MODULE MODGCTP. Note that SETPROJ()
is generic, taking either single-precision or double-precision arguments.
NOTES for prior I/O API versions:
LAMBERT()is the main function-body, and the rest exceptLL2UTM())andUTM2LL()are allLOGICAL ENTRYinto this function, rather than stand-alone subroutines.For I/O API Version 3.1, explicit
INTERFACEs are given inMODULE M3UTILIO, andLL2ALB()andALB2LL()are the only Albers-projection functions available.For I/O API versions prior to 3.1, they need explicit
EXTERNALdeclarations, and the Albers-projection functions are not available.
LOGICAL FUNCTION LAMBERT( CNAME, A, B, C, XC, YC )
LOGICAL FUNCTION POLSTE( CNAME, A, B, C, X, Y )
LOGICAL FUNCTION TRMERC( CNAME, A, B, C, X, Y )
LOGICAL FUNCTION EQMERC( CNAME, A, B, C, X, Y )
LOGICAL FUNCTION ALBERS( CNAME, A, B, C, X, Y )
LOGICAL FUNCTION INITPROJ( CNAME )
LOGICAL FUNCTION INITPROJ( CNAME, CTYPE, AA, BB, CC, XX, YY )
LOGICAL FUNCTION INITPROJ( CNAME, CTYPE, DA, DB, DC, DX, DY )
LOGICAL FUNCTION SETPROJ( CNAME, CTYPE, A, B, C, XC, YC )
LOGICAL FUNCTION SETPROJ( CNAME, CTYPE, D, E, F, XD, YD )
LOGICAL FUNCTION SETLAM( A, B, C, X, Y )
LOGICAL FUNCTION SETPOL( A, B, C, X, Y )
LOGICAL FUNCTION SETTRM( A, B, C, X, Y )
LOGICAL FUNCTION SETEQM( A, B, C, X, Y )
LOGICAL FUNCTION SETALB( A, B, C, X, Y )
LOGICAL FUNCTION LL2LAM ( X, Y, U, V )
LOGICAL FUNCTION LL2UTM ( X, Y, Z, U, V )
LOGICAL FUNCTION LL2POL ( X, Y, U, V )
LOGICAL FUNCTION LL2TRM ( X, Y, U, V )
LOGICAL FUNCTION LL2EQM ( X, Y, U, V )
LOGICAL FUNCTION LL2ALB ( X, Y, U, V )
LOGICAL FUNCTION LAM2LL ( X, Y, U, V )
LOGICAL FUNCTION LAM2UTM( X, Y, Z, U, V )
LOGICAL FUNCTION LAM2POL( X, Y, U, V )
LOGICAL FUNCTION LAM2TRM( X, Y, U, V )
LOGICAL FUNCTION LAM2EQM( X, Y, U, V )
LOGICAL FUNCTION LAM2ALB( X, Y, U, V )
LOGICAL FUNCTION UTM2LL ( X, Y, Z, U, V )
LOGICAL FUNCTION UTM2LAM( X, Y, Z, U, V )
LOGICAL FUNCTION UTM2POL( X, Y, Z, U, V )
LOGICAL FUNCTION UTM2TRM( X, Y, Z, U, V )
LOGICAL FUNCTION UTM2EQM( X, Y, Z, U, V )
LOGICAL FUNCTION UTM2ALB( X, Y, Z, U, V )
LOGICAL FUNCTION POL2LL ( X, Y, U, V )
LOGICAL FUNCTION POL2LAM( X, Y, U, V )
LOGICAL FUNCTION POL2UTM( X, Y, Z, U, V )
LOGICAL FUNCTION POL2TRM( X, Y, U, V )
LOGICAL FUNCTION POL2EQM( X, Y, U, V )
LOGICAL FUNCTION POL2ALB( X, Y, U, V )
