Level 2 Help for MARSJPLSTEREO

Left and right images of the stereo pair. There must two images for
input. Technically, the program does not care about the order of the
images, but the convention places the left image first.  Whichever is
first will be the reference image, i.e. the disparity map's geometry
will match the first image, with the map giving coordinates in the second.

A third input is possible for trinocular stereo but has not been tested.
Use at your own risk.

Output disparity map.  If one filename is given, a single 2-band image
will be created in REAL format, with the first band the Line disparity
and the second band the Sample disparity.  If two files are given, they
will both be single-band REAL images, where the first is Line disparity
and the second is Sample.

In all cases, the value of the pixel is the 1-based coordinate in the
second input image that matches the location of the pixel in the first
input image.  See MARSCORR for more file format details.

Corrected navigation filename.
If marsnav was run on the input images it created a table of corrected
pointing parameters. If you refer to this table using NAVTABLE it
will override the pointing parameters (e.g. azimuth and elevation) in the
picture labels, giving you a better registered mosaic.

This parameter is usually not very useful for stereo pairs, but is
included for completeness.

Pyramid level. Compute disparity at given Pyramid Level. Defaults
to 0.  The default will almost always be used in MIPL; low-resolution
results are rarely called for.

Comment from Mark Maimone:

0 is full resolution, 1 is half resolution in each dimension, 2 is
quarter, etc.  You typically get denser results at smaller resolution
(since camera calibration issues are less significant), but of course
the total number of range points typically drops. 

Size of the correlation window in pixels. Default : 7. 

Tuning this parameter is an art. Typically, larger values give smooth 
maps at coarse resolution and not very sensitive to small
objects. Small values give finer resultion of disparity maps, but may 
not converge on some pixels. 

Correlation is only attempted if both of the image dimensions are at 
least 3 times as big as window size.  If that's not the case, the program
just writes out dn=0.0 for all pixels.

Minimum allowed disparity value. Default : 0.

Disparities less then MINDISP will be rejected.

Maximum disparity value. Default : 63

Disparities larger then MAXDISP will be rejected.

Sets minimum Blob Size.  The blob filter removes correlations on noisy
pixels, such as the sky in the image, by removing regions of connected
pixels that are smaller than the blob size.  Disparity differences
between adjacent pixels must be less than 1/4 pixel to be considered
part of a blob region.

Comment from Mark Maimone. 
A sanity check is that we eliminate small, standalone blobs from the
range image.  Leaving the size at -1 means it will be set to some
fixed ratio of the image size (4%).  I.e., you will never see
connected regions in the disparity image smaller than 4% of the image,
unless you reset this value to some number of pixels.

Enables the Uncertainty filter, and sets its value.  Normally this filtering
is not done.  If UNCERTAINTY is specified, the filter is enabled, with a
value of the parameter value.

The Uncertainty filter rejects points based on the slope of the correlation
peak.  This is loosely related to correlation quality.

A value of 256 corresponds to a 1.0 pixel uncertainty in disparity value.
A value of 128 might be a place to start with this parameter, given some
comments in the correlator code.  Lower values create a more stringent
filter; i.e. fewer values survive, which should mean that the remaining
values are of higher quality.

Since the underlying correlator accepts only byte data, halfword data
must be scaled to byte internally before correlating.  This is done
via a percent stretch (linear stretch based on histogram analysis).

This parameter specifies the percent of pixels to be saturated at
either end of the DN range.  It is a percentage, so the value ranges
from 0 to 100 (not 0 to 1).  It defaults to 0.4%, which is very close
to 1/256.  The binning process during byte conversion will ideally put
1/256 of the pixels in each bin, so a value of 0.4% treats the end bins
similar to all of the other bins.

Normally all input images are lumped together into a single histogram
for the percent stretch calculation (see PERCENT).  Specifying SEPARATE
causes each image to be stretched independently, based on its own
histogram only.  This is useful for camera pairs whose overall brightness
levels aren't matched.  The correlator is rather sensitive to overall
brightness levels.

The vicar image band number for the input images.  Defaults to 1. If the 
specified band is bigger than the number of band in the image, the 1st band
will be processed. 

Set maximum Euclidean separation for trinocular stereo. DEFAULT = 0.2

Not used for binocular stereo. 

Set uncertainty threshold. DEFAULT = 1.0; Range = [0:255]

Set maximum Pixel Threshold for merge. 

Not used for binocular stereo. 

