mls@harpo.UUCP (02/13/85)
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? Has anybody had experience with any of the computer services that offer weather briefings? What has been the cost? irv McNair ATT Bell Labs Whippany NJ
kanner@tymix.UUCP (Herb Kanner) (02/16/85)
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.