Name

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      ELL_2PT_CIRCLE

Purpose

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      Find a circle of specified radius through 2 points on an ellipsoid.

Category

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Calling Sequence

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      ell_2pt_circle, p1, p2, ref, rd

Inputs

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      p1, p2 = 2 given points. in
      ref = Reference point on circle center side. in
        Points are structures: {lon:lon, lat:lat}.
      rd = Radius of circle to fit (m). in

Keyword Parameters

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Keywords

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        CENTER=pc Returned circle center (point structure).
        /OPPOSITE means find circle with center on opposite side
          of geodesic p1 to p2 than ref point.
        /DEBUG Debug.
        NUM_ITERATIONS=cnt Returned # iterations.
        RAD2DIFF=r2d Difference of radius from p2 from rd (m).
        /BINARY use binary search method, else linear search.

Outputs

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Common Blocks

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Notes

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Modification History

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      R. Sterner, 2008 Feb 08
      R. Sterner, 2008 Feb 11 --- Added linear search.
      R. Sterner, 2009 Dec 29 --- Now tries binary if linear fails.
  Copyright (C) 2008, 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.