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

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12
votes
2answers
463 views

Why does GPS altitude jump sometimes?

I am currently developing a little application in Android which uses GPS. When i click a button i start to record a "track". If i walk around i save my position every second into a file. This works ...
3
votes
0answers
228 views

QGIS: GPS Tracking with improved Altitude

I am preparing for archeological fieldwork in Sudan. I recently came up with RTK equipment and software using RTKlib to export the real time corrected data (cm level) to QGIS via a simulated NMEA ...
1
vote
1answer
1k views

GPS data validation

I was wondering if Fix quality data from GPGGA, can be substituted to Validity field in GPRMC? In my application I have to use only GPRMC, but I don't really know if it sets validity only if Fix ...
2
votes
3answers
4k views

Can *.ssf files from Trimble GPS be imported as features to display in ArcMap?

I have not come across *.ssf files before but I believe they are a Trimble GPS binary format. Someone has asked me if these files which he thinks have line/poly features can be imported for display ...
19
votes
6answers
3k views

How to create a polyline-based “heatmap” from GPS tracks?

This winter I am planning to track my downhill skiing/snowboarding using a GPS. Most of my riding will occur at the same resort. I would like to be able to create a sort of "heatmap" that shows the ...
3
votes
0answers
163 views

Are there any known problems using GPS connection in Android version of QGIS? [closed]

I install QGIS both my netbook (windows win7 starter) and My tablet (android 4.0). I can used GPS option in windows version and I can save location points from GPS. However, I could not manage same ...
7
votes
3answers
1k views

Register and display real time tracking of my smartphone (gps) on a map

I have 2 smartphones (android galaxy and iphone) and i would like to display the position, according to the gps coordinates, on a map. Is there any app to download or any kind of service where i ...
2
votes
1answer
70 views

calibrating vector line in qgis

I have loaded GPS points into a QGIS vector layer. I also imported a vector line from a dxf file which doesn't have georeferencing. I would like to fit in line geometry between the GPS points - how ...
6
votes
1answer
170 views

GIS Server for web service

I am building an app that has some GIS requirements that go a little beyond (I think) what I can retrieve from existing online web services resources so I am attempting to build a server of my own to ...
0
votes
0answers
994 views

How does a GPS/GSM/GPRS Tracker work without a monthly fee?

GPS newbie here. Looking at this product: http://dx.com/p/gps-gsm-gprs-tracker-for-personal-remote-positioning-29284 How does a GPS tracker work without a monthly plan? Thank You.
7
votes
3answers
5k views

Accessing GPS data with JavaScript in real time

Is it possible to access GPS data in real time on a smartphone with JavaScript (without an android or ios application I mean)? Thanks
1
vote
0answers
28 views

Creation of 3d terrain from real data [duplicate]

Possible Duplicate: 3d terrain from data in postgres I am pretty new to spatial database and 3D data. I have a project where i have to create a 3d terrain from data being taken by me by a ...
4
votes
1answer
590 views

How to show a geoTiff on an iOS application?

I'm developing an iOS application that will use offline maps. These maps are on GeoTiff format but I don't know how to do it. I've found this question: How to display a GeoTIFF on mapView but it uses ...
5
votes
1answer
389 views

How to connect particular sets of points with (poly)lines?

I think my problem is quite easy to be solved by the most postgis-users, but i am a bloody beginner: i have a timestamped point-table representing GPS-tracked places of different cars. To distinguish ...
2
votes
1answer
128 views

Pathfinder Differential Correction: “Use reference position from” who?

How do you choose either "base files" or "base provider"?
1
vote
1answer
310 views

Small Idea to get best path between two points

Guys I don't know if its a good place to post ideas or to ask general questions. Still as the question is related with maps service, I am posting it here. If it's not the right place, please move me ...
1
vote
1answer
445 views

Can i use GPS Garmin GPSmap 62s in GIS projects with high accuracy?

i have GPS Garmin GPSmap 62s, is this can be dependable in GIS projects with high accuracy, and what is the "RMS", the minimum error rate in meter, and can i linking it with arcpad to draw road or ...
7
votes
3answers
321 views

How to improve positioning of images taken with GPS and Gyro info?

I'm sort of 'recreating' google street view with MIT right now. We have a car with a camera on top and we're driving at 10mph down a road. As we drive we're shooting pictures at 30fps and each photo ...
2
votes
0answers
160 views

QGIS on android4 with bluetooth GPS

I'm trying to set up a moving map on my tablet (asus, Android 4). I've installed QGIS (latest version), which works. I've got a blue tooth external GPS, which I've paired to the tablet. However, I ...
1
vote
1answer
2k views

GPS units compatible with Galileo

It seems like after lots of initial problems Galileo project is taking off (ESA, BBC). I was wondering what the state of preparation for that is on hardware side. Are there any consumer grade GPS ...
7
votes
4answers
7k views

Using android phone to plot GPS points?

I was wondering if I could use my android phone (HTC Wildfire) to plot gps points and export these into GIS software (I have QGIS and MapInfo). Thanks, Alan
13
votes
5answers
2k 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
184 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
1k 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
176 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
205 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
309 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
256 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
371 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
911 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
152 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
2k 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?
9
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
222 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
81 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
173 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 ...
6
votes
1answer
332 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
372 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
751 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
203 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
2k 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
135 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
403 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
2k 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 ...