maplab Documentation

maplab - Put map projection information on cube labels
MAPLAB adds mapping keywords to the cube labels.  This program should
only be used on cubes that do not have existing mapping keywords on the
labels, or the longitude range needs to be offset 360 degrees to conform
to other cubes.

The table in the PROJ parameter description lists which parameters are
needed for each projection.

A common use of maplab is to allow the user to work from the -180 to 180
degree longitude system to the 0 to 360 degree system.  For example,
making a SIMP mosaic of the farside of the Moon from a global mosaic
with the -180 to 180 degree system is not possible.  However by
converting the mosaic to the 0 to 360 degree system the farside only map
can be made.

Initialize the 0 to 360 map with the 0-180 range from the -180 to 180
The output map will have the 0 to 180 (left side) range filled, the
180 to 360 will be empty (right side).

     mosaic from=moon.cub to=temp360	init=y lon=(0,360) lat=(-65,65)

Make a copy of the original -180 to 180 mosaic so you can alter the
the labels on the original data.

     dsk2dsk from=moon.cub to=temp.cub

Add 360 degrees to the longitudes using maplab.  This will put the
-180 to 0 portion of the original map into the range 180 to 360,
this is the range you need to finish the mosaic.

     maplab from=temp offset=360

You will also need to adjust the center longitude as it was shifted
in the previous call to maplab.

     maplab from=temp clon=0

Now simply mosaic the coordinated shifted mosaic onto the 0 to 360
mosaic, this will fill in the missing 180 to 360 portion (right side).

     mosaic from=temp to=temp360

Now simply pull out the farside range, 90 to 270 degrees.

     mosaic from=temp360 to=farside init=y lon=(90,270) lat=(-65,65)

done

PROGRAMMER: Kay Edwards, USGS, Flagstaff, AZ

Input cube file name
(default extension is .cub)

NONE

Planet name

--

Projection

--

Latitude range

--

Longitude range

--

Image resolution (km/pix)
   or

--

Image resolution(pix/deg)

--

Center longitude of projection

--

Center latitude of projection

--

First standard parallel

--

Second standard parallel

--

Scale factor

1.

Time of planet rotation (min)

--

Time of satellite revolution
(min)

--

Orbit inclination

--

Longitude of ascending node

--

Height above planet (km)

--

Latitude of control point 1

--

Longitude of control point 1

--

Latitude of control point 2

--

Longitude of control point 2

--

Maximum libration (deg)

11.0

Map rotation

--

Latitude of new pole

--

Longitude of new pole

--

Optional control points:
lat,lon,line,samp of point1

--

lat,lon,line,samp of point2

--

Longitude offset (-360.,0.,360.)

0.

Remove map labels (YES,NO)

NO

ADDITIONAL NOTES:

