This tag refers generically to *any* space-based satellite navigation system that provides location and time information.

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3
votes
1answer
359 views

How can a single line be computed from multiple possibilities

I have datasets containing continuous GPS streams of data that represent routes or trails. For any given route, I probably have at least 5 (in some cases many more) different sets of data. Given that ...
4
votes
3answers
4k views

Measuring polyline using either QGIS or ArcGIS Desktop?

I've collected a bunch of GPS polylines (WGS84). What is the easiest way to measure the length of these lines in KM using QGIS or ArcGIS Desktop?
12
votes
3answers
383 views

Software for analyzing GPS tracklogs to extract human-readable placenames

I have a pile of GPX-formatted tracklogs for many countries where I've travelled over the years (the GPS-device has been continuously on and recording for most of the trips). I would now like to ...
6
votes
2answers
834 views

Managing error with GPS routes (theoretical framework?)

I'm looking for the appropriate theoretical framework or speciality to help me deal with understanding how to deal with the errors that the GPS system has - especially when dealing with routes. ...
3
votes
1answer
1k views

show position on google map/earth, from gps data, using google API

For those that have used google's API for mapping (google maps/earth), I would like to know if is it possible to develop an application to receive NMEA data from a gps receiver, extract position, and ...
1
vote
1answer
286 views

Converting GPS heights to AHD heights

I was wondering if there is a way to convert heights that are logged from a normal bluetooth GPS to AHD heights.
3
votes
6answers
1k views

Advantages of a GPS enabled PDA for field asset management

I'm having some trouble trying to convince some people of the advantages of having a entry level GPS enabled PDA for asset management. I've been asked to look into GPS enabled cameras, I've since ...
0
votes
3answers
242 views

Length of forms in ArcPad10

I'm trying to create a survey with about 250 questions in ArcPad 10. Normally you would expect that a form you created in any application will be able to scroll in PDA if it is too long. But the ...
3
votes
2answers
875 views

in seach of gps tracking (web) service to use with rails web app

hey out there GISers, i am looking for a gps tracking service i can hook gps devices into and request their infos via a ruby on rails webapp. does anybody know some? any help is appreciated! thanks, ...
9
votes
5answers
2k views

How can I find positions on my land?

I have about 2 acres of land, wooded and brushy. There was a survey and the corners have rebar. I am working on a site plan for house construction. I have two related problems: Finding a spot on ...
7
votes
3answers
14k views

How can I plot GPS coordinates on Google Map

What is the best way to plot GPS coordinates on a Google Map? Are there any tools that can do that (written in python specifically)?
11
votes
5answers
11k views

Convert XY points to a line?

Someone mistakenly saved a GPS track as waypoints and then sent them along to me in a .csv file. They want a line back (shapefile). What's the simplest method to convert this to a line? Available ...
2
votes
4answers
138 views

Where to license non-automotive POIs for France, Spain and Portugal?

qualified POIs are needed for a commercial project - should cover broad out-of-car usecases (not needed: parking, gas stations). Could be commercially licensable data or derived from national geodata ...
2
votes
4answers
900 views

ArcGIS Mobile that uses GPS location to route to a destination?

Does anyone know of an example of routing within ArcGIS Mobile 10 that uses GPS location to route to a destination?
6
votes
1answer
2k views

Calculating absolute precision confidence number from Dilution of Precision indicators from GPS receiver

End-user GPS receivers typically show an absolute confidence indication, such as Within 25 Metres, for the calculated position. I am parsing NMEA data from a GPS unit and wan't to calculate a similar ...
21
votes
6answers
4k views

Is GPS more accurate on specific hours of the day?

I have heard that the GPS system is more accurate, and less accurate on some specific hours on the day. If this is true, how can I get the information on when GPS is more or less accurate at my ...
7
votes
4answers
4k views

What data is sent from GPS satellites to receivers?

I know more or less how the GPS system works. But I would like to understand it in more details. Exactly what data is sent from a GPS satellite to a GPS receiver? I think there is multiple types of ...
24
votes
4answers
36k views

What are the major differences between GPS, GLONASS and Galileo?

What are the major differences between GPS, GLONASS, COMPASS and Galileo?