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MakeEllipseCoord
Compute the coordinates of an ellipse placed at a given latitude and longitude.
Usage
call MakeEllipseCoord (coord
, lat
, lon
, dec
, a_theta
, b_theta
, cinterval
, cnum
)
Parameters
coord
: output, real*8, dimension(360/cinterval
, 2)- The latitude (:,1) and longitude (:,2) coordinates of the ellipse in degrees.
lat
: input, real*8- The latitude of the center of the ellipse in degrees.
lon
: input, real*8- The longitude of the center of the ellipse in degrees.
dec
: input, real*8- Rotation angle of the semi-major axis of the ellipse in degrees with respect to local north.
a_theta
: input, real*8- The angular radius of the semi-major axis of the ellipse in degrees.
b_theta
: input, real*8- The angular radius of the semi-minor axis of the ellipse in degrees.
cinterval
: optional, input, real*8, default = 1- Angular spacing in degrees of the output latitude and longitude points. If not present, the default is 1.
cnum
: optional, output, integer- Number of elements in the output arrays.
Description
MakeEllipseCoord
will calculate the (lat, long) coordinates of an ellipse placed on a sphere at position (lat
, lon
). The semi-major and semi-minor axes, expressed in angular radii in degrees, are given by a_theta
and b_theta
, respectively. The semimajor axis of the ellipse is initially directed due north, and it is then rotated clockwise by the angle dec
. This is useful for plotting ellipses on geographic maps. The first index in the output vectors corresponds to the northern rotated semimajor axis, and subsequent points are arranged in a clockwise manner. Input and output units are in degrees.
See also
> Home > Documentation > Fortran 95 > Other
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