map2map

This program will alter the projection of a cube which is already in a map projection (ISIS level2 cube). Pixels are physically moved using either a nearest neighbor, bilinear, or cubic convolution interpolator. Usage examples of this program include:

      1.  Converting from Sinusodial to Mercator or any other
          supported projection
      2.  No projection change but altering projection parameters
          such as center longitude or standard parallels
      3.  No projection change but altering pixel resolution
      4.  No projection change but altering latitude/ longitude window
      5.  No projection change but altering latitude types, 
          longitude domains, or longitude direction
      6.  Match the mapping parameters of another ISIS leve2 cube for
          comparison.   
    

If you need to generate your own map file you can use the maptemplate program or alternatively, hand create a file using your favorite editor. The map file need only specify the ProjectionName as defaults will be computed for the remaining map file parameters.

The map file can be an existing map projected (level2) cube. A level2 cube has PVL labels and contains the Mapping group. Depending on the values of the input parameters, the output cube can use some or all of the keyword values of the map file. For instance, setting MATCHMAP = true causes all of the mapping parameters to come from the map file, resulting in an output cube having the same number of lines and samples as the map file. If MATCHMAP = true and the map file is missing a keyword like PixelResolution, the application will fail with a PVL error. Setting MATCHMAP=false allows for some of the mapping components to be overridden by the user or computed from the FROM cube.

To learn more about using map projections in ISIS, refer to the ISIS Workshop "Learning About Map Projections".

Description

The specification of the input cube to be remapped. The cube must contain a valid Mapping group in the labels.

Type	cube
File Mode	input
Filter	*.cub

Description

A file containing the desired output mapping parameters in PVL. This file can be a simple label file, hand produced or created via the maptemplate program. It can also be an existing cube or cube label which contains a Mapping group. In the latter case the FROM cube will be transformed into the same map projection, resolution, etc.

Type	filename
File Mode	input
Default Path	$base/templates/maps
Default	$base/templates/maps/sinusoidal.map
Filter	*.map *.cub

Description

This file will contain the results of the remapping.

Type	cube
File Mode	output
Filter	*.cub

Description

This forces all of the mapping parameters to come from the map file. Additionally, when the map file is an image the TO file will have the same number of lines and samples as the map file.

Type	boolean
Default	FALSE
Exclusions	PIXRES RESOLUTION DEFAULTRANGE MINLAT MAXLAT MINLON MAXLON

Description

This parameter is used to specify how the pixel resolution is obtained for the output map projected cube.

Type	string
Default	FROM
Option List:	Option Brief Description FROM Read resolution from input cube This option will automatically determine the resolution from the input cube. Exclusions RESOLUTION MAP Read resolution from input map file This option will use either the PixelResolution (meters/pixel) or Scale (pixels/degree) in the map file. Exclusions RESOLUTION MPP Get resolution from user in meters per pixel This option allows the user to specify the resolution in meters per pixel using the RESOLUTION parameter Inclusions RESOLUTION PPD Get resolution from user in pixels per degree This option allows the user to specify the resolution in pixels per degree using the RESOLUTION parameter Inclusions RESOLUTION

Description

Specifies the resolution in either meters per pixel or pixels per degree

Type	double
Minimum	0.0 (exclusive)

Description

This parameter is used to specify how the default latitude/longitude ground range for the output map projected image is obtained. The ground range can be obtained from the input cube or map file. Note the user can overide the default using the MINLAT, MAXLAT, MINLON, MAXLON parameters. The purpose of the ground range is to define the coverage of the map projected image. Essentially, the ground range and pixel resolution are used to compute the size (samples and line) of the output image.

Type	string
Default	FROM
Option List:	Option Brief Description FROM Read default range from input cube This option will automatically determine the mininum/maximum latitude/longitude from the input cube specified using the FROM parameter. MAP Read default range from map file This option will read the mininum/maximum latitude/longitude from the input map file.

Description

The minimum latitude of the output map. If this is entered by the user it will override the default input cube or map value.

Type	double
Internal Default	Use default range
Minimum	-90.0 (inclusive)
Maximum	90.0 (inclusive)

Description

The maximum latitude of the ground range. If this is entered by the user it will override the default input cube or map value.

Type	double
Internal Default	Use default range
Minimum	-90.0 (inclusive)
Maximum	90.0 (inclusive)
Greater Than	MINLAT

Description

The minimum longitude of the ground range. If this is entered by the user it will override the default input cube or map value.

Type	double
Internal Default	Use default range

Description

The maximum longitude of the ground range. If this is entered by the user it will override the default input cube or map value.

