is a modification of the MIADS database.

The soil texture data is classified as follows:

     DN    Classification          1    Sand             2    Loamy Fine Sand            3    Fine Sandy Loam         4    Loam         5    Silt Loam         6    Silty Clay Loam / Clay Loam         7    Pits, Quarries, Urban         8    Gypsum         9    Water   

Classified NDVI Data

Classified NDVI data

NDVI calculated from a SPOT image aquired July 9, 1992. The equations used to calculate the NDVI are as follows:

          DN         ------       = L Spectral radiance           a          L * pi        ----------    = R  Aparent reflectance         E * cos(Tz)         a       = (1.051 for RED and 1.1796 for NIR)          E       = spectral irraciance for particular bandpass                    = (1626.98 for RED and 1076.35 for NIR)      cos(Tz) = cos of solar zenith angle (0.94 for both RED and NIR)  

Calculate the aparent reflectance of the NIR & RED channels

Rnir = (NIR * 2.98914620) /(1529.36120)

Rred = (RED * 2.66326946) / (1011.76900)

Then compute NDVI, scaling to an 8 bit unsigned integer

NDVI = ((Rnir - Rred) /(Rnir + Rred)) * 255;