So I had an idea for a simple (probably not so simple) app for a droid or iphone (probably do android since I have a Samsung Galaxy. Basically I want to use Gps and possibly a compass on a map to get around. now heres the difference, it would be a map of a very small area with a few different buildings with different rooms(maybe 2 kms by 2 kms tops) basically im just curious if gps would be accurate enough to pinpoint a certain location on a small map for say finding a room number or something similar Basically lets say i wanted to make a map of my office building is it possible to have a phone tell me where i am with gps type in a room number with a letter infront of it ex C234 then get that app to take me there? sorry if none of this makes sence if anyone could help me out in theory id love to know
GPS will not quite be accurate enough. It will be close but not 100% down to which room you are in. Cell phone GPS uses the cell signal, which as you know is vulnerable to interference. It also travels horizontally between the tower and the cell phone; this means that it can be blocked by trees, buildings, etc. When this happens on a phone call, it might simply cause the call to drop or it might cause poor call quality. When the signal travel time is being used to calculate position, a 5 millisecond delay in transmitting the data could cause your GPS to show you 15 feet away from where you are. These are random numbers I pulled out of my ass but you get the picture. On my iPhone GPS if I zoom in far enough the GPS seems to be constantly fine-tuning the position. It gets down to which building I'm in but often shows the wrong corner of the building, etc.
You could probably accomplish what you're looking for with a WiFi positioning system (WPS) better than GPS. Check out this link for more information. Where GPS won't do, WiFi triangulation might Here's a little information from the company that holds the patents for the concept. I saw an article a few weeks ago regarding WPS enabled grocery stores, and I'm pretty sure SkyHook was behind it. Skyhook: How It Works > Overview