2009/9/24 Dan O'Hara <detect...@yahoo.com.au>: > From what I've read I now will go back to source=survey and add the tag > survey=gps. I will consider further the advantages of further definition to > GPS type (I think that could well end up in a Commodore/Falcon and > Landcruiser/Patrol debate).
Not really, cars have had over 120 years to get to this point in time, electronics is much less mature and there is significant differences between the GPS chipset in iPhones which does poorly compared to some other phones, then you have various dedicated GPS devices some of which would be more accurate than others, and you have current technology verses older technology all of which can decrease acuracy compared to other devices. I've played with 3 different phones with GPS some were better than others, and if they had 3G coverage/capability they were more accurate again. I've also played with a couple of GPS loggers, one of which is more accurate than the phones, the other is much worst. Then you get into DGPS like Ross suggested, you also have devices that can mostly lock onto the secondary GPS frequency which gives the device more certainty by being able to work out the atmospheric conditions better. You also have the farming GPS stuff which is good down to the 4cm or sub-cm accuracy levels. It's all about how much money you have to burn but there is significant differences between technologies for various reasons. _______________________________________________ Talk-au mailing list Talk-au@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-au
