Name

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      ELL_CYL_EQ_AREA

Purpose

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      Compute area of given lng/lat polygon on an earth ellipsoid.

Category

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Calling Sequence

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      ell_cyl_eq_area, lng, lat, area

Inputs

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      lng, lat = Long and lat (deg). in

Keyword Parameters

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Keywords

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        LONG0=lng0 Central longitude (deg). Def=0.
        /KM return value in km^2 instead of m^2.
        /QUIET do not list area.
        NAME=name Name of area, list km^2 (over-rides /QUIET).
        /POLYGON list # pts in polygon used when listing name.
        OUT=txt Return message instead of printing it.
        /SIGNED Return signed area (no abs(area)).

Outputs

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      area = area in m^2 (-1 if error). out

Common Blocks

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Notes

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      Notes: intended for area not near a pole and not
        including a pole.
        To set the ellipsoid do ellipsoid,set=name
        Default = last set or WGS 84 if none set.

Modification History

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      R. Sterner, 2002 May 06
      R. Sterner, 2002 May 07 --- Added new keyword KM.
      R. Sterner, 2006 Feb 13 --- Added NAME=name, /POLYGON.
      R. Sterner, 2006 Feb 13 --- Added OUT=txt.
      R. Sterner, 2010 May 04 --- Converted arrays from () to [].
  Copyright (C) 2002, Johns Hopkins University/Applied Physics Laboratory
  This software may be used, copied, or redistributed as long as it is not
  sold and this copyright notice is reproduced on each copy made. This
  routine is provided as is without any express or implied warranties
  whatsoever. Other limitations apply as described in the file disclaimer.txt.