[EMAIL PROTECTED] wrote: > From this data, we see it's quite possible to determine location to a > precision of around 100 x 100m or even better. > Of course this depends on the density of BTS again.
Wait ... if I understand correctly, your experiments (great, by the way ! Finally real facts ;-) indicate that you can measure some differences if moving ~50m, correct ? Now, how does this topology of relative signal strength translate to anything we can use ? Can we translate it to a geographical location ? If yes, how much error does the translation from signal path charracteristics to 3D location cause ? Also, how easily can we get the real location of the base stations ? An alternative would be to use only a topology of signal strength, and to derive hints from it. E.g., one may not be able to say that location X is 117m at 32 deg from north, but one may be able to give an estimate that it may be at 10 times the distance from the last data point, if turning 45 deg counter-clockwise. (The latter part is tricky, because one would have to project an angle between vectors in an n-dimensional space to a losely correlated 2D space.) On the way to this suggested destination, updated and hopefully more accurate directions could be generated. Of course, there will be some area where the directions are only noise. Anyway, sounds like an interesting research project. "Terrestrial navigation using GSM-based dynamic hypergeometries." :-) - Werner
