Re: calculating the azimuth between two lat/lon's

*To*: mathgroup at smc.vnet.net*Subject*: [mg34790] Re: calculating the azimuth between two lat/lon's*From*: rainer <rainer.gruber at gmx.at>*Date*: Fri, 7 Jun 2002 01:08:52 -0400 (EDT)*Organization*: Johannes Kepler Universitaet Linz*References*: <adkg5p$a0h$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

rad0 wrote: > Is there a built in way to calculate the azimuth between > two points given by their latitude and longitude? > Hi rad0, I don't think that there's a "built in way" in Mathematica but you easy can calculate that angle. If we have two vectors v1 = r1 {Sin[theta1] Cos[phi1], Sin[theta1] Sin[phi1], Cos[theta1]} v2 = r2 {Sin[theta2] Cos[phi2], Sin[theta2] Sin[phi2], Cos[theta2]} (where the phi's are the longitudes and the theta's are the latitudes, measured from the z-axis) you can use the relation of the product of two vectors to get theta12, the angle between the two vectors: Solve[v1.v2 == r1 r2 Cos[theta12], Cos[theta12]] Solving and Simplifying yields something like Cos[theta12] -> Sin[theta1] Sin[theta2] Cos[phi1-phi2] + Cos[theta1] Cos[theta2] Rainer Gruber JOHANNES KEPLER UNIVERSITY LINZ Institute of Experimental Physics Atomic Physics and Surface Science