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

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13
votes
5answers
3k views

Detecting “lack of movement” on GPS device

Me and my associated are having a bit of a concept problem. We're using a GPS tracking device mounted in vehicles and later display the movements in our application. Pretty straightforward, right? ...
9
votes
2answers
188 views

How to detect traffic incidents in set of GPS traces?

I have a large database of gps traces (long, lat, timestamp) and would like to see if I can detect when congestion occurs on roads from that data. Any ideas or pointers on good algorithms to use? ...
5
votes
3answers
2k views

GPS Datalogger with USB Interface and GPX Output

I'm looking for a reliable, robust and reasonably priced GPS datalogger, to measure time, distance on tracks. The logger should be reasonably priced but ready for outdoor activities. Mud, dirt, a ...
3
votes
2answers
1k views

How to upload polygon shapefiles to my GPS?

I used QGIS to create a table (*.shp) containing 3 polygons. These polygons represent "forbidden zones" that I would like to export to my Garmin GPSmap62st so once on the countryside, I'll can see my ...
3
votes
1answer
177 views

best bluetooth gps for marine applications

What is the best gps to get as an add on for an android (asus tf300)? This is for a marine application I am writing. I need sub 5 meter accuracy. Would like decent accuracy at moderate speeds. I ...
2
votes
1answer
216 views

Keyboard shortcut for GPS data capture in QGIS

I would like to setup keyboard shortcuts for GPS data capture with QGIS. Using GPS Information dialog box, I could use Mouse-Left-Click to "Add feature" and "Add track point", but I would like to ...
1
vote
0answers
323 views

Convert GPS coordinates to EPSG:54004

I need to convert GPS coordinates to EPSG:54004 on android. Are there any libraries or formulas to acomplish the task? Thanks in advance.
3
votes
1answer
265 views

Access Trimble GPS on ArcGIS Engine App

Hopefully this isn't too obscure. I have a Trimble Yuma tablet running Windows 7. I need to build an application that allows viewing of points on a map and editing of a geodatabase (feature layers ...
8
votes
3answers
2k views

What GPS device do I need for vehicle tracking?

I am a programmer with no connection to Geographic information, except that I work on application which uses google maps. So here is my problem. I need some device, which I will be able to set in a ...
3
votes
0answers
374 views

Are there any shapefile-based GPS data recorders?

I am looking for a data recorder that can be programmed to send a serial data request to a field computer and then accept and record an incoming data string and tie it to GPS location and then save ...
2
votes
2answers
949 views

How to find the Shortest Path between two coordinates points using pgrouting A-Star?

In PostGIS I have two tables: an osm road network and a table that contains the start and end coordinate points of each path (i.e. userid, start_x1, start_y1, end_x2, end_y2). I would like to know: 1) ...
2
votes
0answers
156 views

From gpx to line segment 1Km using ArcGIS 10

I have gpx files containg points with attribute data such as time and date. I'd like to convert them into lines, and that is not a problem, but what I want to do is create 1Km segments with time and ...
2
votes
2answers
3k views

PostGIS convert geography(Point,4326) to GPS

I got a database with a column of type geography(Point,4326), the data contained looks like 0101000020E610000092E057F66EF73140930035B56CBD4840. How can I convert it to GPS coordinates?
10
votes
5answers
2k views

How to build a geographic database of GPS logs?

On our aerial wildlife surveys we typically generate dozens of GPX files, and usually convert most of them into shapefiles for display in a GIS application. GPX files are a terrific way of keeping all ...
2
votes
0answers
230 views

How would I modify GPS tracker to accept two nmea inputs and gpsmarker to include a heading vector?

I use QGIS on a research vessel and wonder whether I could modify the QGIS 1.8.0 gpsinformation widget. I want to achieve two things. 1. Change the GPS marker to a boat shape which points in the ...
0
votes
1answer
2k views

Does GPS Navigator send data to Satellite?

Does GPS Navigator send data to satellite? Is this true about regular devises available in the market?
2
votes
1answer
82 views

What operations do the GPS recievers perform after capturing signal from Satellite?

