Author:		Jeannie Walldren
Date:		2008-06-11
History:
	2008-06-11 Jeannie Walldren 
			- Original version
	2009-05-21 Jeannie Walldren 
			- Changed step 1 vicar2isis "from" parameter to take in *.img file, not *.lbl file.
			- Changed step 2 idl "read_tif" command to "read_tiff".
			- A comparison of the version 2 files to version 1 files shows no change.


This directory contains calibration files for ISIS 3 CISSCAL's flatfield dustring and mottle corrections.
They are derived from Cassini Orbiter ISS Volume 11 Version 2 (i.e. coiss_0011_v2).

	AAREADME_dustring_isis3.txt 
		- This document, written for ISIS 3 CISSCAL info.
	dustring_info.txt  
		- Describes original contents used by IDL CISSCAL 3.6


In the idl CISSCAL application file cassimg_dustring.pro, dustring file 
*.img and mottle file *.tif were used, so we create cubes from these.  
If newer versions become available the following steps can be used to convert 
them into cubes.

	nac_dustring_venus.full.cub
	nac_dustring_venus.sum2.cub
	nac_dustring_venus.sum4.cub
	nac_mottle_1444733393.full.cub

1) The dustring cubes were created using VICAR2ISIS and REDUCE

      	> vicar2isis from=nac_dustring_venus.img to=nac_dustring_venus.full.cub
	> reduce from=nac_dustring_venus.full.cub to=nac_dustring_venus.sum2.cub ons=512 onl=512
	> reduce from=nac_dustring_venus.full.cub to=nac_dustring_venus.sum4.cub ons=256 onl=256


2) The .raw file was derived from file nac_mottle_1444733393.tif by 
  the following commands in idl:

	img = read_tiff('nac_mottle_1444733393.tif',image_index=i)
	openw, lun_out, "nac_mottle_1444733393.raw", /get_lun
	writeu,lun_out,img
	close,lun_out
	free_lun,lun_out

3) The *.raw file was imported using raw2isis.  According to the idl code, for now, 
  we assume no mottle correction needed for summed images.

	> raw2isis from=nac_mottle_1444733393.raw to=nac_mottle_1444733393.full.cub samples=1024 lines=1024 bittype=real