How to detect GPS hardware support in iPhone using horizontal accuracy?

in my app a user can fetch the coordinates of his/her location by either using GPS or through Forward geo-coding. the thing i want to ask is, how can i detect that the device b开发者_C百科eing used has hadware GPS support using horizontal accuracy values.??? thanking you in anticipation....

Use: https://github.com/erica/uidevice-extension