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

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3
votes
1answer
279 views

QGIS: Colour GPS track by speed

sorry íf I might ask this question the 101 time, but I didn't found anything with google or SE. I have a CSV file with WGS84 trackpoints and visualizing them with QGIS textplugin works fine. The log ...
3
votes
1answer
309 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 ...
2
votes
1answer
4k views

How do I calculate a xyz-position of a gps-position relative to an other gps-position?

I have two gps-positions (lon, lat, alt) and want to get the position of one relative to the other one. (in meters, as x, y, z) How do I do that? Thanks in advance. Edit: The locations have a ...
8
votes
2answers
1k views

How do I group near points with GPS positions?

I'm an IT person so I don't know too much about projections and so on, I hope you can help me. I have made an application for Android that collects a GPS position, so I have the latitude and the ...
7
votes
2answers
778 views

How to Georeference Photos With No Spatial Reference?

I have about 100-200 field ground shot photos I would like to overlay in ArcGIS 10 that have no spatial information which I need to somehow develop using a photogrammetric formula. The camera was ...
7
votes
4answers
4k views

Garmin etrex raster maps support

I currently use an excellent set of printed topographic route maps for mountain biking. I would like to scan the maps, georeference them, and upload the maps to a handheld GPS device. Does the etrex ...
6
votes
1answer
407 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 ...
6
votes
1answer
1k views

How to filter wrong GPS readings?

I have absolutely no experience with GIS, it just so happens that one of the hobby projects I am doing at the local hackerspace includes tracking a model boat with a GPS... I hope this is the right ...
5
votes
1answer
82 views

How does a GPS unit ensure it has the same time reference as a GPS satellite?

I've been reading about GPS to find how it works, but one thing still bothers me. To calculate distance from GPS unit/receiver to GPS satellite, it uses the difference between radio signal sending ...
5
votes
1answer
273 views

If the GPS navigation message takes 12 1/2 minutes to cycle, how can receivers update your position every second?

According to Wikipedia's article on GPS, Each GPS satellite continuously broadcasts a navigation message... Each complete message takes 750 seconds (12 1/2 minutes) to complete. My ...
5
votes
1answer
10k views

How to batch convert Garmin GDB to GPX?

I need to convert a lot of garmin GDB files to GPX in order to convert it to another vector format. Is there any tools available can do a batch convert from garmin GDB files to GPX? Using MapSource ...
4
votes
0answers
136 views

What projection system is used in China which is aligned with WGS84 [closed]

I have some GPS tracks in Beijing. I want to project it and convert the lat long degree values in meters for calculation in euclidian space. I was wondering what is the most suitable coordinate and ...
4
votes
2answers
2k views

Trimble GeoXH, XM, XT - Data logging without Terrasync or GPSCorrect?

Is it possible to capture data for post processing on a Trimble GeoXH, XT, or XM without using Terrasync or GPScorrect? Specifically I would like to create a RINEX file. A Trimble 4000 series receiver ...
3
votes
6answers
2k views

How to clean/edit GPX (tracks) files recorded from GPS device?

During a long trip, I have recorded tracks of my journey with the GPS of my smartphone. I have ended up with about 30 GPX datafiles. Now that I am back, I am trying to draw a map of this trip. I ...
3
votes
1answer
152 views

How to calculate “stop points” from a set of GPS tracklogs?

I have a set of GPS tracks pertaining to a cycling event that happened in the same day. I don't have much geographical information about the event itself, except for the tracklogs I downloaded from a ...
3
votes
1answer
3k views

Difference between Garmin eTrex Legend HCx and eTrex 30?

I have used etrex Legend HCx a lot and been satisfied. Now I've seen etrex 30 just for a while and it seems to me that the Legend is much more user friendly, good old menus with a lot of ...
3
votes
6answers
2k views

Garmin GPS 78 Interface

Does anyone know how to interface a Garmin GPS 78 Marine GPS with their computer to manage waypoints (upload, download, save, etc.) Previously I was using the MN DNR Garmin tool, but it no longer ...
2
votes
2answers
203 views

Detecting patterns in vehicle GPS data [closed]

I need to analyze data uploaded from vehicle GPS devices to detect travel patterns and then attempt to learn about the normal travel patterns for that vehicle so that predictions can be made about ...
2
votes
0answers
238 views

how to make decent sense from scattered river depth measurements

I sampled river depth at scattered positions and I want to be able to make a map and GIS layers out of it. My problems are: As the river meanders the interpolation I do in scientific packages i,e. ...
2
votes
2answers
405 views

Vehicle tracking by QGIS

I need to do routing for a vehicle. A map with detailed turn-by-turn driving directions should be generated. For example, it should be like car race game in which the map with vehicle tracking is ...
7
votes
1answer
196 views

Unable to load .gpx file from Python Console

I'm trying to create a plugin which will extract the gpx files and load them onto the active layer window in QGIS. While I'm able to load it using the QGIS GUI from Layer>New Vector Layer, I'm not ...
5
votes
1answer
438 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 ...
4
votes
1answer
371 views

how to create a network from gps tracks?

