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/***************************************************************************/
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/* RSC IDENTIFIER: MERCATOR
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* This component provides conversions between Geodetic coordinates
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* (latitude and longitude in radians) and Mercator projection coordinates
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* (easting and northing in meters).
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* This component checks parameters for valid values. If an invalid value
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* is found, the error code is combined with the current error code using
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* the bitwise or. This combining allows multiple error codes to be
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* returned. The possible error codes are:
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* MERC_NO_ERROR : No errors occurred in function
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* MERC_LAT_ERROR : Latitude outside of valid range
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* (-89.5 to 89.5 degrees)
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* MERC_LON_ERROR : Longitude outside of valid range
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* (-180 to 360 degrees)
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* MERC_EASTING_ERROR : Easting outside of valid range
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* (False_Easting +/- ~20,500,000 m,
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* depending on ellipsoid parameters
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* and Latitude_of_True_Scale)
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* MERC_NORTHING_ERROR : Northing outside of valid range
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* (False_Northing +/- ~23,500,000 m,
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* depending on ellipsoid parameters
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* and Latitude_of_True_Scale)
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* MERC_LAT_OF_TRUE_SCALE_ERROR : Latitude of true scale outside of valid range
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* (-89.5 to 89.5 degrees)
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* MERC_CENT_MER_ERROR : Central meridian outside of valid range
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* (-180 to 360 degrees)
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* MERC_A_ERROR : Semi-major axis less than or equal to zero
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* MERC_INV_F_ERROR : Inverse flattening outside of valid range
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* MERCATOR is intended for reuse by any application that performs a
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* Mercator projection or its inverse.
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* Further information on MERCATOR can be found in the Reuse Manual.
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* MERCATOR originated from : U.S. Army Topographic Engineering Center
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* Geospatial Information Division
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* Alexandria, VA 22310-3864
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* None apply to this component.
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* MERCATOR has no restrictions.
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* MERCATOR was tested and certified in the following environments:
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* 1. Solaris 2.5 with GCC, version 2.8.1
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* 2. Windows 95 with MS Visual C++, version 6
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* 10-02-97 Original Code
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* 03-18-08 Changed 'origin latitude' to 'latitude of true scale'
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/***************************************************************************/
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#define MERC_NO_ERROR 0x0000
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#define MERC_LAT_ERROR 0x0001
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#define MERC_LON_ERROR 0x0002
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#define MERC_EASTING_ERROR 0x0004
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#define MERC_NORTHING_ERROR 0x0008
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#define MERC_LAT_OF_TRUE_SCALE_ERROR 0x0010
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#define MERC_CENT_MER_ERROR 0x0020
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#define MERC_A_ERROR 0x0040
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#define MERC_INV_F_ERROR 0x0080
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/***************************************************************************/
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/* ensure proper linkage to c++ programs */
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long Set_Mercator_Parameters(double a,
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double Latitude_of_True_Scale,
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double Central_Meridian,
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double False_Easting,
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double False_Northing,
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double *Scale_Factor);
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* The function Set_Mercator_Parameters receives the ellipsoid parameters and
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* Mercator projcetion parameters as inputs, and sets the corresponding state
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* variables. It calculates and returns the scale factor. If any errors
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* occur, the error code(s) are returned by the function, otherwise
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* MERC_NO_ERROR is returned.
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* a : Semi-major axis of ellipsoid, in meters (input)
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* f : Flattening of ellipsoid (input)
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* Latitude_of_True_Scale : Latitude in radians at which the (input)
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* point scale factor is 1.0
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* Central_Meridian : Longitude in radians at the center of (input)
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* False_Easting : A coordinate value in meters assigned to the
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* central meridian of the projection. (input)
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* False_Northing : A coordinate value in meters assigned to the
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* origin latitude of the projection (input)
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* Scale_Factor : Multiplier which reduces distances in the
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* projection to the actual distance on the
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void Get_Mercator_Parameters(double *a,
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double *Latitude_of_True_Scale,
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double *Central_Meridian,
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double *False_Easting,
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double *False_Northing,
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double *Scale_Factor);
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* The function Get_Mercator_Parameters returns the current ellipsoid
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* parameters, Mercator projection parameters, and scale factor.
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* a : Semi-major axis of ellipsoid, in meters (output)
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* f : Flattening of ellipsoid (output)
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* Latitude_of_True_Scale : Latitude in radians at which the (output)
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* point scale factor is 1.0
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* Central_Meridian : Longitude in radians at the center of (output)
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* False_Easting : A coordinate value in meters assigned to the
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* central meridian of the projection. (output)
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* False_Northing : A coordinate value in meters assigned to the
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* origin latitude of the projection (output)
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* Scale_Factor : Multiplier which reduces distances in the
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* projection to the actual distance on the
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long Convert_Geodetic_To_Mercator (double Latitude,
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* The function Convert_Geodetic_To_Mercator converts geodetic (latitude and
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* longitude) coordinates to Mercator projection easting, and northing
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* coordinates, according to the current ellipsoid and Mercator projection
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* parameters. If any errors occur, the error code(s) are returned by the
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* function, otherwise MERC_NO_ERROR is returned.
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* Latitude : Latitude (phi) in radians (input)
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* Longitude : Longitude (lambda) in radians (input)
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* Easting : Easting (X) in meters (output)
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* Northing : Northing (Y) in meters (output)
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long Convert_Mercator_To_Geodetic(double Easting,
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* The function Convert_Mercator_To_Geodetic converts Mercator projection
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* easting and northing coordinates to geodetic (latitude and longitude)
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* coordinates, according to the current ellipsoid and Mercator projection
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* coordinates. If any errors occur, the error code(s) are returned by the
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* function, otherwise MERC_NO_ERROR is returned.
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* Easting : Easting (X) in meters (input)
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* Northing : Northing (Y) in meters (input)
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* Latitude : Latitude (phi) in radians (output)
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* Longitude : Longitude (lambda) in radians (output)
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#endif /* MERCATOR_H */
added
removed
dt_cc/mercator/mercator.h
