idb is the instrument header database produced by the Field Tape Reader. It contains all the header parameters of all the images copied during the field tape reader processing stage. Each header parameter is a separate record and they appear in the same order as do the parameters within the image headers. The number of header parameters may vary from image to image, but all of the header information from any image appears as adjacent records within the idb. The order of the images in the idb is the same as the order of images within the field tape copy tape and the rhd.
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