A colon-separated list of directories in which to look for configuration
and calibration files.  Environment variables are allowed in the list
(and may themselves contain colon-separated lists).  The directories are
searched in order for each config/cal file when it is loaded.  This allows
multiple projectes to be supported simultaneously, and allows the user to
override any given config/cal file.  Note that the directory structure below
the directories specified in this path must match what the project expects.
For example, Mars 98 expects flat fields to be in a subdirectory named
"flat_fields" while Mars Pathfinder expects them to be directly in the
directory specified by the path (i.e. no intermediate subdirectories).

Specifies a method for pointing corrections.

Loose method matchs with pointing parameters of the image.
Tight method matchs with unique id of the image.

Tolerance value for matching pointing parameters in the pointing corrections file.
Used if MATCH_METHOD=LOOSE
Default value is pretty arbitrary, though seems to work well so far....

Specifies a mission-specific pointing method to use.  Normally this
parameter is not used, in which case the "default" pointing methods
are used.  Some missions may have special, or alternate, pointing
methods available, which are indicated by this string (for example,
backlash models, using arm joint angles instead of x/y/z/az/el, etc).
A substring search is used, so multiple methods (where that makes sense)
can be specified by separating the keywords with commas.

Note that nav files created using one pointing method will most likely
not be compatible with a mosaic created using a different pointing method.

The methods available vary per mission, but some methods available at
the time of this writing are:

BACKLASH : Mars 98 SSI only.  Selects a backlash pointing model,
which adjusts the telemetered azimuth and elevation values based on
knowledge of the camera's mechanical backlash and the direction the
motor was travelling when the image was taken.

This parameter is not useful for MARSJPLSTEREO but is inherited with the
PIG library.  See e.g. MARSMAP for a description if necessary.

The DATA_SET_NAME typically identifies the instrument that acquired the
data, the target of that instrument, and the processing level of the data.
This value is copied to the output label, property IDENTIFICATION,
keyword DATA_SET_NAME.

The DATA_SET_ID value for a given data set or product is constructed
according to flight project naming conventions.  In most cases the
DATA_SET_ID is an abbreviation of the DATA_SET_NAME.
This value is copied to the output label, property IDENTIFICATION,
keyword DATA_SET_ID.

When a data set is released incrementally, such as every three months during
a mission, the RELEASE_ID is updated each time part of the data set is released.
For each mission(or host id if multiple spacecrafts), the first release of a data
set should have a value of "0001".
This value is copied to the output label, property IDENTIFICATION,
keyword RELEASE_ID.

Specifies a permanent, unique identifier assigned to a data product by
its producer. Most commonly, it is the filename minus the extension.
This value is copied to the output label, property IDENTIFICATION,
keyword PRODUCT_ID.

Specifies the unique identifier of an entity associated with the
production of a data set. This value is copied to the output label,
property IDENTIFICATION, keyword PRODUCER_ID.

Specifies the identity of a university, research center, NASA center or other
institution associated with the production of a data set.
This value is copied to the output label, property IDENTIFICATION, keyword
PRODUCER_INSTITUTION_NAME.

Specifies a target.  The target may be a planet, satelite, ring, region, feature,
asteroid or comet.  This value is copied to the output label, property
IDENTIFICATION, keyword TARGET_NAME.

Specifies the type of a named target. This value is copied to the output
label, property IDENTIFICATION, keyword TARGET_NAME.

Rover State File.  This is a list of filenames to load containing
Rover State information.  These files contain position and orientation
information for a rover (or other mobile spacecraft) at various sites.
They are in XML format.  See the "Rover Motion Counter (RMC) Master File SIS"
for details on these files.

Rover State Files have a priority order.  The files listed first have
the highest priority.

Environment variables may be used in the list.

For MER, if a directory is specified, then that directory is searched for
RMC Master files and any found are loaded.  The directory structure and
filename convention is covered in the RMC SIS.  The directory specified
is the one containing "master", so if <dir> is the name specified in the
RSF parameter, the following files will be searched for:

<dir>/master/_Master.svf
<dir>/master/_Site__Master.rvf

The name of each file loaded is printed to the stdout log for reference.

If enabled, this causes the internal database of RMC locations to be
printed out to the stdout log.  This is after the RSF files have been
loaded and the coordinate systems read from the input label(s).

This parameter is not useful for MARSJPLSTEREO but is inherited with the
PIG library.  See e.g. MARSMAP for a description if necessary.

This parameter is not useful for MARSJPLSTEREO but is inherited with the
PIG library.  See e.g. MARSMAP for a description if necessary.

This parameter is not useful for MARSJPLSTEREO but is inherited with the
PIG library.  See e.g. MARSMAP for a description if necessary.

Specifies which solution ID to use for pointng corrections.

There are potentially many different definitions for the same coordinate
system.  These are identified via a unique Solution ID.  If this parameter
is given, only the specified solution's definition is searched for.