LOGICAL FUNCTION TRM2LL ( X, Y, U, V )
LOGICAL FUNCTION TRM2LAM( X, Y, U, V )
LOGICAL FUNCTION TRM2UTM( X, Y, Z, U, V )
LOGICAL FUNCTION TRM2POL( X, Y, U, V )
LOGICAL FUNCTION TRM2EQM( X, Y, U, V )
LOGICAL FUNCTION TRM2ALB( X, Y, U, V )
LOGICAL FUNCTION EQM2LL ( X, Y, U, V )
LOGICAL FUNCTION EQM2LAM( X, Y, U, V )
LOGICAL FUNCTION EQM2UTM( X, Y, Z, U, V )
LOGICAL FUNCTION EQM2POL( X, Y, U, V )
LOGICAL FUNCTION EQM2TRM( X, Y, U, V )
LOGICAL FUNCTION EQM2ALB( X, Y, U, V )
LOGICAL FUNCTION ALB2LL ( X, Y, U, V )
LOGICAL FUNCTION ALB2LAM( X, Y, U, V )
LOGICAL FUNCTION ALB2UTM( X, Y, Z, U, V )
LOGICAL FUNCTION ALB2POL( X, Y, U, V )
LOGICAL FUNCTION ALB2TRM( X, Y, U, V )
LOGICAL FUNCTION ALB2EQM( X, Y, U, V )
REAL , INTENT(IN ) :: A ! first secant latitude, or P_ALPHA
REAL , INTENT(IN ) :: B ! second secant latitude B > A, or P_BETA
REAL , INTENT(IN ) :: C ! central meridian, or P_GAMMA
REAL , INTENT(IN ) :: XC ! Longitude of Cartesian origin
REAL , INTENT(IN ) :: YC ! Latitude of Cartesian origin
REAL , INTENT(IN ) :: X ! (Input) Cartesian easting in meters or decimal degrees
REAL , INTENT(IN ) :: Y ! (Input) Cartesian northing "
REAL , INTENT(IN ) :: U ! (Output) Cartesian easting "
REAL , INTENT(IN ) :: V ! (Output) Cartesian northing "
REAL*8 , INTENT(IN ) :: D ! first secant latitude, or P_ALPHA
REAL*8 , INTENT(IN ) :: E ! second secant latitude B > A, or P_BETA
REAL*8 , INTENT(IN ) :: F ! central meridian, or P_GAMMA
REAL*8 , INTENT(IN ) :: XD ! Longitude of Cartesian origin
REAL*8 , INTENT(IN ) :: YD ! Latitude of Cartesian origin
INTEGER, INTENT(IN ) :: Z ! UTM zone (1...36)
REAL , INTENT( OUT) :: AA ! first secant latitude, or P_ALPHA
REAL , INTENT( OUT) :: BB ! second secant latitude B > A, or P_BETA
REAL , INTENT( OUT) :: CC ! central meridian, or P_GAMMA
REAL , INTENT( OUT) :: XX ! Longitude of Cartesian origin
REAL , INTENT( OUT) :: YY ! Latitude of Cartesian origin
REAL , INTENT( OUT) :: DA ! first secant latitude, or P_ALPHA
REAL , INTENT( OUT) :: DB ! second secant latitude B > A, or P_BETA
REAL , INTENT( OUT) :: DC ! central meridian, or P_GAMMA
REAL*8 , INTENT( OUT) :: DX ! Longitude of Cartesian origin
REAL*8 , INTENT( OUT) :: DY ! Latitude of Cartesian origin
REAL single precision
(unlike the double precision used internally by GCTP).
