comp.lang.idl-pvwave archive: archive » Re: how to calculate distance from pairs of latitude/longitude measurements?

Home » Public Forums » archive » Re: how to calculate distance from pairs of latitude/longitude measurements?

Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend

Re: how to calculate distance from pairs of latitude/longitude measurements? [message #65607 is a reply to message #65606]

Wed, 11 March 2009 13:33

David Fanning
Messages: 11724
Registered: August 2001

Senior Member

llo writes:

> I tried the following formula I found in your link:
>
> Distance between points
>
> The great circle distance d between two points with coordinates
> {lat1,lon1} and {lat2,lon2} is given by:
>
> d=acos(sin(lat1)*sin(lat2)+cos(lat1)*cos(lat2)*cos(lon1-lon2 ))
>
> A mathematically equivalent formula, which is less subject to rounding
> error for short distances is:
>
> d=2*asin(sqrt((sin((lat1-lat2)/2))^2 + cos(lat1)*cos(lat2)*(sin((lon1-
> lon2)/2))^2))
>
> the result is 0.8777. 0.8777 distance from montreal to albany ????

Try MAP_2POINTS in the IDL distribution.

Cheers,

David

--
David Fanning, Ph.D.
Coyote's Guide to IDL Programming (www.dfanning.com)
Sepore ma de ni thui. ("Perhaps thou speakest truth.")

Report message to a moderator

[Message index]

		Re: how to calculate distance from pairs of latitude/longitude measurements? By: Jeremy Bailin on Thu, 12 March 2009 07:20
		Re: how to calculate distance from pairs of latitude/longitude measurements? By: mankoff on Thu, 12 March 2009 05:02
		Re: how to calculate distance from pairs of latitude/longitude measurements? By: natha on Wed, 11 March 2009 14:12
		Re: how to calculate distance from pairs of latitude/longitude measurements? By: KRDean on Wed, 11 March 2009 13:44
		Re: how to calculate distance from pairs of latitude/longitude measurements? By: David Fanning on Wed, 11 March 2009 13:33
		Re: how to calculate distance from pairs of latitude/longitude measurements? By: natha on Wed, 11 March 2009 13:21
		Re: how to calculate distance from pairs of latitude/longitude measurements? By: Bruce Bowler on Wed, 11 March 2009 13:07
		Re: how to calculate distance from pairs of latitude/longitude measurements? By: natha on Wed, 11 March 2009 12:49

Previous Topic:	Re: OpenADDE and IDL
Next Topic:	Need Help Resolving ENDIF Errors

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Sun Nov 30 22:00:03 PST 2025

Total time taken to generate the page: 2.07362 seconds