frew@hub.ucsb.edu (Jim Frew) (04/01/88)
EOSAT (the U.S. consortium that operates the Landsat satellites) has recently made Landsat imagery available on floppy disks. In response to the numerous requests in this newsgroup for ready-made digital images, I am posting the following abstract of an announcement from the December 1987 issue of Landsat Data User Notes: EOSAT is offering 512 x 512 pixel windows of Thematic Mapper data on 5.25" floppy disks in MS-DOS format. Six sample scenes are available from the EOSAT Customer Services Dept.: Morro Bay, CA Colorado River, AZ New Orleans, LA Mississippi River, TN Black Hills, SD Bakersfield, CA Each scene consists of 7 diskettes (1 band per disk). Price $250 per scene, "available for a limited time." Price $600 for arbitrary scenes from the EOSAT library, specified by lat-lon of the center point. Contact: USGS EROS Data Center (Sioux Falls, SD: 1-800-367-2801) or EOSAT HQ (Lanham, MD: 1-800-344-9933) FYI (for those unfamiliar with Landsat Thematic Mapper): The Thematic Mapper is a 7-channel scanning radiometer (swinging mirror + solid-state detectors) on board the Landsat-4 and Landsat-5 satellites. Each pixel corresponds to approximately 30x30 meters at the Earth's surface. A full TM scene is about 5000x6000 pixels (x7 bands == over 200 Mbytes) and costs several thousand dollars, so the floppy format is a relative bargain. The channels are: channel wavelengths (nm) notes 1 450-520 blue 2 520-600 green 3 630-690 red 4 760-900 near-infrared 5 1550-1750 "shortwave infrared" 7 2080-2350 "shortwave infrared" 6 10.4 um - 12.5 um thermal infrared Channels 1,2,3 give you something approximating true color (quite bluish due to atmospheric scattering). Channels 2,3,4 give you the traditional "false-color infrared" (vegetation looks red). Channels 5 and 7 are new critters for spaceborne sensing (for example, snow and ice are BLACK in these wavelengths). Channel 6 has 120 meter resolution and is registered to the other channels by replicating each pixel into a 2x2 box. I use TM data in my own research and would be happy to correspond with anyone wishing more information about this stuff. No, I am not associated with EOSAT, except as an occasional customer. -- #----------------------------------------------------------------------------- # James Frew (805)961-8413 frew@hub.ucsb.edu # CSL, UCSB, Santa Barbara, CA 93106 ucbvax!ucsbcsl!frew