Calculations for which precision is important should use
GCTP or MODULE M3GCTP routine
XY2XY() directly; further note that by default,
LAMBERT() etc., use the GRS 1980 spheroid to
represent the surface of the Earth (which may be important to know
for high-precision calculations). For use in SMOKE and legacy
applications, or where precision is not important. Otherwise use
MODULE M3GCTP routine XY2XY()
INITPROJ(), LAMBERT(), POLSTE(),
TRMERC(), EQMERC(), and
ALBERS() set up USGS National Mapping Division General
Cartographic Transformation Package, routine
GTPZ0() by
map-projection name for particular named
Lambert Conformal Conic, Polar Stereographic, Transverse Mercator,
Equatorial Mercator, or Albers Equal-Area Conic projections,
respectively. If CNAME is the grid name, the
subroutine returns the corresponding coordinate system
name, and coordinate definition parameters
A,B,C,X,Y. (or equivalent REAL*8
projection parameters. The resulting projection will be used
by subsequent calls of that type -- e.g., if the projection is
Lambert, by LAM2LL(), LL2LAM(),, etc.
SETPROJ(), SETLAM(),
SETPOL(), SETTRM(), SETEQM(),
and SETALB() set up GTPZ0()
according to map-projection parameters supplied as
arguments, for anonymous Lambert Conformal Conic, Polar
Stereographic, Transverse Mercator, Equatorial Mercator, or Albers
Equal-Area Conic projections, respectively. The resulting
projection will be used by subsequent calls of that type -- e.g., if
the projection is Lambert, by LAM2LL(), LL2LAM(),, etc.
See also:
the usage-manual section on horizontal coordinates and grids for more about I/O API grid and coordinate system conventions.routines
LL2UTMandUTM2LL.
USGS package GCTP
MODULE MODGCTPand its routinesGRID2XY()andXY2XY()
LAMBERT(), POLSTE(), TRMERC(), EQMERC(), or
ALBERS(), CNAME must be the name either
of a coordinate system or a grid found in file
GRIDDESC; furthermore, the projection-type of that
coordinate system must be respectively LAMGRD3 (i.e.,
Lambert Conformal Conic), POLGRD3 (Polar Stereographic),
TRMGRD3 (Transverse Mercator), EQMGRD3
(Equatorial Mercator), or ALBGRD3 (Albers Equal-Area
Conic) respectively.
You must call LAMBERT() or SETLAM()
before calling conversion functions with Lambert input or output
coordinates; likewise POLSTE() or
SETPOL(), TRMERC() or
SETTRM(), EQMERC() or SETEQM(), or
ALBERS() or SETALB()before calling
coordinate-transform functions for respectively Polar
Stereographic, Transverse Mercator, Equatorial Mercator, or Albers
Equal-Area Conic.
CNAME has length at most 16.
If named map projections are specified by LAMBERT(), POLSTE(),
TRMERC(), EQMERC(), or ALBERS(), then a file
with logical name
GRIDDESC exists and contains
correctly formatted coordinate system descriptions and grid
descriptions.
USE MODGCTP
For version 3.1:
USE M3UTILIO
For version 3.0 or earlier. declare explicitly:
LOGICAL, EXTERNAL :: LAMBERT, LL2LAM, LAM2LL
[etc...]
then:
...
LOGICAL LAMSET, POLSET
REAL A, B, C, X, Y
REAL XX, YY, UU, VV
CHARACTER*16 LAMNAME
...
LAMSET = LAMBERT( LAMNAME, A, B, C, X, Y )
...
Y = GETREAL( -90.0, 90.0, Y, 'Enter origin latitude YCENT' )
POLSET = SETPOL( A, B, C, X, Y )
...
YY = GETREAL( -9.0E12, 9.0E12, Y, 'Enter input Y coordinate' )
IF ( LAM2POL( XX, YY, UU, VV ) ) THEN
WRITE( *, 2( 5X, A, 1PE14.6, A, 1PE14.6, A, / )' )
& 'Lambert X=', XX, ' : Y=', YY, ' (meters)',
& 'POL X=', UU, ' : Y=', VV, ' (meters)'
...
END IF
...
(See sample programs LATLON, PRESZ, or UTMTOOL, for usage examples.)
Up: Coordinate and Grid Related Routines
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