Sunny Greetings From Botswana fellow Listers! I have recently acquired some EROS A1 images from central Africa, and have had some problems importing the data into ERM 6.3. I am also a bit disappointed about the final image quality, but this may be a result of bad processing by the data provider.
Okay, here is the story: This is an insurance claim for a mine site which has been overrun by hostile forces. I need to be able to see buildings and large vehciles (mining equipment) basically to see if there is anything left behind at the site. We opted for EROS over IKONOS imagery because of the lower cost and quicker availability of the data. Nominal image resolution for EROS is 1.8 metres, but because the scene was taken off-nadir the actual image resolution is 2.02 metres. Although you cant see cars directly, you should be able to see graders and haul trucks. EROS data is acquired as 11 bits stored in the Least Significant Bits of a 16 bit word. The data were imported into ERDAS Imagine by the satellite tracking station, rectified and exported as a 16 bit Geotiff which I can then import into ERM. The histogram data now looks very odd, as the data range is 0 to 7000 and there is no data in the lower end (zero to 3000). I can then clip the null data and display the image and contrast stretch, but the image looks to be posterised. I have no contrast at the high (bright) pixel values and can't really see any small objects. What I think has happened is the satellite tracking station have flattened the bit depth to 8 bits when importing through ERDAS Imagine, so I have lost a lot of contrast. What I would like to do is import the raw 1A EROS data into ERM to make sure I am not losing anything. Has anyone on the list used EROS data? Thanks much, SRM. Steven R. McMullan, P.Geo. Principal Geophysicist Poseidon Geophysics (Pty) Limited Plot 3423 Matima Crescent Extention 12 Private Bag X018 Gaborone, Botswana Tel +267 351 612 Cell +267 71 300 820 Fax +267 300 787 E-mail [EMAIL PROTECTED] Personal E-mail [EMAIL PROTECTED] ----------------------------------------------------------- To make changes to your subscription, please visit our website, http://www.ermapper.com/technicl/ermapperl/index.htm
