Level 2 Help for MARSCHKOVL

INP

There are two options for describing input images. 

Either a single  ascii file or 2 ascii files with the file names listed, 
one per record.


OUT

2 output files. The first is a list of the left image filnames  of each image
pair satisfying the overlap test. The second is a list of the right image
filenames.
 


OVERLAP

Minimum acceptable percentage overlap.
Left/right pairs with an overlap percentage  below OVERLAP  will be rejected. 


NAVTABLE

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.



BAND

The vicar image band number. Defaults to 1


BORDER

The width of a border all around the image.
Defaults to 9.
 





SPACING

The stride to the next sample in the reference image.
Also, the stride to the next line in the reference image.
Setting this to a value other than 1 causes a subsampling of the reference
image.


SEP_ANGLE

Maximum separation angle for image pairs.  If the camera orientations are
separated by more than this angle, the pair is skipped.  This provides a
quick efficiency boost by rejecting spurious pairs.

Typical values:  sep_angle=53 for MER navcam
                 sep_angle=36 for MER pancam

TBD: This should be calculated from the camera FOV in the future.




NORMAL

The local mars surface normal vector coordinate system specified by SURF_COORD 
parameter (defaults to surface fixed).
For most pan/tilt cameras, if the lander is not tilted this vector
would be: normal=(0,0,-1).  ie: x_component=0, y_component=0, z_component=-1.
This need not be a unit vector.  This vector is used to define the
surface plane to which image points are projected in order to minimize
parallax.
For SPHERE1/2 surface models, normal's first parameter is used to
denote sphere's radius.  Thus to describe sphere of radius R, user
would specify normal=(R, 0, 0).


GROUND

Any point on the surface, in coordinate system specified by SURF_COORD parameter
(defaults to surface fixed).  This defines where the tilted plane is in space.  
Although any point may be used, normally the point just "under" the origin is selected.
Defaults:
Mars Pathfinder:  (0.0, 0.0, 0.0)       (lander zero point is on the ground)
Mars 98 Lander:   (0.0, 0.0, 1.64)      (lander zero point is on top of deck)
MER           :   (0.0, 0.0, 0.294)
For MER images taken on top of the lander, the ground is roughly at (0.0, 0.0, 0.7)
For SPHERE1/2 surface models, GROUND parameter is used to denote sphere's
center.  
    


SURF_COORD

The coordinate system that surface parameters like GROUND and NORMAL are defined in.
For valid values refer to COORD parameter description.  The interpretation of the 
values is dependent on the mission. Defaults to surface fixed coordinate system.
Note that no validation is done for input strings because COORD is using the same
values.  So user needs to be extra careful in specifying SURF_COORD value.  For 
example COORD=local would be correctly interpreted to mean LOCAL_LEVEL because of
validation process.  On the other hand specifying SURF_COORD=local would lead
to underlying code treating the input value as invalid and reverting to default
which is FIXED frame.  So the values for SURF_COORD should be spelled exactly as
found in the list of valid values for COORD parameter.



SURFACE

The type of mars surface to use. The surface is used to intercept view rays
emanating from the cameras in order to model out parallax between the
stereo cameras. The options are surface=INFINITY which means no surface
is used, surface=PLANE (the default case). If surface = PLANE then the plane
is defined by the NORMAL and GROUND parameters.  For the cases when PLANE 
doesn't match local topography sufficiently well, here are two sphere surface
models: surface=SPHERE1 and surface=SPHERE2.  SPHERE1 is useful to model
convex surfaces like hills, it returns closest(first) ray-surface intersection 
point.  SPHERE2 is useful to model concave surfaces, like crater when the
camera point is outside looking in, it returns farthest(second) ray-surface 
intersection point.  For the case when camera is inside the sphere surface, 
like rover sitting in the crater, there is only a single intersection point
and SPHERE1 and SPHERE2 behave exactly the same. Last, MESH is a surface
model defined by a mesh file (.obj) which path is given with SURF_MESH.


SURF_MESH

Mesh OBJ file to use as the surface model. For the mesh to be used,
SURFACE must be set to MESH. The coordinates of the mesh vertices can be 
expressed in any CS. However the mesh CS must be supplied via SURF_CSFILE.
If SURF_CSFILE is not used, then the mesh is assumed to be to the CS that
results from COORD or SURF_COORD

VARI SURF_CSFILE 
File name of a vicar file whose CS (contained in the labels) will be read and
assigned to the SURFACE model. The type of image and its content are of no
interest, we are just reading the CS. That CS will supersede any other surface 
CS definition (COORD or SURF_COORD). Its typical use is to supply a CS to a
given mesh file (expectedly the XYZ from which the mesh is computed from, but
doesn't have to). But SURF_CSFILE could be use to define a CS in which NORMAL 
and GROUND for a PLANE surface are expressed in.



CONFIG_PATH

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).


POINT_METHOD

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.


NOSITE

Disables all label-derived parameters to the Site mechanism which underlies
coordinate systems.  This forces all sites to be identical, with all rotations
and offsets set the same.  In the case of MPF or Mars 98, this disables
the lander quaternion and offset (sets them to identity and 0, respectively).
This option should not be used with images taken from different vantage
points (e.g. the spacecraft moved, or mixing a lander and a rover) or
invalid results will be obtained.  The use of this option invalidates the
Fixed coordinate frame; any values reported in the Fixed frame will not
correctly reflect the orientation of the lander/rover.

Obviously, this option should be rarely used; it is intended for when the
image labels defining the site are invalid or inconsistent.


RSF

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.


DEBUG_RSF

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).


COORD

This parameter is ignored by marschkovl.  It is here for compatibility
with subroutines used by other programs (see e.g. marsmap).


COORD_INDEX

This parameter is ignored by marschkovl.  It is here for compatibility
with subroutines used by other programs (see e.g. marsmap).


FIXED_SITE

Specifies which major Site is the "Fixed" Site for this run.

Historically, MPF and M98 had a single "Surface Fixed" frame which never
moved, and which all other coordinate system frames were referenced to.
With the advent of long-range rovers (such as MER and FIDO), that became
insufficient.  The rover traverses far enough that errors in knowledge of
coordinate system offset and orientation become unacceptable.

For this reason, a system of major Sites was introduced.  Periodically
during the mission, a Site frame is declared.  This then becomes the
reference frame for all activities until the next Site is declared.
References are kept local, and errors don't propogate across Sites.

However, if images from more than one Site are combined together, the
Site's must be placed relative to each other.  Therefore a single reference
frame is still needed to combine different sites.

The FIXED_SITE parameter controls which of the major Site frames is
the reference ("fixed") site for this program run.  This fixed frame
can vary in different program runs, but is constant throughout one
execution.

If not specified, FIXED_SITE defaults to the minimum Site number (i.e.
lowest numbered, or earliest chronologically) used in all input images.
Normally this default is sufficient; rarely must FIXED_SITE be specified.

One or more Rover State Files must usually be specified in order to combine
image from more than one Site.  These describe the relationship between
sites.  See the RSF parameter.