What are the operations on the signals recieved by a GPS reciever ? How does it process them towards achieving a position fix ? I need explanation with the decoding and correlating part of the ...
0
votes
0answers
176 views

MapFish Print latitude, longitude innacuracy?

I'm new to GIS so this may be trivial: I'm using MapFish Print to create some PNG. I have issues to place the viewport. When I use a random GPS coordinate: -20.904522,55.475106 which seem to point ...
7
votes
0answers
1k views

Calculating compass bearing between two GPS coordinates… with a twist [closed]

I'm building a virtual tour application that uses Google's streetview code to render the panoramas into a non-distorted view. Each panorama has 1 to n links where the user can select to move on. I ...
6
votes
1answer
354 views

Simulate (Mock) GPS Tracks

I have the following scenario: 1) I need to create GPX files for use in testing of a mobile device. 2) The tracks to be described within will span large distances over long time periods (i.e. it's ...
1
vote
2answers
395 views

QGIS GPS position after entering attributes

I would like to be able to fill a form and, before, during or after, be able to cath a GPS point. I already know the GPS extension but I have to catch the point and enter attributes after... Idea how ...
2
votes
2answers
799 views

how to make a line from a set of gps points?

As a part of my research I need to create the trajectory of respondents according to the their collected GPS data (including X and Y). I am familiar with python programming, but I am a beginner in ...
11
votes
4answers
2k views

How to filter wrong GPS points?

I have a database of GPS points. There aren't any tracks, only points. I need to calculate some value for every 100 meters, but sometimes GPS gave a wrong coordinates that lies far from real GPS ...
1
vote
0answers
211 views

Building a private GPS almanac server - practical experience

I'm trying to provide a source of GPS almanac files (in SEM format) for a non-connected / sometimes connected network. I know that I can download them from the USCG NAVCEN. However I don't want to ...
0
votes
2answers
3k views

Precision of x decimal points in meters? [duplicate]

Is there a handy reference that corelates the number of decimal points in a coordinate to the precision in meters? I had discussions like "4 decimal places will place you within a 500 meter radius" ...
2
votes
3answers
2k views

Local Coordinate to Geocentric

The ultimate question, I need a transformation matrix to take a point in local space representing a roughly 500m x 500m place in New Mexico centered at -108.619987456 long 36.234600064 lat. The final ...
4
votes
3answers
1k views

Mobile, Offline viewer for geographic data

Currently, field crews consumer geographic data via laptop (no internet, no gps). ArcReader. I would like to get them shapefiles (or some derivative of a shapefile) on a mobile platform (smartphone) ...
2
votes
1answer
138 views

interfacing multiple gps

I am trying to interface NMEA output of multiple GPS units transmitting wirelessly to a single PC, each GPS position can then be shown on georefance map of that area. My question 1.) How to ...
4
votes
2answers
408 views

Tracking a vehicle without GPS device

We are planning to write an application which have to track the user driving in his truck in the cities like New York city accurate upto which lane he was driving on. In the cities with those tall ...
4
votes
1answer
3k views

Distance calculation : Integrating incremental gps data

I am trying to build a GPS based odometer based on android. Currently , I am calculating incremental distance changes very frequently ( < 5 meter movement). The distance calculation in android is ...
1
vote
1answer
476 views

Determine if GPS coordinate in Canada

I have GPS tracking solution and most my customers in US. My reverse-geocoding solution pretty basic: Table with US ZIP database Procedure in SQL Server where I search for city/state closest to ...
1
vote
0answers
122 views

Get GPS way points to exact place

I added some GPS way points on land use layer. but way points are not in exact place.(Way points are located at little bit away from exact place) I want to adjust way points to exact place. GPS was ...
2
votes
0answers
171 views

How to enable OSM map in Garmin?

I've installed two OSM maps, but I cannot use them in Garmin. See the window of Utilities / Manage Map Products: The maps are not lockable, but I cannot use them in Garmin... What shall I do to be ...
1
vote
0answers
420 views

Importing GPS coordinates correctly

I am importing a gsx set of waypoints with lat/lon taken in degrees, minutes, and thousandths of a minute. When they are added to my project, the waypoints are not showing up correctly - the ...
2
votes
1answer
882 views

What happened to Live GPS Tracking in 1.8.0-Lisboa?

