Procedure

   void latsph_c ( SpiceDouble    radius,
                   SpiceDouble    lon,
                   SpiceDouble    lat,
                   SpiceDouble *  rho,
                   SpiceDouble *  colat,
                   SpiceDouble *  lons )

Abstract

   Convert from latitudinal coordinates to spherical coordinates.

Required_Reading

   None.

Keywords

   CONVERSION,  COORDINATES

Brief_I/O

   VARIABLE  I/O  DESCRIPTION
   --------  ---  --------------------------------------------------
   radius     I   Distance of a point from the origin.
   lon        I   Angle of the point from the XZ plane in radians.
   lat        I   Angle of the point from the XY plane in radians.
   rho        O   Distance of the point from the origin.
   colat      O   Angle of the point from positive z axis (radians).
   lons       O   Angle of the point from the XZ plane (radians).

Detailed_Input

   radius     Distance of a point from the origin.

   lon        Angle of the point from the XZ plane in radians.

   lat        Angle of the point from the XY plane in radians.

Detailed_Output

   rho        Distance of the point from the origin.

   colat      Angle between the vector from the origin to the point
              and the positive z axis in radians. `colat' is computed
              as pi/2 - `lat'.

   lons       Angle of the point from the XZ plane (radians). `lons'
              is set equal to `lon'.

Parameters

   None.

Exceptions

   Error free.

Files

   None.

Particulars

   This routine returns the spherical coordinates of a point
   whose position is input in latitudinal coordinates.

   Latitudinal coordinates are defined by a distance from a central
   reference point, an angle from a reference meridian, and an angle
   above the equator of a sphere centered at the central reference
   point.

   Spherical coordinates are defined by a distance from a central
   reference point, an angle from a reference meridian, and an angle
   from the z-axis.

Examples

   Co-latitude is obtained by subtracting latitude from HALFPI()
   Radius and longitude mean the same thing in both latitudinal
   and spherical coordinates.  The table below lists lat
   corresponding lat in terms of degrees.

           lat            lat
          ------         ------
            0             90
           20             70
           45             45
          -30            120
           90              0
          -45            135

Restrictions

   None.

Literature_References

   None.

Author_and_Institution

   W.L. Taber      (JPL)

Version

   -CSPICE Version 1.0.2, 26-JUL-2016 (BVS)

      Minor headers edits.

   -CSPICE Version 1.0.1, 13-DEC-2005   (EDW)

      Corrected typo in Deatiled_Output, substituted
      "colat" for "lat."

   -CSPICE Version 1.0.0, 08-FEB-1998   (EDW)

Index_Entries

   latitudinal to spherical coordinates

Link to routine latsph_c source file latsph_c.c