maptemplate

This program produces a PVL formatted file that contains the mapping group keywords required to transform an image to a map projection.

Required Input

• Map File Template output filename
• Projection name
• Additional parameters required for specific projections
• Input list if CALC option will be used

Output

A PVL formatted Map File Template containing mapping group keywords for the selected projection. The '.map' extension is appended to the output file automatically, if the file extension is not provided by the user. The output file may contain all or some of the map specifications listed below:

• User-preferred projection type (required)
• Other keywords required for specific projections
• Target body radii
• Latitude/longitude coverage or ground range
• Pixel resolution
• Latitude and longitude definitions
• Distance from center of target
• Standard parallels

Map File Template Creation

To convert a raw instrument/camera cube (Level1) to a map projected image (Level2) the user must (1) create a custom PVL formatted text file, (2) use this maptemplate application to produce one, or (3) use the automated, projection-specific Map File Template in $ISISROOT/templates/appdata/maps. Whichever method that you choose, the Map File Template should contain the necessary keywords to project an image.

Map File Template Creation Choices:

1. PVL formatted text file: you must make a list of parameters based on the projection you wish to use, and input the appropriate values for each. The following example is a custom Map File Template for defining the projection of an image of Mars to the sinusoidal projection:

    Group = Mapping
    TargetName         = Mars
    EquatorialRadius   = 3396190.0 <meters>
    PolarRadius        = 3376200.0 <meters>
    LatitudeType       = Planetocentric
    LongitudeDirection = PositiveEast
    LongitudeDomain    = 360
   
    ProjectionName     = Sinusoidal
    CenterLongitude    = 227.95679808356
   
    MinimumLatitude    = 10.766902750622
    MaximumLatitude    = 34.44419678224
    MinimumLongitude   = 219.7240455337
    MaximumLongitude   = 236.18955063342
   
    PixelResolution    = 426.87763879023 <meters/pixel>
    End_Group
   

The example above contains both required and optional keywords.


2. The maptemplate application: maptemplate will prompt you for all the necessary parameters to project your image. However, the planar and ring cylindrical projections are excluded from use in the application, because it requires keywords that are not defined in the program.
   
   
3. Templates in $ISISROOT/templates/appdata/maps: the template contains all the parameters necessary to project an image, and only the Projection name is "uncommented" in the file. This is because some projections only require that you enter a projection name, and the default values are computed for the remaining keywords. In such cases where the default value cannot be calculated using the camera model or ISIS system default, you must "uncomment" the appropriate line(s) of the template and set the values. See example below:

   Group = Mapping
     ProjectionName  = LambertConformal
   # CenterLatitude  = 0.0 <degrees>
   # CenterLongitude = 0.0 <degrees>
   # Earth (ographic)
   # FirstStandardParallel  = 33.0 <degrees>
   # SecondStandardParallel = 45.0 <degrees>
   
   # Mars (ographic)
   # FirstStandardParallel  = 35.83 <degrees>  *Remove # to uncomment and change 35.83 to your value
   # SecondStandardParallel = 59.17 <degrees>  *Remove # to uncomment and change 59.17 to your value
     End_Group
   

Identifying Required Parameters:

The following is a list of projections and keywords that are required. When a keyword is missing, and you try to project an image using projection software like cam2map, an error will occur. Below is a list of projections and the keywords that must be in the Map File Template:

PROJECTION	ASSIGN VALUES FOR THESE KEYWORDS
Lambert Conformal	FirstStandardParallel, SecondStandardParallel
Oblique cylindrical	PoleLatitude, PoleLongitude, PoleRotation
Point perspective	Distance
Planar (unavailable in maptemplate)	CenterRingRadius, CenterRingLongitude, RingLongitudeDirection, RingLongitudeDomain
Ring cylindrical (unavailable in maptemplate)	CenterRingRadius, CenterRingLongitude, RingLongitudeDirection, RingLongitudeDomain

How the defaults are set for Mapping Group keywords:

