Question

I’ve a website where users can do checkin, so their position will be sent to server that save it and show coords on google maps…

I’m testing it with my iphone and i noticed that when the webpage request position, the iphone activate gps to retrieve coords… Is that true? (obviously i did this using 3G and not WIFI)

Ok, it works well but i’ve noticed that coords had a big margin of error or are the same of the last checkin (but the place is not the same!)

So, i thought that my iphone cached somewhere the old coords of the last checkin… Is it possible?

How can i clear the cache with jquery/javascript before do checkin?
Why the error using gps is so big? (i’ve also specified a parameter that reduce the error!)

Thanks a lot!
Enrico

Answer 1

The Geolocation API spec has a number of options related to accuracy. Look at it.

You can specify the maximum age of the fix (the spec allows caching), how long you’re willing to wait for the device to find itself, and whether you want the position to be “high accuracy” (it is not by default).