Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/18/84; site tymix.UUCP
Path: utzoo!utcs!lsuc!pesnta!hplabs!oliveb!tymix!kanner
From: kanner@tymix.UUCP (Herb Kanner)
Newsgroups: net.aviation
Subject: Re: Formula for distance with lat & long
Message-ID: <360@tymix.UUCP>
Date: Sat, 16-Feb-85 15:56:28 EST
Article-I.D.: tymix.360
Posted: Sat Feb 16 15:56:28 1985
Date-Received: Mon, 18-Feb-85 01:41:25 EST
References: <2666@harpo.UUCP>
Reply-To: kanner@tymix.UUCP (Herb Kanner)
Organization: Tymnet Inc., Cupertino CA
Lines: 35
Summary: 

In article <2666@harpo.UUCP> version B 2.10.2 9/18/84; site tymix.UUCP version B 2.10.1 6/24/83; site harpo.UUCP tymix!oliveb!hplabs!hpda!fortune!amdcad!decwrl!decvax!harpo!mls mls@harpo.UUCP writes:
>Some time ago, the formula for calulating the distance and
>angle between two points given the long and lat was posted.
>Could you repeat that again?
>
>
>irv McNair
>ATT Bell Labs
>Whippany NJ

The  following formulae were obtained from  a program library for the Casio
FX-602P programmable calculator.  I believe I checked them out a couple of
years ago.
              -1
	D = 60 cos   {sinN1sinN2 + cosN1cosN2cos(E2-E1)}



               -1 ( sinN2 -sin N1cos(D/60)   )
	theta = cos   (_________________________)
				  (                         )
				  (  sin(D/60)cosN1         )


	Azimuth = theta if sin(E2-E1) >= 0,
	        = 360 - theta if sin(E2-E1) < 0.

N1 and N2 are "north" latitudes.  South ones should be represented by
negative numbers.  Similarly, E1 and E2 are "west" longitudes.  East ones
should be stated as negative.  D is distance in minutes of arc, i.e.
nautical miles.

H. Kanner
Tymnet, Inc.