C code routines for the BYU-MERS "SIR" image file format


The BYU-MERS "sir" image format was developed by the Brigham Young
University (BYU) Microwave Earth Remote Sensing (MERS) research group
to store images of the earth along with the information required to
earth-locate the image pixels.

Note that these routines use the C-standard pixel address from 0 to N-1
rather than the SIR-standard pixel address from 1 to N.  Note, however, that
(1,1) is in the lower left of the image of a SIR File.  For an input location
of pixel (1,1) the Lat,Lon values returned by pixtolatlon correspond to 
the location of the lower-left corner of the (1,1)th pixel.

This directory contains several programs which illustrate reading and
writing BYU SIR files.  The programs include utilities to convert the
SIR files into other file formats.

Library routines are in lib/ and include sir_io.c which has the read/
write routines, sir_geom.c which contains the geometry routines, and
sir_ez.c which is an easy interface to the low-level routines in
the other two files. The files dsir_geom.c and dsir_ez.c are double
precision version of sir_geom.c and sir_z.c. The library interfaces
are documented in the include files include/sir3.h (for sir_io.c and
sir_geom.c) and include/sir_ez.h for the sir_ez.c routines.

The tools/ directory contains example programs and utilities.  These
illustrate how to call the various routines and to convert SIR files to
various other image types.

Code is SIR header version 3.0 compliant.

Last revised:  12 Oct 2022  DGL
(c) 1999, 2000, 2002, 2014, 2019, 2022 BYU MERS