Level 2 Help for FIXVGR

STRING--REQUIRED
Specifies the input image.  The image must have been radiometrically
corrected by "ficor77" and be in 16-bit integer (halfword) data format.
It may be any size (e.g. 800x800 geometrically uncorrected,
1000x1000 geometrically corrected, map projected) as long as it is in
the same radiometric scale as the "ficor77" output.

STRING--REQUIRED
Specifies the output image.

4 INTEGERS--OPTIONAL
	SIZE=(sl,ss,nl,ns)
Specifies the input image area to be processed by starting line, starting
sample, number of lines, and number of samples.  The output image will
be nl x ns samples in area.
If defaulted, the entire image is processed.

INTEGER--OPTIONAL
The Starting Line in the input picture to be used for the output 
picture.  The default is SL=1.

INTEGER--OPTIONAL
The Starting Sample in the input picture to be used for the output
picture.  The default is SS=1.

INTEGER--OPTIONAL
The Number of Lines in the input picture to be processed to the
output picture.  If defaulted, all image lines are processed.

INTEGER--OPTIONAL
The Number of Samples in the input picture to be processed to the
output picture.  If defaulted, NS is the entire width of the input image.

KEYWORD--OPTIONAL
Specifies the planet-of-encounter.  Valid values are Jupiter, Saturn, Uranus,
or Neptune.

For Voyager 1, the planet-of-encounter is always set to Jupiter, and this
keyword is ignored (only Jupiter scale factors are available for VGR-1).

If defaulted for Voyager 2, the planet-of-encounter is determined by
searching the frame label for a valid PICNO, Spacecraft-Event-Time (SCET)
or Earth-Received-Time (ERT), in that order.  If the fifth character of the
PICNO is a 'J','S','U', or 'N', this is accepted as a valid planet ID.
Otherwise, if the SCET or ERT year is greater than 74, the planet is determined
as follows:

	ERT YEAR	PLANET	   VGR-1 Encounter   VGR-2 Encounter
	--------	------	   ---------------   ---------------
	less than 80	Jupiter	     Mar  5 79		Jul  9 79
	80 to 84	Saturn	     Nov 12 80		Aug 25 81
	85 to 87	Uranus				Jan 24 86
	88 and beyond	Neptune				Aug 24 89

INTEGER--OPTIONAL
  Ex: CAMERA=4
Specifies the camera ID (serial number) of the input image (PIC).  This
overrides the camera ID extracted from the image's picture label.  The
camera serial numbers of the Voyager spacecraft are:
	4 = VGR-2 WA		6 = VGR-1 WA
	5 = VGR-2 NA		7 = VGR-1 NA

INTEGER--OPTIONAL
	Ex: FILTER=4
Specifies the camera filter position for the input image.  The filters are
mounted on an 8-position filter wheel as follows:

	#  Narrow-Angle   Wide-Angle
	-  ------------   ----------
	0  Clear	  Methane (J-S-T)
	1  Violet	  Blue	  
	2  Blue		  Clear
	3  Orange	  Violet
	4  Clear	  Na-D
	5  Green	  Green
	6  Green	  Methane (U)
	7  Ultraviolet	  Orange

This parameter overrides the filter position extracted from the label of
the input image.

KEYWORD--OPTIONAL
Valid: 'NONEG
Specifies that all negative DNs will be set to zero.  The default is to output
rescaled negative numbers.  NONEG is a relic of the IBM days when "geoma" 
would die by ingesting negative DN values.

KEYWORD--OPTIONAL
Valid: 'NOCORREC
Specifies that no scale correction is to be done.  If both 'NOCORRECT and
'NONEG are specified, the output image is the same as the input image except
that all negative DNs have been set to zero.  If 'NOCORRECT is specified but
'NONEG is not specified, the output image is an exact copy of the input
image.  In practice, the NONEG and NOCORRECT keywords are no longer used.

STRING--OPTIONAL
	Ex:  SCF="/project/test_work/testdata/mipl/vgr/vgrscf.dat"
Specifies the Scale Correction File, as generated by program "ficorgen".
Note that since this file is rarely updated, the default usually points to
the most recent file and this parameter is normally not specified.

Note: The default location for the SCF points to a location at the MIPS
facility.  When running FIXVGR at another facility, please copy the SCF and
point to the new location.