I noticed that GSMLoc locks a location faster and slightly more accurately then GPS, is it always preferable to use GSMLoc over GPS if it is available? Would there be any reason to use GPS over GSMLoc, besides if a cell network isn't available?
Hi,
I don't have an answer for you but was wondering how you know one is more "accurate" than the other?
GSMLoc returns coordinates of a cell tower your cellular device has registered to, accuracy goes from worse to worst when the device gets far away from the cell site
GSMLoc returns coordinates of a cell tower your cellular device has registered to
So, it's probably pretty "accurate" since the cell phone company presumably knows exactly where the tower is, and it never moves.
besides if a cell network isn't available?
You also don't need a cell phone account. ...I've got a Garmin and there are no monthly fees.
jpom:
Hi,I don't have an answer for you but was wondering how you know one is more "accurate" than the other?
Well for one thing, it doesn't really seem to be suffering from drift like the GPS does... And also yea it moves when I move and is pretty close to the GPS outputs, give or take 0.5 degrees.
DVDdoug:
So, it's probably pretty "accurate" since the cell phone company presumably knows exactly where the tower is, and it never moves.![]()
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You also don't need a cell phone account. ...I've got a Garmin and there are no monthly fees.
So what exactly is GSMLoc, I thought it was through a cell network, or at least GSM? I can't really seem to find anything on it through just googling.
I had assumed that GSM Location fixing used triangulation from nearby phone towers.
I can see how in some situations, that will lead to a faster location fix than a conventional GPS. There might also be situations, when GPS reception is poor for instance, that it gives a more accurate location fix.
However, if a GPS is working with a good view of the sky, I dont understand how GSMloc would improve on the standalone GPS fix.
kristofp12:
So what exactly is GSMLoc, I thought it was through a cell network, or at least GSM? I can't really seem to find anything on it through just googling.
if this is what you referring to
+cipgsmloc:
0,longitude,latitude,date,time
it USES data(internet), or else you get error 601
i am sort of sure it returns a base station's location, not the mobile station's
i have several gsm based devices (kind of water dispensers ) ,
when send 'location' as SMS to it, it returns the cipgsmloc response as it should
but when i plug them into a online mapping software, well, the location is like 500 to 700m ( more or less closer to the BTS ) from the MS
never gets below 400m and i am not sure if it does triangulation either, may be we got few cell sites around in here
the simcom AT doc barely explains about the 'at+cipgsmloc'
I just Googled "GSMLoc GPS". First reference is to this very Arduino forum discussion!
If your GPS position differs from your map by 100s of metres I wonder if you need to consider the local GPS datum used by the map maker. I don't know much about this but there is such a concept and the local mapping regulator has to update their datum from time to time.
The drift of position with a GPS is perhaps simply honestly reflecting the difficulties involved in computing position. If the position determined with assistance from the cell network does not drift, some algorithm within the whole system may be filtering out the drift -- perhaps giving a rolling average of the last 5 measurements. Practical, but not necessarily more accurate.
The algorithms used by the companies involved are probably proprietary and not made public. How can the user ever really compare accuracies from differrent devices? What is our master reference? The cell towers? But somebody had to determine their position. How? Probably a GPS. How do we know how accurate that measurement was?
I think we have to think about what we need from this concept of "accuracy" for our application.
John.