These data are quadrangle mosaics of the six Landsat 7 ETM+ nonthermal bands that have been 
corrected for atmospheric scattering, and overlapping scenes adjusted to match adjacent scenes, 
so that the data form a seamless data set throughout Afghanistan.  Anomalous reflectance values
in snow/ice and clouds were corrected; scan line reflectance anomalies were also corrected. 

The scenes were mosaicked into the map quadrangles with 100 pixels of overlap
on all sides.  All quadrangles are projected in UTM (WGS84) in their appropriate zones.  The 
original 28.5-m resolution of the 6 bands was enhanced to 14.25-m resolution using the panchromatic
image data that was "noise removed."

The reflectance values were originally 16-bit values.  In order to make the data useable to a
wide array of applications and users, we converted the 16-bit values to 8-bit values by multiplying the
16-bit reflectance values by 0.0255 (or 255/10,000); each 8-bit value represents 0.39% reflectance.
To derive the original reflectance values, simply multiply the 8-bit values by the ratio (10,000/255).

	
Band numbers consists of 1 through 5 and 7.  Band 6 is the thermal infrared band and is not 
included in these data because it is rarely useful.

Band Number 	Center wavelength (microns)

	1		0.48
	2		0.57
	3		0.66
	4		0.84
	5		1.65
	7		2.22

Each map quadrangle is 1 degree of latitude by 2 degrees of longitude.  The numbers assigned to 
each map quadrangle refer to the latitude, longitude coordinates of the lower left corner of 
the quadrangle.  Thus, quadrangle Q2960 has its lower left corner at 29 degrees North latitude and 
60 degrees East longitude.

The locations of the Landsat quadrangle mosaics are shown in the "landsat etm+ mosaic footprints.jpg"
on the DVD.