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The maplab application is used to geo-reference a map-projected cube by
adding or updating the Mapping Group with projection and geo-referencing
information. Maplab takes as input a map-projected cube and a map file.
The user has the option to geo-reference by (LATITUDE,LONGITUDE)-coordinates
or by (X,Y)-map-projected-coordinates that correspond to a given
(SAMPLE,LINE)-coordinate in the input cube.
The map file must contain information pertaining to the specifics of the
cube's map-projection parameters, along with the target, body radius,
longitude direction, latitude type and scale. We suggest running the
maptemplate program to generate the map file provided as input.
NOTE that when selecting a SAMPLE and LINE for referencing known coordinates
to a pixel, pixel coordinate (0.5, 0.5) is the top-left corner of the top-left
pixel in the cube. By extension, (1.0, 1.0) is the center of the top-left
pixel, and (1.5, 1.5) is the lower-right corner of the top-left pixel.
The input map will now use pixels/degree if no pixel resolution is found.
If neither are present, throws an error. Both PixelResolution and Scale
(pixels/degree) keywords will be in the output.
Travis Addair
2009-11-06
Added error checking to ensure that the provided map file has all the
necessary keywords for later processing, and enhanced documentation to
discuss necessary keywords and pixel coordinates.
Mackenzie Boyd
2011-04-11
Changed parameter LONG to LON, removed duplicate code.
Tracie Sucharski
2012-12-06
Changed to use TProjection instead of Projection. References #775
Parameters
Input Files
The cube whose label will be updated with Mapping Group information.
Type
cube
File Mode
input
Filter
*.cub
File containing map projection parameters.
Type
filename
File Mode
input
Filter
*.map
Input Values
The SAMPLE coordinate in the cube that corresponds to a known
(X,Y) or (LATITUDE,LONGITUDE) coordinate. In ISIS, the upper-left
corner of the upper-left pixel has coordinate 0.5.
Type
double
The LINE coordinate in the cube that corresponds to a known
(X,Y) or (LATITUDE,LONGITUDE) coordinate. In ISIS, the upper-left
corner of the upper-left pixel has coordinate 0.5.
Type
double
A list of the different types of coordinates allowed by the
application.
Type
string
Default
XY
Option List:
Option
Brief
Description
XY
Allows X, Y as Input Values
This option allows the user to enter the (X,Y) map projected
coordinate (in meters) that corresponds to the given
(SAMPLE,LINE) coordinate.
This option excludes LATITUDE and LONGITUDE input values.
Exclusions
LAT
LON
Inclusions
X
Y
LATLON
Allows LAT, LON as Input Values
This option allows the user to enter the (LATITUDE,LONGITUDE)
coordinate that corresponds to the given (SAMPLE,LINE) coordinate.
The (LATITUDE,LONGITUDE) coordinate is in decimal degrees, and must
be in the same LatitudeType and LongitudeDomain listed in the map file.
This option excludes X and Y input values.
Exclusions
X
Y
Inclusions
LAT
LON
The map-projection X-coordinate, in meters, corresponding to the
the given (SAMPLE,LINE) coordinate of the cube.
Type
double
The map-projection Y-coordinate, in meters, corresponding to the
given (SAMPLE,LINE) coordinate of the cube.
Type
double
Latitude coordinate, in decimal degrees, for the given
(SAMPLE,LINE) coordinate of the cube. It must be in the same
LatitudeType listed in the map file.
Type
double
Longitude coordinate, in decimal degrees, for the given
(SAMPLE,LINE) coordinate of the cube. It must be in the same
LongitudeDomain listed in the map file.
Type
double
Example 1
GeoTiff Header
Most outside applications use the top left pixel (either upper-left edge
or center) to define their location in X, Y. For example, a GeoTiff with
an internal header, uses the upper left edge and for an example may
report: Upper Left (2883258.0, 979924.0) -- meaning (X, Y). Thus for
maplab, one would need to use the same top left corner of the pixel for
ISIS, as illustrated in the command line below.
Command Line
Mapping the upper-left of an ISIS cube (0.5, 0.5) to the upper left of
the example image (2883258.0, 979924.0).
A typical image that has a "GIS Worldfile", in contrast to an internal
GeoTiff header, uses the center of the top left pixel to define its
location in X, Y. Thus a Worldfile might look like myImage.wld or *.tfw,
*.jgw, *.pgw (depending on image type):
2.0 Cellsize in X (meters)
0.0 rotation/skew (normally 0)
0.0 rotation/skew (normally 0)
-2.0 Cellsize in Y (meters)
-24243.731055 Upper-left pixel center X (meters)
815863.281183 Upper-left pixel center Y (meters)
Thus for this example the user would need to run the program with the
command line that follows.
Command Line
Mapping the center of the upper-left pixel of an ISIS cube (1.0, 1.0)
to the center of the upper left of the example image (2883258.0,
979924.0).
Generally one will try to bring in a polar file which is 0 to 360 lon,
extends to a common lat range, and centered at the pole (clat = 90 or
-90). Nothing about the extent in meters is needed if the center of the
image is again 90 or -90 lat. Again GIS/RS application will still
to the upper left pixel but manually this can be harder to use
than just using the center which will be defined as X,Y = 0,0 when in a
Polar or Lambert Azimuthal projection. Using an example where the polar
image is 2000 lines by 2000 samples then the run would look like:
