Hey Guys
I have a data set Air mass trajectories (excel file) with a lot of points given in decimal degrees. I have plotted the trajectories in Arcmap but I need to know the distance between them. They span more or less from equator to Greenland so there is the issue of different E/W distances.
Regards Kasper
Solved! Go to Solution.
If you do not have Desktop Advanced and the Near GP tool then provided you can deal with 0.5% error then the Haversine formula might be suitable.
Or Vincenty if you want to get fancy.
I don't work with data covering such a large area, but I would suggest km...in any event you probably want the geodesic distances which have new options in 10.2.1 perhaps using the Near tool
This must work, though I never used it
If you do not have Desktop Advanced and the Near GP tool then provided you can deal with 0.5% error then the Haversine formula might be suitable.
Or Vincenty if you want to get fancy.
Thanks for your answers.
I have tried using the Haversine formula in excel but I can’t get the right distance. I have calculated the following parameter:
R = earth’s radius (mean radius = 6,371km) | |||||
Δlat = lat2− lat1 | |||||
Δlong = long2− long1 | |||||
a = sin²(Δlat/2) + cos(lat1)*cos(lat2)*sin²(Δlong/2) | |||||
c = 2*atan2(√a, √(1−a)) | |||||
d = R*c (distance) |
As described at http://www.ig.utexas.edu/outreach/googleearth/latlong.html
It says on the web-site that angles need to be in radians and I tried with radians calculated from both decimal degrees and degrees, minutes, seconds.
I think Excel does something unusual with ATAN2.
Lat/Lon Distance Excel (Spherical Law of Cosines and Haversine Formula in Excel) | feed on my links
Now I got the Haversine fomula to work so problem solved
Thanks to all of you for your input they really helped.