Type	double
Internal Default	Use default range
Greater Than	MINLON

Description

If this option is selected, pixels outside the latitude/longtiude range will be trimmed or set to null. This is useful for certain projections whose lines of latitude and longitude are not parallel to image lines and sample columns.

Type	boolean
Default	FALSE

Description

This is the type of interpolation to be performed on the input.

Type	string
Default	CUBICCONVOLUTION
Option List:	Option Brief Description NEARESTNEIGHBOR Nearest Neighbor Each output pixel will be set to the pixel nearest the calculated input pixel. BILINEAR Bi-Linear interpolation Each output pixel will be set to the value calculated by a bi-linear interpolation of the calculated input pixel. CUBICCONVOLUTION Cubic Convolution interpolation Each output pixel will be set to the value calculated by a cubic convolution interpolation of the calculated input pixel.

This example shows how to use map2map to match a system LOLA DEM to a Clementine 750 base tile available from PDS.

map2map map2map from=/usgs/cpkgs/Isis3/data/base/dems/LRO_LOLA_LDEM_global_128ppd_20100915_0002.cub map=clembase_30s135_256ppd.cub matchmap=yes to=LOLA_clembase_30s135_256ppd.cub

map2map MATCHMAP example GUI top	Top of GUI for map2map MATCHMAP example The from file is a system LOLA dem. The MAP is an Isis level 2 image. The output file will be a section of the dem extracted out and remapped into the same state as the level 2 image entered as MAP. Because MATCHMAP is checked, all mapping parameters will be determined from MAP, and any listed in the GUI are grayed out.
map2map MATCHMAP example GUI top	Middle of GUI for map2map MATCHMAP example This is the middle of the GUI for the map2map MATCHMAP example. It shows everything grayed out in the output map ground range box because MATCHMAP was checked in the previous image. The default INTERP is selected.
map2map MATCHMAP example GUI top	Bottom of GUI for map2map MATCHMAP example This is the bottom of the GUI for the map2map MATCHMAP example. It shows the state of the GUI when the application has completed.

Input image (dem) to be reprojected	FROM for map2map MATCHMAP example Parameter Name: FROM This is a LOLA global dem stored in the Isis system. A section of this file matching the coverage of MAP will be extracted and reprojected to match MAP.
Isis level 2 MAP	MAP for map2map MATCHMAP example Parameter Name: MAP This is a base tile from the PDS Clementine 750.

MATCHMAP example TO

TO for map2map MATCHMAP example Parameter Name: TO This is a section of the LOLA global dem extracted and remapped to match a base tile of the PDS Clementine 750. Notice how the geometry matches the geometry of the second input image above (MAP).

In this example the polar portion of a Messenger/Mariner10 global mosaic is extracted and transformed to a PolarStereographic projection. The pixel resolution is reduced from 500 m/pix to 1000 m/pix. Also the trim option is exercised to null the pixels outside of the lat/lon boundary and generate a circular output image instead of a square.

map2map map2map from=MessengerFlyby_Mariner10_blobal.cub map=npola.map to=MessengerFlyby_Mariner10_north_polar.cub pixres=map defaultrange=map trim=yes

map2map MATCHMAP example GUI top

Top of GUI for map2map TRIM example The FROM file is a Messenger/Mariner10 global Equirectangular mosaic. The MAP file defines a PolarStereographic projection. The TO file will be the polar section of the FROM extracted out and transformed into a PolarStereographic projection. Notice that PIXRES specifies that the resolution is to be read from the MAP. If the pixel resolution is missing from the map file, the application will throw an error.

map2map MATCHMAP example GUI top

Bottom of GUI for map2map TRIM example This is the bottom of the GUI for the map2map TRIM example. It shows that the default map ground range will be read from the MAP. If the ranges are not in MAP, the application will throw an error. Also notice that the TRIM option has been selected.

Input image (dem) to be reprojected

FROM for map2map TRIM example Parameter Name: FROM This is a Messenger/Mariner10 global mosaice in an Equirectangular map projection. The north polar section of this file will be extracted and transformed to a Polar Stereographic projection and trimmed to the exact lat/lon range specified in the map file, forming a circle.

View PVL mapping file	The is the mapping file that defines the output map projection. Since the default range is set to MAP as well, it also contains the desired lat/lon range of the output level 2 image.

Output PolarStereographic projection of north pole

TO for map2map TRIM example Parameter Name: TO This is the north polar section of the Messenger/Mariner10 global mosaic of Mercury in an Polar Stereographic projection and trimmed to the exact lat/lon range specified in the map file to form a circle.