U.S. Geological Survey home page

AVIRIS Geometric Correction Software

http://speclab.cr.usgs.gov

Below is software to geometrically correct AVIRIS ER-2 roll, pitch, yaw, velocity, scan angle, etc variations. Geometric Corrections to AVIRIS data research paper describing the corrections.

The davinci script derives the required pixel offsets in both line and sample directions. It produces 2 vicar format 16-bit files, one for sample offset and one for line offset in pixels*10 (thus 0.1 pixel resolution). These two files are used as input to a second set of remapp programs that actually do the corrections.

This davinci script has been tested with AVIRIS 1995 data. The data format in some other years may be different and thus this davinci script would need to be modified.

The entire flight line must be processed as one unit. The Engineering_File and Navigation_File are distributed with the AVIRIS data. You must have davinci and gnuplot running to run this script.

command line options:

cmd.davinci.avirisgeom.8 Engineering_File Navigation_File title_for_plots_and_specpr [-plot] [-specpr file_name] [-grid grid_size_in_meters] [-topo height_in_meters]

Example command:

cmd.davinci.avirisgeom.8 file11.fullrun file12.fullrun "Arches Run 3" -plot -grid 16 -specpr spgeom3.sp

uses files 11 and 12 from the aviris tape distribution, makes plots of all parameters, makes a specpr file (spgeom3.sp) of the resulting data, and sets the output pixel grid spacing to 16 meters.

The two vicar pixel offset files generated by the davinci script are: line.offset.10.v and sample.offset.10.v


cmd.davinci.avirisgeom.8 davinci script program (original)
cmd.davinci.avirisgeom.9 davinci script program (new Jan 10, 2001)

Next, the remapp program avrecgen is run:

Avrecgen generates two absolute offset lookup images from the preceding two relative lookup images (scanline and pixel). These lookup images are generated only once. They may then be used to rectify many images having the same AVIRIS base coordinates.

Example command:
avrecgen
line.offset.10.v (input image)
0 0 0 0
0 0 0
sample.offset.10.v (input image)
0 0 0 0
0 0 0
scanline_absolute_offset (output image)
pixel_absolute_offset (output image)

Next, the remapp program avrectfy is run:

Avrectfy rectifies any AVIRIS based image or mineral map using the two (above) generated absolute lookup images and outputs the final rectified image.

Example command:
avrectfy
image_to_rectify (input image)
0 0 0 0
0 0 0
scanline_absolute_offset (input image)
0 0 0 0
0 0 0
pixel_absolute_offset (input image)
0 0 0 0
0 0 0
rectified_output_image (output image)

To install these programs, get the remapp software and install it first, then compile these with the remapp library.


avrecgen.f Fortran program
avrectfy.f Fortran program


Speclab Home Page Speclab Contents/Index

U.S. Geological Survey, a bureau of the U.S. Department of the Interior
This page URL= http://speclab.cr.usgs.gov/aviris.geom.software/avgeom.html
This page is maintained by: Dr. Roger N. Clark rclark@speclab.cr.usgs.gov
Last modified Jan 23, 2003.