WCI1_XPTAN

Perform projection operations for Tan/Gnomonic (TAN) projection

Invocation

CALL WCI1_XPTAN( OP, UNPROJ, NPAR, PARAM, PROJ, STATUS )

Description

Performs conversions for the TAN projection. This is a perspective zenithal projection where the plane of projection is tangent to the sphere at the special point, and the source of the projection is the centre of the sphere.

UNPROJ are the native spherical coordinates, PROJ are the projected linearised x,y coordinates.

Arguments

• OP = INTEGER (given)
  Operation code
• UNPROJ[2] = DOUBLE (given and returned depending on OP)
  Unprojected coordinates
• NPAR = INTEGER (given)
  Number of projection parameters
• PARAM(*) = REAL (given)
  Projection parameters
• PROJ[2] = DOUBLE (given and returned depending on OP)
  Projected coordinates
• STATUS = INTEGER (given)
  The global status.

References

• WCI Subroutine Guide