Posted by Sam at May 7, 2009 08:14:04 CEST
Hi there, i want to offer online food ordering service, and i have the address list of those restaurants where they are located in difference places. The question is, when a customer input their own address, how can we compare the customer's address with our restaurant database, and give out the closest restaurant available in terms of direct distance between two points?

Thanks a lot

Sam
Posted by Steveg23 at November 28, 2010 22:17:14 CET
This is a great utility; but are the results given in true bearings or magnetic?
Posted by Jp at April 11, 2011 23:19:23 CEST
Hi, this is great utility, but is there an error in bearing calculation? No matter how short the distance is, the bearing difference between points A and B is at least one degree. My guess is that there is systematic error of one degree in the one end or another.

Cheers,
JP
Posted by Robert Lie at April 13, 2011 00:18:36 CEST
JP, thanks for noticing this error. It is now fixed.
Posted by Abdul Qadir Khan at June 1, 2011 19:09:51 CEST
how to locate the four points on google map and how to connect those points with each other so that we may print it.
for example:the distance between four sets of longitudes and latitudes coordinates result in four different points, how we can locate those four points on map.
Posted by Peter Calver at July 17, 2011 16:16:47 CEST
Magnetic North declination in the UK is approximately 1.5 deg West.
Discovered this trying to set up a TV aerial in the direction of the transmitter(s). Great site - you can look up the Post codes of the local TV transmitters on line. Put in your own and get a bearing for pointing the aerial.
Posted by Douglas Ray at August 19, 2012 10:34:12 CEST
why can I not save this to file after I have made a distance calculation. I particularly need the map in *.jpg format
Posted by Asdf at October 29, 2012 21:31:13 CET
Does anyone know if the bearings given include local declination? From Peter Calver's comment, I'm guessing not.
Posted by Pete Stephens at November 27, 2013 17:42:32 CET
Hi,

Found this site about a month back and thought brilliant - just what I have been looking for.

However I have just come to use it again over the past few days and after the initial route and bearing between two entered locations (which still works perfectly) clicking on a point on the map to re-set a location A or B comes back with undefined co-ordinates?

I have tried several PC's, Vista, XP and IE9, IE8, Chrome and FireFox and they all do the same?

Any thoughts?

Pete
Posted by Mike Ray at March 1, 2015 09:00:41 CET
Please have the option to use degrees,minutes, and seconds instead of decimal degrees. all my equipment set up this way hard to have to convert every time I use this. thanks Mike ray
Posted by Pete Stephens at July 24, 2015 13:10:37 CEST
Hi,

Am I the oly one that this stopped working for a couple of years ago?

It was brilliant and I would pay money for it but after the first calculation and display on the map selecting another point by clicking on the map and for example changing this to be location B just generates an undefined location error?

As I mentioned before this stopped woring on all browsers I have, i.e. latest versions of IE Chrome, Firefox and on a varietry of OS's XP, Vista, Win 7, Win 8.1.

It would be wondeful to have this back working :)

Regards,

Pete
Posted by Robert Lie at July 30, 2015 22:51:08 CEST
Pete,

The problem is now fixed.

The map is now using Google Map Api v3 instead of the old v1 version.
Posted by Pete Stephens at August 1, 2015 14:09:03 CEST
Hi Robert,

I just tried it and it worked and thought wow - then I saw your comment.

If nobody else appreciates your effort, I for one am ecstatic to have this back working.

Many, many thanks for reading my comment and of course fixing it :)