Parm	Description
FROM	Input cube file name. If the file extension is omitted, then ".cub" will be assumed.
PLANET	Use this parameter to enter the planet name if it does not exist on the labels.
PROJ	A four letter abbreviation is used for the projection name. The following table lists all possible projections, the abbreviation, and the parameters needed for each projection. KEYWORD PROJECTION PARAMETERS REQUIRED ALBE Albers Conical Equal-area CLON,CLAT,PAR1,PAR2 ALEX** Modified LAMA MLIB AZEQ Azimuthal Equidistant CLON,CLAT CYLI Cylindrical Equal-area CLAT* ECON Equidistant Conic CLON,CLAT,PAR1,PAR2 GNOM Gnomonic CLON,CLAT LAMA Lambert Azimuthal Equal-area CLON,CLAT (+90 to -90 from CLON,CLAT) LAMB Lambert Conformal CLON,CLAT,PAR1,PAR2 LAMG Lambert Azimuthal Equal-area CLON,CLAT (+170 to -170 from CLON,CLAT) MERC Mercator CLON,CLAT* MILL Miller Cylindrical CLON MSC Modified Stereographic Conformal OMER Oblique Mercator or Hotine CLON,CLAT,SCFA,INCL LAT1,LON1,LAT2,LON2 ORTH Orthographic CLON,CLAT POIN Point Perspective CLON,CLAT,DIST POLA Polar Stereographic CLON,CLAT* POLY Polyconic CLON,CLAT ROBI Robinson CLON SIMP Simple Cylindrical CLON,CLAT* or Equirectangular SINU Sinusoidal CLON SOM Space Oblique Mercator TIM1,TIM2,INCL,ASCN STER Stereographic CLON,CLAT TRAN Transverse Mercator CLON,CLAT,SCFA UTM Universal Transverse Mercator CLON,CLAT,SCFA VANG Van der Grinten I CLON *CLAT defines the latitude of true scale for the following projections: CYLI, MERC, POLA and SIMP. **See Hugh Kieffer for questions about this projection. Most of these projections are described by John Snyder in U.S.G.S. Professional Paper 1395, titled "Map Projections - A Working Manual".
LAT	The latitude boundaries of the projection. If the precise values are not known, use approximate values and use two control points. (see POINT1)
LON	The longitude boundaries of the projection. If the precise values are not known, use approximate values and use two control points. (see POINT1)
KM	Resolution is usually specified in kilometers/pixel, degrees/pixel or pixels/degree. KM is the resolution of the cube in km/pix. Either this parameter or DEG can be used to enter the desired resolution. The equations relating the two parameters are: KM=RADIUS*.0174533/DEG or DEG=RADIUS*.0174533/KM If both DEG and KM are specified, an error message will be issued and the program will bomb.
DEG	DEG is the resolution of the cube in pix/deg. Either this parameter or KM may be used to enter resolution. If the desired resolution is given in degrees/pixel such as: 1/32 deg/pix, or .03125 deg/pix then the inverse must be used, which is DEG=32 (pix/deg).
CLAT	Projections requiring a center latitude are ALBE, AZEQ, CYLI, ECON, GNOM, LAMA, LAMB, LAMG, MERC, OMER, ORTH, POIN, POLA, POLY, SIMP, STER, TRAN and UTM. The center latitude defines the latitude of origin of the projection, except for the following projections: CYLI, MERC, POLA and SIMP, where it defines the latitude of true scale. It is a parameter defined by the user of the final product. If working with cubes that will be computer mosaicked, then the center latitude for all those cubes must be the same. The valid range is from -90. degrees to 90. degrees.
CLON	Projections requiring a center longitude are ALBE, AZEQ, ECON, GNOM, LAMA, LAMB, LAMG, MERC, MILL, OMER, ORTH, POIN, POLA, POLY, ROBI, SIMP, SINU, STER, TRAN, UTM and VANG. The center longitude defines the central meridian of the projection, not necessarily the center of your input or output cube. It is a parameter defined by the user of the final product. If working with cubes that will be mosaicked, then the center longitude for all those cubes must be the same. If the TRAN is being used on Earth, there is a convention used of defining the center longitude of 6 degree wide zones (Universal Transverse Mercator or UTM). These zones are defined by measuring 6 degree increments from 0 degrees longitude. This means that the center longitudes of these zones start at 3 and go in increments of 6 degrees through 357 degrees. Or from -177 degrees to 177 degrees. On Earth, Venus and the Uranian system longitude is positive to the east. The rest of the solar system is positive to the west. The valid range is from -360 degrees to 360 degrees.
PAR1	Projections requiring standard parallels are ALBE, ECON and LAMB. Standard parallels must have the same sign as the latitude range of the projection. If no standard parallels are entered by the user for Lambert Conformal, the following values will be used. PLANET PAR1 PAR2 ------- ---- ---- CALLISTO 30. 58. EARTH 33. 45. GANYMEDE 30. 58. MARS 35.83 59.17 MERCURY 30. 60. If no standard parallels are entered by the user for Albers Equal-area, the following values will be used. PLANET PAR1 PAR2 ------- ---- ---- EARTH 29.5 45.5
