User Manual - pancroma

IMPORTANT NOTE: There is a check box option on the dialog box that allowsthe user to display the subsetted band and panchromatic files or not. If yoursubset area is a relatively large percentage of the base image size, and/or yourcomputing power is not great, you should uncheck this box. This will allow theprocessing of larger files before a possible ‘out of memory’ error occurs.PANCROMA will automatically detect the corner coordinates for GeoTiffLandsat, SPOT and ASTER files and Landsat L1G input files. The UTM latitudeand longitude coordinates, as well as the row and column values will be reportedto the Main Window as the cursor tracks across the image. Knowing the cornercoordinates of your subsetted images is often necessary for subsequent uses ofthe cropped Landsat images. Note that the UTM zone and hemispheredesignation is reported at the bottom of the Main Window.If you want to enter the pixel coordinates of the upper left and lower right cornersof the subset area, click the ‘Select by Pixel’ radio button. Then use your mouseto locate these numbers on the Landsat image that is presented to you. Justclick on the corners and the corresponding pixel coordinates will be entered intothe text fields in the dialog box. If you make a mistake, just keep clicking.PANCROMA TM will allow you as many tries as you need. When you are satisfiedthat you have entered the correct coordinates, select the’ Accept Pixel Entries’and then select the ‘Enter’ button on the dialog box. (As you click on the corners,the latitude and longitude will also be entered into the text box fieldsautomatically.) The subset band images will be computed and displayed uponclicking ‘Enter’.If you want to key in the coordinates, select the ‘Select by Coordinates’ radiobutton. The coordinate data entry boxes will be enabled, allowing you to enteryour desired upper left and lower right coordinates. If you make a mistake andenter a coordinate value outside the image extents, the offending latitude orlongitude will default to the closest boundary coordinate.IMPORTANT NOTE: The UTM coordinates for the Southern Hemisphere arereported using Landsat convention, which is different from the UTM standard.The UTM standard assigns a false northing of 10,000,000 meters at the equator,decreasing the latitude value as one moves toward the South Pole. Landsatconvention assigns zero meters at the equator (the same as for the NorthernHemisphere). Southern Hemisphere latitudes are all negative, decreasing invalue (becoming more negative) as one moves south towards the pole. In orderto convert from one convention to the other, add the Landsat latitude to10,000,000.IMPORTANT NOTE: if you have left the ‘Display Subset Images’ box checked,the images will be displayed when you save the file.39