Calculate nearest GPS points near directions MySQL

Question

i have set of GPS points in database. I recently tried to select only those near to my location. I could do that with MySQL select. I use google maps to display them.

But now, i need to calculate nearest points in radius let's say 20km around directions - line segment between two gps points.

I have drawn it on a picture. I have two points A, B and i need to display only those points near to path between them.

• Yellow line is the line between A and B
• I want to select only markers in red area

http://i.stack.imgur.com/9ZbUd.jpg

Thank you for your solutions.

Answer 1

You need spherical trigonometry to calculate distances correctly on the surface of the globe. The best way is using haversines - see http://www.movable-type.co.uk/scripts/latlong.html.

Answer 2

You can calculate distances using one of functions in the following page:

Shortest distance between a point and a line segment

(if there is no mysql function you can translate some in mysql)

Then just limit your search with points that have this distance no more then you need.