topLL_NARCS_DISTANCES Mapping, geography
Return value
a (2, n) array containing the
longitude / latitude of the resultings points. Values are in radians
unless the keyword DEGREES is set.
Parameters
lon0
in
required
lat0
in
required
arc_dist
in
required
az
in
required
Keywords
DEGREES
Examples
Result = LL_NARCS_DISTANCES(Lon, lat0, Arc_Dist, Az)
Lon_lat0 = [1.0, 2.0]; Initial point specified in radians
Arc_Dist = 2.0; Arc distance in radians
Az = 1.0; Azimuth in radians
Result = LL_ARC_DISTANCE(Lon_lat0, Arc_Dist, Az)
PRINT, Result
2.91415 -0.622234
IDL> lon0 = [-10, 20, 100]
IDL> lat0 = [0, -10, 45]
IDL> lon1 = [10, 60, 280]
IDL> lat1 = [0, 10, 45]
IDL> dist = map_npoints(lon0, lat0, lon1, lat1, azimuth = azi, /two_by_two)
IDL> earthradius = 6378206.4d0
IDL> res = ll_narcs_distances(lon0, lat0, dist/earthradius, azi, /degrees)
IDL> print, reform(res[0, *])
10.000000 60.000000 280.00000
IDL> print, reform(res[1, *])
1.1999280e-15 10.000000 45.000000
Version history
History
Based on the IDL function ll_arc_distance.pro,v 1.11 2003/02/03
Sebastien Masson (smasson@lodyc.jussieu.fr)
August 2005