These images have a pixel spacing of 500 m at the Equator, and are typically about 1 Mbyte in size. The pixel spacing is exactly 5 times that of the corresponding binary file. They can be displayed by any program that supports the GIF image file format; for instance, Netscape Navigator and Microsoft Internet Explorer support the GIF image format, and will display these files.These images may be found by clicking on "data and image coverage" on the left, where you will find both a clickable image map, and a table listing all the mosaics; or they can be found in the "lowres" subdirectory of the top level "data" folder. The name of each GIF image is "mosaic number".gif (ie. 701.gif).
The sigma0 values may be retrieved from these images. You must have software that can convert the GIF image to the Raw format, or that can display the pixel value (between 0 and 255) (such as Adobe photoshop or NIH image). Then, see the data products information sheet for the conversion formula.
The binary files are located in the "binaries" subdirectory within the top level "data" folder. These files are raw 8 bit images, and have a pixel spacing of 100 meters. Please see the table of mosaic tiles for approximate coordinates for each mosaic tile. They are in the Mercator projection.They are typically about 40 Mbytes in size. In order to display these files, you will have to have a program that supports raw "byte" images, ie. Adobe photoshop or NIH image, and most GIS packages. The name of the binary files are of the form "mosaic number".dat (i.e. 701.dat). In addition, there is a text file called "mosaic number".inf (i.e. 701.inf), that will contain the number of lines and samples of the associated binary file. This information is required for display of the image. There is NO header information within the binary image files. If your computer does not have enough RAM memory, your software might not be able to display the image.
You can find out what image covers your area of interest by browsing the low res GIF images. The coverage may be found by clicking on "browse images" on the left, where you will find both a clickable image map, and a table listing all the mosaics;
To convert values to sigma0, please check the data products information sheet.