PAR2	See PAR1
SCFA	The projections requiring a scale factor are OMER, TRAN and UTM. This is the ratio between true scale at some standard point such as a standard parallel and the scale at any given point. This value is normally left at 1. The UTM sets SCFA=.99996. The UTM should only be used for Earth.
TIM1	The SOM is the only projection requiring the time of planet rotation. TIM1 is the length of Earth's rotation with respect to the precessed ascending node of the satellite orbit in minutes. For Landsat this value is 1440 minutes or one day (See Snyder).
TIM2	The SOM is the only projection requiring the time of satellite rotation. TIM2 is the time required for one revolution of the spacecraft in minutes. For Landsat 1,2,3 TIM2=103.267, for Landsat 4,5 TIM2=98.884.
INCL	The projections requiring the orbit inclination are OMER and SOM. INCL is the angle of inclination between the plane of the planet's equator and the plane of the satellite orbit, measured counterclockwise from the equator to the orbital plane at the ascending node. For Landsat 1,2,3 INCL=99.092, for Landsat 4,5 INCL=98.20.
ASCN	The SOM is the only projection requiring the longitude of the ascending node of the orbit.
DIST	The POIN is the only projection requiring the height, given in kilometers, above the planet.
LAT1	The OMER is the only projection requiring the latitude and longitude of two control points. These control points must be on the great circle chosen for the projection. The Mercator is a special case of the Oblique Mercator where the equator is the great circle chosen for the projection.
LON1	See LAT1
LAT2	See LAT1
LON2	See LAT1
MLIB	Maximum libration. This parameter is used only by the ALEX projection. See Hugh Kieffer for questions.
MAPROT	This parameter defines which way is up. For most projections, north is at the top when MAPROT=0. When MAPROT=90., the cube will be rotated clockwise. The valid range is -360 to 360 degrees.
PLAT	Latitude of the pole of a new spherical coordinate system. For the majority of cases, the default of no rotation is what should be used. The valid range is -90 to 90 degrees.
PLON	Longitude of the pole of a new spherical coordinate system. For the majority of cases, the default of no rotation is what should be used. The valid range is -360 to 360 degrees.
POINT1	One or two control points can be entered to define the true position of the cube when the exact latitude and longitude range are not known. If only POINT1 is used, LINE_PROJECTION_OFFSET and SAMPLE_PROJECTION_OFFSET will be corrected for any error in translation. If both points are used, MAP_SCALE, MAP_RESOLUTION and MAP_PROJECTION_ROTATION will also be corrected for any error in scale or rotation. The format for the first point is: POINT1="lat,lon,line,samp" where lat,lon,line,samp are for one known point on the cube. For example: POINT1="90.0,0.0,100.,100." defines the pole at line 100, sample 100. Note that a maximum of 10 columns may be used for each value (4F10.0). If all 10 are used, do not use a comma between the values. For example: 10 20 | | 10.123456780.1234567 100.,100. The latitude is 10.1234567 and the longitude is 80.1234567.
POINT2	The second control point must be used if there is any unknown rotation or scale change. The format for the second point is: POINT2="lat,lon,line,samp" See POINT1 for more detail.
OFFSET	The possible values for OFFSET are -360., 0. and 360. This value will be added to the center longitude and the longitude range to convert to a different coordinate range. The default of 0. will make no changes in the longitude range. This parameter can be useful when trying to mosaic a cube into a mosaic with a longitude range in a different coordinate range. (For instance, the cube ranges from 0 to 360 and the mosaic ranges from -180 to 180.) In this case, first mosaic the cube with the current labels and you will have the left half of the cube on the mosaic (0 to 180). Then run MAPLAB with OFFSET=-360, the cube will then have a longitude range of -360 to 0. Then mosaic it again and the right half of the cube (-180 to 0) will be placed in the mosaic.
KILL	This parameter will remove MAP_PROJECTION_TYPE from the labels of the cube. This causes ISIS2PICS and other programs to ignore all mapping labels. The mapping functions can be restored by rerunning MAPLAB and entering PROJ.