Post Need help !

Guys I wanted to tag images dynamically using smartphones but the problem is I need to find location coordinates of phones besides each other so that the phones can be tagged ultimately giving the owners names!!! The issue I'm facing is that I can't use GPS for it as it is giving inaccurate results. So is there any other method to do it? Like by using the radiations our phone emits or something like that!!! Please reply ASAP...Thank you so much!!

P.S. : In a scenario , suppose 4 users are in a pic and want to be automatically tagged and android phones in their pockets, so in India , gps doesn't change at such short distance !!!

I explored a lot but just cannot find a way out so posted it here