Dang, I was just getting used to Live GPS Tracking in 1.7.4-Wroclaw. I downloaded the new version 1.8.0-Lisboa on another computer. The Live GPS Tracking thing was in the View pull-down menu in ...
7
votes
3answers
650 views

GPS integration with multiple waypoint routes

I'm building a system that needs to get the output of a route optimizer into the hands of a driver who intends to make deliveries on that route. Whilst I can supply this to the driver as a printed ...
4
votes
3answers
415 views

API to suggest nearby streets

For an app I'm developing, I want to use the phone's GPS to locate it. I then want it to list streets that are nearby. The customer might be in his back garden for example, and this may be closer to ...
3
votes
0answers
737 views

How to handle real time GPS data with ArcGIS Javascript API? [closed]

I'm developing a web app using Arcgis Server 9.3.1 and Javascript API I have a database with gps data from several vehicles and I need to display each vehicle real position in a map. I display this ...
8
votes
1answer
651 views

Cleaning GPS track data

I have data captured with a GPS tracking unit. Some track have bad/cold starts and the only way to determine the track quality is by using the altitude. Unfortunately I don't have the raw GPS data and ...
3
votes
1answer
83 views

set wrong GPS unit in “degree” and want to change to “meter” in GIS while editing

I want to edit the GPS result in ArcGIS, but I found that there is a problem. I set the wrong unit while I used the GPS outside , and the unit is "degree". Although the coordinate system is correct, I ...
1
vote
2answers
3k views

How do I open a shapefile in QGIS for upload to Garmin GPSmap 62?

I now have a polygon and have succesfully raised 25 random sample points and saved as a shape file. I have checked that GPS utility and the shape file are set at 27700 BNG but when I try and open the ...
0
votes
2answers
2k views

Converting GeoExplorer gps data points

I have been given what I'm told are differential corrected gps points (DGPS) and asked to convert them to something usable in current GIS (e.g. Arcgis, Qgis). They have names like R081320a.cor, ...
1
vote
0answers
285 views

how to correct the coordinate of points [closed]

I have some a layer which contains some points. The coordinate of the points should be GPS points. However, the coordinate of these points are not correct. What should I do? I am using QGIS. If I ...
3
votes
2answers
209 views

What is the minimal data necessary to reconstruct GPS location?

Imagine that a minimal GPS device is attached to a moving object (animal, shipping container, geocache object, etc). Every few months, data from the device is downloaded for post-processing. What ...
3
votes
1answer
181 views

is the GPS network free or available for any device?

I have a question (I'm really sorry if is kind of dumb question). But if I have a device with GPS (smarthphone,pda,pocket pc, etc) Does the device need any additional service to enable GPS data? I ...
3
votes
6answers
9k views

Sending GPS Location to server

Is it possible to send my current location on iPhone or Android to the server so that others can view my current location?
5
votes
2answers
962 views

Garmin etrex 10 and QGIS

I want to know if anyone has been able to download data from a etrex 10/20/30 directly from Qgis. The usb protocol decsribe in a recent post does not do the trick. GpsBabel documentation states that ...
2
votes
1answer
599 views

Snap Polygon vertices to Point features

I have a set of polygons drawn using an inaccurate GPS PDA. these polygons are sharing nodes. after post-processing GPS data to get accurate coordinates i have a set of all the nodes, then i have to ...
12
votes
2answers
878 views

How much sense does it make to average (lat,lon) samples in order to increase 2D accuracy of a GPS location?

Several GPS applications, like this one, or this one, acquire multiple (lat,lon) samples of a given location, assuming that the GPS unit is not moving, and then take an average of the samples in order ...
2
votes
3answers
250 views

How to upload and download to gps

Do you have a step by step guide on how to upload/download points/wayponts and polylines/routes from a gps? Regards Christo