ISIS Documentation

makeflat

Create a flat-field image for line-scan instruments

This program creates flat-field images for line scan, push frame, and framing instruments. All input cubes should have the same number of samples; any images in the list that do not have the same number of samples as the first image will not be used. The names of the cube files used to create the flat-field image must be entered using an ASCII file (FROMLIST) with one filename per line (any line beginning with a '#' or '//' is treated as a comment). The specific equation for each camera type is below.

  • Line Scan

    • A frame is a NUMLINES line section of data. The equation for the final single line, single band, flat field file is:
    Sum( Sum(FrameColumn) / Average(Frame) * ValidPixels(FrameColumn) ) / TotalColumnValidPixels

  • Push Frame

    • The equation for the final single framelet, single band flat field file is:
    Average( PixelInFramelet1, PixelInFramelet2, PixelInFramelet3, ... )

  • Framing

    • The equation for the final single framelet, single band flat field file is:
    Average( PixelInCube1, PixelInCube2, PixelInCube3, ... )

Warning: This program creates potentially large temporary files

Categories

History

Tracie Sucharski2007-06-20 Original version, Adapted from Isis2 version of makeflat.
Steven Lambright2008-05-13 Removed references to CubeInfo .
Steven Lambright2008-06-11 Changed algorithm and added support for framing and push frame cameras.
Ian Humphrey2014-06-23 Cleaned up spacing in pushframe test Makefile