Bearing Calculation

[Seth [Bell Atlantic]]

$20 to u if you can help me solve this, what I think is an easy , prob...pls
read on!
PURPOSE -- I'm trying to calculate the bearing between two given lat/long
points. I already have a calculation that works correctly that gives me the
distance between them.

The formula I'm using to get the bearing doesn't appear to be working
correctly (Supposedly, it's pulled from a 'Snyder' book.).

VIEW EQUATION/DATA/RESULTS -- If you go to
http://www.ghiek.com/php/calc_latlong.php the formula will print out to the
screen, along with the input data and resulting data from the equation at
the top of the screen.

COMMENTS:
1) there is a common point EACH place (Carnegie Hall and Carnegie Deli) is
being referenced; thus, in each data set, the lat1/long1 data points are the
same since i'm getting the bearing on 2 different occasions relative to the
lat1/long1 point

2) the result bearing is approx 57 degrees for both places but I know this
is not possible...BUT look at the last decimal places of each calculated
bearing; eg Bearing1 = 57.29579999275 and bearing2 = 57.295799919291.
Strange coincidence? I don't think so. to me, this suggests my formula is
wrong

3) note that the distance calculation appears to be working correctly since
the distances shown appear correct relative to the lat1/long1 reference
point

The first person who can straighten this out so that the bearing is returned
correctly, I'll be *happy* to drop a $20 bill in the mail. I'm not a
lat/long person so I feel i'm overlooking something obvious in the
implementation of the formula (again, displayed at the top of the url when
you go there).

thx/spirits,

seth

[Root the Mean Square]

Go here:
http://www.ngs.noaa.gov/cgi-bin/Inv_Fwd/inverse.prl
You can download the source code for this program but it's in Fortran so
you'll have to figure out what's what.

I think part of the problem might be that these three points are all real
close together and the sines and cosines of Lat and Long are going to be
very similar to each other. But it looks like you're carrying everything out
to enough places

At the same time your bearing answer keeps popping up very near the value of
1 radian, so perhaps there is a conversion that should or shouldn't be
taking place.

As far as the mechanics of the formula are concerned, all my ref books are
at the office and spherical trig was never my bestest buddy anyway.

So you're no better off than you were before. I'll be leaving now.

Cheers,
kdc

Seth [Bell Atlantic] <gh...@bellatlantic.net> wrote in message
news:10ef6.7088$5H.11...@typhoon2.ba-dsg.net...

[Mark Dinan]

try S=R*THETA(RADIANS)

"Seth [Bell Atlantic]" <gh...@bellatlantic.net> wrote in message
news:10ef6.7088$5H.11...@typhoon2.ba-dsg.net...