On Wednesday 25 Jun 2008 13:39, Pradeepto Bhattacharya wrote: > Hey, > > Since many people on this list have attended workshops or > even done some mapping/tracing work, I thought I would ask some > questions here - > > 1) Suppose you are walking on a particular street - 2 way > street even - you encounter a few shops - say a big Sweet and > Snacks / Hotel / School / anything, on the same street. Now how do > you put those on the maps while GPS tracking and then tracing the > map on the computer? > > I mean, the to reach the shop, you have to walk good > 5 meters or such - at times - depending on width of foot path or > such. Now those paths are not roads really, and they can vary from > place to place. How to tackle such offsets ?
GPS data is accurate to 2.5 mtr in a few, 5mtr for most under ideal conditions. Usually 10 Mtr. So you are anyway off by a few meters. For the accuracies that you are talking of you would require survey quality gps AND DGPS with correction data for your locality. > > 2) Suppose you have tracked certain part of your town or > your route from your home to airport near your city. Then you fly > to another city and then restart the GPS device. At that point the > device generally has to re-initiate itself to capture/detect the > satellites ( which it has to do anyway incase you turn off and then > switch on a gps device - atleast in some devices that I have seen > ). Anyway after it has done that, it calculates the Longitude and > Latitude and hence the current position. What happens in this case > is, the GPS device draws a straight line from City A to City B. Is > there a way to avoid that / tackle that ? That is a function of the handheld (which is a small computer with all sorts of features attached to an internal gps) not a function of the gps. You will have to check your particular handheld gps user manual on how to stop and start new traces. > Any pointers ? Thanks in advance. > > Cheers! > > Pradeepto > -- > The KDE Project : http://www.kde.org > KDE India : http://in.kde.org > Mailing List : http://mail.kde.org/mailman/listinfo/kde-india -- Rgds JTD -- http://mm.glug-bom.org/mailman/listinfo/linuxers
