Sign in to follow this  
Kennair

Distance & Bearing Calculator Problem

Recommended Posts

Help from Colin or Randall (or anybody),I just downloaded the Fly Bearing & Distance Calculator and am coming up with strange results. I am trying to determine the coordinates of two runway ends given the centre position and runway length, but the result I get for Position 2 Latitude doesn't make sense. Here's the numbers and results:Position 1 - 33 22.60' & 115 40.90'Bearing - 247.5 (True)Distance - 507.5m (Half runway length of 1015m)Results:Position 2 - 33 3982.70'(!!) & 115 40.5968'As you can see the resultant latitude is certainly not a valid coordinate reference (is it?). I'm certainly doing something wrong but I don't know what. I have tried other coordinates and distances and each time the position 2 results contain a latitude with this errant figure. I have followed Colin's instructions to no avail. Can someone please help, as this tool solves lots of my country runway problems??:-hmmm:-hmmm:-hmmm Ken Brandhttp://members.optusnet.com.au/~kmbrand/mypic1.jpg"Aviation combines all the elements I love:Science, Freedom, Beauty, Adventure.As a pilot we must be at least proficient in all elements"- Charles Lindbergh.

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

Hi Ken,I didn't get the same problem?Here's what I got with your figures.

Share this post


Link to post
Share on other sites

Ah! I should have been a bit more specific, you see I left out a very important point. I live in Western Australia so my Lat/Lon are South & East respectively. When you put in these values this is what you get: (see attached)As you can see, the Latitude value for Position 2 is way off scale. Thanks Colin for your reply and I hope a resolution can be found for us in the southern hemisphere. (I still don't rule out an error on my part though).Ken Brandhttp://members.optusnet.com.au/~kmbrand/mypic1.jpg"Aviation combines all the elements I love:Science, Freedom, Beauty, Adventure.As a pilot we must be at least proficient in all elements"- Charles Lindbergh.

Share this post


Link to post
Share on other sites

Hi Ken,Yep, you're correct. It's a bug in there somewhere.However, the Fly! positions seem to be correct.I guess that the lat/long displays are not getting updated properly.So, latitude = fly lat / 3600. if you want minutes then multiply the decimal part of the answer by 60. Do it again if you want seconds.The Fly! lat and long coordinates are simply arc seconds.The latitude is counted +ve North and -ve South from the equator.The longitude is slightly different in that Fly! doesn't have East and West as such. They use an easterly longitude from 0

Share this post


Link to post
Share on other sites

Hi Ken,I've fixed it :-)As I suspected, it was a display problem with the Southern Hemisphere coordinates. The calculation was fine.I've uploaded the new version to my site for now.Check on there under 'Other Utilities'.I've tested the d/l and it worked fine for me.The zip contains new dlls as well so just copy all the new files over the old ones.Let me know if you have any more problems :-)CheersColinMy Hangar Site

Share this post


Link to post
Share on other sites

Hi Colin,Someone in another forum was trying to interpret distances between coordinates, so I recommended your calculator to them. They apparently used an online tool of some kind to convert the normal lat/lon coordinates to decimal format and came up with these numbers:Point 1: Long -87.831505, Lat 42.984665Point 2: Long -87.83128045, Lat 42.98464722These almost look like Fly! coordinates, or are they some other type of representation? Could they be entered in your Calculator, or would they have to be converted first?

Share this post


Link to post
Share on other sites

Hi Randall,They look like normal lat / longs to me.The traditional way of representing Westerly longitudes is as a negative number, the same for Southerly latitudes.To me, these would represent 87

Share this post


Link to post
Share on other sites

Thanks Colin - I converted them (via the old *60 rule) and got the same numbers you did. I'll pass on the info.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this