I'm trying to build a network from several GPS-trakcs, to digitalize hiking routes on my land. I have several GPX-files from routes I've tracked with the gps. I managed to display them in Arcmap ...
3
votes
0answers
171 views

How to determine and send alert SMS for next bus stop in a GPS tracking system?

In my gps tracking system (PHP/MySql) I have got 5 Stops for a vehicle. Whenever the bus reaches stop 1, the passengers at stop 2 should get an SMS alert. And in the same way for the sops followed ...
3
votes
4answers
478 views

Why is GPS almost unavailable without a data connection?

When travelling to foreign countries, ie. when a data connection is unavailable because I don't want to spend big bucks using a roaming data connection, I noticed that GPS is virtually never ...
2
votes
2answers
315 views

Bind GNSS receiver with android app over bluetooth

I'm looking to integrate a GNSS receiver with a Smartphone app. I've found only GNSS receivers that are meant to communicate only with their mobile interface, they don't provide any documentation for ...
2
votes
1answer
254 views

Converting GPS cords to X Y based on wrapper

I'm trying to create some software for an airport and they require me to place icons of aircraft in their position based on GPS. I have 10x10 tiles each tile being 256x256 pixels and the origin point ...
2
votes
4answers
205 views

Linking up GPS points taken from rail network

Bit of a newbie here, trying to work out whether any PostGIS functions can help with my task. Apologies in advance if my use of GIS terminology is not up to scratch yet. I have a large database of ...
1
vote
2answers
209 views

Why does my phone's GPS suffer from “urban canyon” problems in Beijing but not New York?

In a separate question on Travel.SE I asked why my phone's GPS didn't seem to work in Beijing, China. Turns out that it was simply an "urban canyon" problem, and that the GPS did in fact work when I ...
1
vote
0answers
259 views

Collector for ArcGIS PDOP and GPS collection configuration settings

My company just acquired a Geneq SXBlue II GPS receiver to pair with an iPad and the Collector for ArcGIS app. The functionality is awesome and loved by everyone, but since we have biologists on our ...
1
vote
0answers
31 views

Calculate geographic position based on azimuth, distance and height [duplicate]

How to calculate the geographic position of an object in sky (Point B)(like an aircraft) from Home Point (Point A) based on only four variables: Lattitude and Longitude at Home Point, Azimuth at ...
1
vote
1answer
530 views

Using the Live tracking with internal GPS?

We have some Panasonic ToughPads (FZ-G1) with a GPS a module built in. I know where it is and can locate in it in COM 3 and it connects, registers a signal, shows satellite locations, but refuses to ...
1
vote
4answers
1k views

Cheaper solution for uploading maps to GPS (forestry maps: roads, trails, hydro, polygons)?

I'm using a QGIS 2.2.0 Valmiera on a Windows 8.1 system Desktop. I'm a forester and I would like to have a cheap solution to load maps into the handheld Garmin 60, 62 or 64 series GPS. Free would be ...
1
vote
0answers
340 views

how to combine GPS track logs using modelbuilder?

I'm creating a model to import GPS tracks(.GPX files) into ArcMap, this is to create a network of driveable off road vehicle routes. I've manage to do some of the things I'm trying to do, but there ...
1
vote
0answers
499 views

How to approximate point to segment distance on sphere?

I would like to approximate the distance of a line segment from a reference point on the map (coordinates are gives as lat/lon). In the Cartesian coordinate system I would simply find the closest ...
1
vote
0answers
74 views

What is the relationship between Map Service Instances and SDE connections?

We have a GPS project based on ArcGIS Mobile 10.0. There are two web map services and each were kept as Nonpooled with Minimum instances 15 and maximum instances 60 by original developer. The database ...
1
vote
0answers
66 views

How to measure area of polygons generated from gps data in qgis? [duplicate]

Somebody classified my question as a duplicate. But applying the answer doesn't work for me. Here is what I did: - I made sure that my layer is in a projected coordinate system (UTM30N, WGS84) - I ...
1
vote
1answer
632 views

convert GPS to x,y using reference node

i am using sensor nodes and their antenna to calculate GPS coordinates as notation of (degrees/minutes/seconds), i have some question of how to do these things: how can i convert latitude and ...
1
vote
2answers
6k views

How can I manipulate the timestamps in a GPX file?

I have a GPS tracked stored in a GPX file. Now I'm looking for a tool that allows me to set the start time of the track and the duration, and the tool should automatically evenly distribute the ...
0
votes
0answers
205 views

Can't find GPS in QGIS for Android

I have installed QGIS on my samsung galaxy note 10.1 (not 2014 edition) but I can't get contact with the GPS. I have the GPS information tool, but when I try to connect, QGIS shut down or nothing ...
0
votes
1answer
193 views

Terrasync COM Port Unavailable

I have a Trimble GeoExplorer Series GeoXM that runs Windows PocketPC version 4.2 (Built March 15 2004 for a bit more resolution there). Lately when the unit has been out on a job it will periodically ...
-1
votes
1answer
132 views

How to know the exact country or province from the longitude and latitude information automatically?

To be more specific, how to find all of point (from 1,000,000 items) located in England, or located in California? I need to process over 1,000,000 items, so a offline and automatic way is needed. ...