DEFAULT SOURCE	MAPPING GROUP KEYWORDS
From Label	TargetName
From camera model	CenterLatitude, CenterLongitude, MaximumLatitude, MaximumLongitude, MinimumLatitude, MinimumLongitude, PixelResolution, Scale
ISIS Map defaults	LatitudeType (ocentric), LongitudeDomain (360), LongitudeDirection (East), ScaleFactor (1)
From PCK file for Target	EquatorialRadius, PolarRadius
Not computed, user must set	CenterRingLongitude, CenterRingRadius, Distance, FirstStandardParallel, MaximumRingLongitude, MaximumRingRadius, MinimumRingLongitude, MinimumRingRadius, PoleLatitude, PoleLongitude, PoleRotation, RingLongitudeDirection, RingLongitudeDomain, SecondStandardParallel

Maptemplate GUI Interface

Radio buttons in the GUI are used to select options. Once an option is selected, the required parameters pertinent to that option become activated; therefore the user should complete the highlighted fields in the different parameter sections. Use the right scroll bar on the right side of the GUI to see all the available options.

The button is used for RNGOPT and RESOPT options. If the button is clicked, the range will be calculated and automatically entered in the GUI fields with the appropriate values. For SELECT, the button is used to select a Map File Template, the button is use to view the contents of the selected file at the bottom of the GUI, and the "Down Arrow" button is used to load the contents of the selected file into the appropriate GUI fields. When the target name is set and no other value is specified, the button next to EQRADIUS is used to display the system radii in the log area.

Parameter Setting Action

PARAMETER	ACTION
NONE	No keywords regarding the target will be added to the Map File Template. The value for the required keywords is derived based on the ISIS defaults at the time of projection. If a target name is specified and no value is entered for radius, the system radii will be used.
USER	The user must enter the target and the preferred settings for the selected projection. The user can select meters per pixel (MPP) or pixels per degree (PPD) to define the units for the value entered for Resolution. If MPP is chosen, the value is set for the keyword PixelResolution. If PPD is chosen, the value is set for the keyword Scale.
SELECT	The target definition information is retrieved from an existing Map File Template. The information can be displayed in the log area or loaded into appropriate GUI fields. The Help buttons located by the radial fields can only be used when the GUI is used to specify the parameters.
CALC	The application maptemplate will calculate the values using the files in the input list specified in the FROMLIST parameter. For the ground range, the keywords MinimumLatitude, MaximumLatitude, MinimumLongitude, and MaximumLongitude are set. The values for ground range are in degrees. For the resolution, the keywords PixelResolution and Scale are set. All the calculated values for resolution will be meters per pixel for the keyword PixelResolution.
RESCALCOPT	The PixelResolution value is set based on whether the user selected HIGH, LOW, or AVERAGE when the CALC option is used to calculate the resolution.

Other Uses for Your Created Map file: The output Map File can be used in applications that use projections, such as cam2map, map2map, mapsize, skymap, and more.

See "Learning About Map Projections" to learn more about mapping keywords.

This example shows the contents of a PVL text file generated by the maptemplate application. The settings are in default status for this example except for the output filename and center longitude which must be entered by the user.

Group = Mapping
  ProjectionName     = Sinusoidal
  CenterLongitude    = 0.0
End_Group
End
        

The text above is the contents of the map template file when the following command line is executed.

maptemplate map=out.txt clon=0.0

Maptemplate GUI

Example GUI Screenshot of maptemplate GUI before the center longitude was entered for the sinusoidal projection.

This example shows the contents of a PVL text file for a Lambert conformal map projection based on user selected options. The output file, projection type, center latitude, center longitude, first and second standard parallels, target option, and target name are entered. The remaining settings are left in their default state.

Group = Mapping
  ProjectionName     = LambertConformal
  CenterLongitude    = 0.0
  CenterLatitude     = 90.0
  StandardParallel1  = 45.0
  StandardParallel2  = 55.0
  TargetName         = Mars
  EquatorialRadius   = 3396190.0 <meters>
  PolarRadius        = 3376200.0 <meters>
  LatitudeType       = Planetocentric
  LongitudeDirection = PositiveEast
  LongitudeDomain    = 360
End_Group
        

The text shown above is the contents of the output file created when the following command line is executed.

maptemplate map=out.txt projection=LambertConformal clon=0.0 clat=90.0 par1=45.0 par2=55.0 targopt=user targetname=MARS