Regards,

Pete
Posted by Bob at December 2, 2015 00:03:00 CET
Hi, Is there a way to store Location A Latitude and Longitude data?
Posted by Alan at December 2, 2015 11:25:59 CET
Why not just give magnetic bearings. From a compass, London is not setting at 45'! which is correct my compass or your program?
Posted by Mike R at May 7, 2016 05:28:38 CEST
Magnetic readings are NOT accurate and are off by deferent amounts depending on where you are on the earth because the earths magnetic field is NOT uniform all over the world. Better accuracy is obtained by using great circle readings. Magnet bearings are only good for short distances. Your compass will be off because of the large distance to London and also the magnetic declinations at your location.
Posted by Donald Park at March 7, 2018 12:17:58 CET
Is there a way to get the topography between 2 points along the direction (for radio wave propagation) or to use UK Grid Reference points instead of having to translate to lat. and lon.
Posted by Rob Aalders at March 9, 2018 05:01:05 CET
This is a fantastic product. Is it available as an Andoid based tool so I can use it when unable connect internet. I'd happily pay for it. Rob
Posted by Craig at April 22, 2018 08:29:22 CEST
I do not understand what "true bearing" means. Can you explain this? What I am looking for is basically an antenna pointer, so I need something that says, Buffalo NY lies at 120 degrees from Hamilton ON
Posted by Jim Sutton at September 10, 2020 20:09:26 CEST
I am still seeing the one degree bearing distance issue.
It does not appear to be fixed.
Posted by Steve Sybesma at August 15, 2021 05:30:04 CEST
This has proven useful to find the shortest distance between points in the world. Using that information you can point your receiving antenna towards the broadcaster's antenna if you listen to shortwave and have a loop antenna on a rotor which is very directional.
Steve Sybesma from Brighton, CO.
Posted by Steve Sybesma at August 15, 2021 05:41:42 CEST
Craig,
You just want to pay attention to direction A because that's the direction from the starting point, assuming that is where you are.
From where you are calculating from, the destination is in direction A.
Direction B is only useful to know what your final direction is as you are arriving at the destination, because your direction slowly changes as you travel along the geodesic curved line. If someone at the destination wants to know what direction to point their antenna to you, it would be the value of your direction B plus or minus 180 degrees.
Steve Sybesma in Brighton, CO.
Posted by Steve Sybesma at August 15, 2021 06:01:14 CEST
Hello Jim,
How are you testing this?
The only way to truly test this is to calculate to a destination that is known to be directly due north or due south of you.
Your tested direction A result should end up either 0/360 or 180.
If it's still a degree off then, you will know there is a problem.
To determine accuracy, don't pick either too short a distance or the antipode of where you are now as a destination because all directions to an antipode will be the shortest distance to that point. Ideally, the best possible accuracy test would be to pick a destination that is 90 degrees of latitude north or south of where you are. If you find a discrepancy then, it needs to be fixed.
(Yes, that will in at least one of those cases put you in the opposite hemisphere.)
Doing the test this way avoids the problem of the shortest straight line distance gradually changing its direction due to a curved line veering away from a line of latitude.
The reason for due north or south and not east or west, is because calculating any other directions will force the program to calculate a geodesic since you are not at the equator. If you were at the equator, you would then be able to calculate due east or west in addition to due north or south, but never any other direction.
Steve Sybesma in Brighton, CO.
Posted by Steve Sybesma at August 15, 2021 06:53:45 CEST
Assumption, all geographic locations are correctly matched to the same LAT/LONG coordinates on all sites that show this information.

Test...calculate direction 90 degrees due north and due south of one's location to find accuracy of orthodrome direction calculation. (There is no other way I know to easily test this.)

LOCATION A: 39.9726732 / -104.8104424

Brighton, CO USA

DESTINATION IS 90 DEGREES DUE SOUTH

LOCATION B: -50.0273268 / -104.8104424

(destination: about 18 degrees longitude east of spacecraft cemetery Point Nemo in the South Pacific)

The program calculates direction correctly (predictably):

(Direction A and B are both calculated due south 180 degrees.)

This would also work with 90 degrees north (going past North Pole and arriving in eastern hemisphere near 50 north.

LOCATION B: 50.0273268 / 75.1895576

(destination: somewhere in NE Kazakhstan)

The program again calculates direction correctly (predictably):

(Direction A is calculated due north 0 degrees and Direction B is calculated due south 180 degrees.)

Steve Sybesma in Brighton, CO.
Posted by Don E at January 18, 2022 08:53:58 CET
Hi,
not sure if it can be changed, but the headings seem to always be in integer degrees. is there a way to get decimals behind the decimal point for the heading? two decimals would be very helpful.
thanks,
Don