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

learn more… | top users | synonyms (2)

7
votes
2answers
5k views

postprocessing GPS coordinates with RINEX data to improve precision?

Im doing some mapping for OSM in my region and I am curious if the precision of tracks from a GPS Receiver can be improved if they are post processed with RINEX data. The tracking is done with a ...
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 ...
6
votes
2answers
2k views

Trimble GeoXH vs GeoXT and GPS Correct

I am about to purchase a new GPS unit. I currently have a GeoXT and have used the combo of GPS Correct/ArcPad with GPS Analyst/ArcMap to correct the collected data to submeter (or close to it). ...
6
votes
2answers
4k views

GPS Module Without Velocity or Altitude Limitations

I am looking for a GPS module that I can use in a high-altitude project. The problem I have discovered is that GPS manufacturers are required to place a set of restrictions on GPS modules. The ...
3
votes
6answers
3k 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
375 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 ...
2
votes
1answer
6k 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
2k 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
1k 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
3answers
1k views

Using PROJ.4 library to transform from local coordinate system coordinates to global coordinate system using ground control points?

I have a point cloud whose coordinates are with respect to a local coordinate system. I also have ground control points with GPS values. Can I convert these local coordinates to a global coordinate ...
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
12k 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 ...
6
votes
1answer
2k 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 ...
6
votes
1answer
526 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 ...
5
votes
1answer
525 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 ...
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 ...
4
votes
1answer
3k views

Is there an industry-standard official mapping of GLONASS satellites to “PRN” values?

In the U.S. GPS system, satellites are uniquely identified by the PRN number broadcast by each satellite. This ID is usually visible on most GPS receiver platforms that provide access to individual ...
4
votes
0answers
249 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 ...
3
votes
1answer
193 views

Get vertice information and apply to line segments using ArcGIS for Desktop (or QGIS)?

I've recently started tracking bike treks using Strava and I thought it would be interesting to do some analysis on my treks. I am able to import the GPX file into ArcMap and convert it to a point ...
3
votes
2answers
267 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
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 ...
3
votes
1answer
254 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
4k 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 functionality,...
2
votes
0answers
45 views

Convert xyz coordinates to lon/lat to calculate height change GPS time-series data [duplicate]

How can I convert the XYZ coordinates in Lat, lon to calculate height in metric system? XYZ ascii site YYMMMDD yyyy.yyyy __MJD week d reflon _e0(m) __east(m) ____n0(m) _north(m) u0(m) ____up(m) _ant(...
2
votes
2answers
281 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 ...
5
votes
1answer
547 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
574 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 10....
3
votes
2answers
155 views

QGIS live GPS tracking /recommended hardware (GPS USB stick)

Is there a list or any other recommendation of certain GPS hardware (esp. GPS USB sticks) working with QGIS? I have been off this topic for far over a decade, and i remember that in former days not ...
3
votes
0answers
215 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 by....
3
votes
4answers
714 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 available....
2
votes
2answers
4k 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?
2
votes
1answer
203 views

Is there an industry-standard official mapping of Galileo satellites to global "PRN”/ID values?

In the U.S. GPS system, satellites are identified by the PRN number broadcast by each satellite. This ID is usually visible on most GPS receiver platforms that provide access to individual GPS ...
2
votes
1answer
111 views

Accessing GPS from QGIS 2.14.1/Python 2.7 /Windows10

I would like to access the device described at QGIS live GPS tracking /recommended hardware (GPS USB stick) via QGIS/Python. A gps module does't seem to be part of the standard installation of python ...
2
votes
4answers
255 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 ...
2
votes
1answer
543 views

GPS Live tracking with qgis android

I have a Tablet 10.1 notes on which I installed QGIS Android (v. 2.8) and a Garmin GPS 62 stc. So I tried to do the "live GPS tracking" by connecting through the USB cable the GPS to Tablet. Next, ...
2
votes
1answer
537 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
2answers
507 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
22 views

Data Transfer not working, Files to Pathfinder another way?

Typically I would use the Data Transfer Utility to retrieve files from my Trimble Geo7x and run them through GPS Pathfinder to create usable shapefiles. Currently I cannot get the transfer utility to ...
1
vote
1answer
739 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
148 views

Finding number of trips in each segment of road

I have street line layer for a city. I also have a lines travelled by the vehicle, which was created from the GPS points collected in the study (OBVIOUSLY, the path of vehicles are not accurate, so ...
1
vote
1answer
2k views

Using Python to compute the distance between coordinates (lat/long) using haversine formula and print results within .csv

I have a .csv file with 3 columns. The first column is titled Distance and it is empty. The second and third columns are titled Longitude and Latitude which contain coordinates, for example: Distance,...
1
vote
0answers
69 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
0answers
484 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
32 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
0answers
806 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
5answers
3k views

Solutions 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
508 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 ...
0
votes
0answers
166 views

How do I export sensor records from a Trimble GeoExplorer to a mapping program?

So I am fairly new with the GIS world and could use a lot of help!! I am currently surveying with a Trimble Geoexplorer 6000 XH What sort of mapping program can I use to export sensor records to ...
0
votes
0answers
246 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
346 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 ...