Various SDTS Raster Transfers Provided by ERDAS Incorporated

Released: 6 June 1996 (README updated 26 October 1998)

The following images are provided by ERDAS, incorporated, to exercise
some of the capabilities of SDTS Raster Profile, including:

	Multi-spectral Data (GI and GL Encoding)
	Integer and Floating Point Data
	Pseudocolor (Thematic) Data
	Georeferenced Data, including some level 2 projections

These images are fairly small as the focus is on the structure, rather
than the contents, of SDTS Raster Profile transfers.  These transfers
were produced using a development version of the SDTS Raster Profile
encoder that is now available with Imagine 8.3 and later.  The content
and form of these transfers should be considered preliminary and
subject to change.  Some verification of the contents has been done by
manual examination and by running the development version of the
decoder.  Comments about the structure or contents of these transfers
are welcome and would be appreciated, given the limited means of
verification currently available.  Please direct technical comments or
inquiries to Miles Duke (duke@erdas.com).  For information regarding
availability and features of ERDAS software, please contact Ian
Anderson (ianderson@erdas.com).  The phone number is (404) 248-9000.

LakeLanierGA/HNGL*.DDF - Upper Lanier
	16-bit (see Note 1) unsigned integer, athematic from Landsat TM
	Image Size: 135 x 186, 7 bands, Layer Interleaved by Pixel (GL)
	Data Range: Min(56), Mean(67.1), Max(151)
	Map Boundaries (Edge): UL (283820, 3800215), LR (237870, 3805795)
	Pixel Size: 30 meters
	Projection: Level 1, UTM
	Datum: NAD 27

GainesvilleGA/BEDR*.DDF - Lower Lanier (Gainesville)
	16-bit (see Note 1) unsigned integer, athematic from Landsat TM
	Image Size: 181 x 185, 7 bands, Layer Sequential (GI)
	Data Range: Min(53), Mean(76.7), Max(255)
	Map Boundaries (Edge): UL (237270, 3794665), LR (242700, 3800215)
	Pixel Size: 30 meters
	Projection: Level 1, UTM
	Datum: NAD 27

LanierGA-Soils/INSL*.DDF - Lanier Soils Survey
	16-bit (see Note 1) unsigned integer, thematic classification
	Image Size: 296 x 371, 1 band
	Data Range: Min(2), Mean(25.8), Max(35)
	Map Boundaries (Edge): UL (233820, 3794665), LR (242700, 3805795)
	Pixel Size: 30 meters
	Projection: Level 1, UTM
	Datum: NAD 27
	
RadarSite/OUTH*.DDF - Radar
	32 bit floating point, athematic from a radar image
	Image Size: 150 x 150, 1 grayscale band
	Data Range: Min (36.429), Mean (1944.262), Max (20648) -- (See Note 4)
	Map Boundaries (contrived): UL (226000m, 430000m), LR (229000m, 433000m)
	Pixel Size: 20 meters
	Projection: Level 2, Lambert Conformal Conic (see Note 2)
	Datum: WGS 72
	Latitude of 1st standard parallel: 45 degrees north
	Latitude of 2nd standard parallel: 35 degrees north
	Longitude of central meridian: 60 degrees east
	Latitude of origin: 0 degrees
	False Easting: 50,000 km
	False Northing: 50,000 km

2 of the 3 Lanier images are subsets of a Landsat TM image of the
Gainesville, Georgia area including Lake Lanier.  The third is a
thematic classification of the soils in the area.  The Lanier images
are registered to the Earth's surface using the Universal Transverse
Mercator projection and the NAD 27 Datum.  The right-most 20 pixels on
the bottom edge of the Lake Lanier dataset abut the left-most 20
pixels of the top edge of the Gainesville dataset.  In other words, if
you view both images in the same map coordinate system, the image
edges will be in contact for a distance including 20 pixels, with no
overlap and no gap between the placement of the two images.  The soil
survey is the smallest rectangle containing both of the TM datasets.

Technical Notes

(1) These 8-bit images have been padded to 16 bits, due to a problem
with the 1.0.3 version of the FIPS library supplied by the USGS.  The
1.0.4 version of the FIPS library addresses these problems, so padding
is no longer necessary.

(2) The radar image is encoded with a level 2 projection,
with the parameters encoded according to a private agreement based
upon GCTP.  For details on that private agreement, see the "GCTP" file
in the RadarSite directory.

(3) The map boundaries in these images are specified in the Spatial
Domain (SPDM) module, rather than the Internal Spatial Reference
(IREF) module.  Later experience has shown that the IREF module is the
location intended by the USGS for this information.

(4) The SDTS Dump utility (and other tools) may interpret these
floating-point numbers as long integers, which yields numbers in the
billions.  Oddly enough, such numbers do form a visible image, but
they do not reflect the original image quantities.

(5) All of these transfers were built following an older draft
of the SDTS Raster Profile.