This post is related to search around a particular latitude and longitude for a given radius in Km or Miles.
- One degree of latitude is equal to about 69 or 70 miles or 111 Km.
- Suppose you have to search in a circle of 4 miles ,the center of the the circle is lat,long you have.
- Since 70 miles is equal to 1 degree lat then the latitude radius will be “4/70=0.057″ .
- now suppose the center point lat, long is:latitude=26.262011,longitude=81.546562 then the range will be in which you have to search will be
- minLat=26.262011- 0.057
- maxLat=26.262011+ 0.057
- minLong=81.546562 – 0.057
- maxLong=81.546562 + 0.057
- Now you can run a sql query to database with between statement like:- where latitude between “this” and “this” and longitude between “this” and “this” .
- It will give you all the location’s lat ,long that are in that 4 miles circle around given lat long center point.
- Some Resources for Understanding latitude and Longitude:
- http://www.infoplease.com/homework/latlongfaq.html
- http://www.infoplease.com/ipa/A0908193.html
- http://www.hammondmap.com/catalog/classroom_activities/latlong1.html
Authors bio is coming up shortly. 
Just the info I was looking for, thanks!