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

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5
votes
1answer
409 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
73 views

How to find if two gps tracks were from the same trip?

Given I have gps tracks from many users running or hiking, how can I find out who were running together? In other words, which algorithms are there to find out who were in the same party? Haven't ...
12
votes
2answers
500 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 ...
0
votes
1answer
68 views

Benefit of DGPS for relative accuracy and speed measurements for receivers close-by each other

Consider that we are interested only in the speed and relative position accuracy of GPS receivers (i.e. their absolute try position on earth is NOT important). These receivers are all in a 90m x 90m ...
2
votes
1answer
77 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 ...
1
vote
0answers
101 views

Available modules/products for GPS+IMU sensors shipped with sensor fusion SW?

Are there any solutions/products (modules) in the market that integrate GPS and IMU sensors that come together with the sensor fusion algorithms (Kalman filtering etc.) implemented and ready for use? ...
2
votes
2answers
285 views

How can I transfer waypoints and tracks from Base Camp into QGIS2.6?

I'm working on transferring all my field data from Garmin Base Camp onto QGIS. This is an attempt to overcome the learning curve from basic trail GPS mapping programs to the real thing. I'd like to ...
9
votes
2answers
193 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? ...
0
votes
1answer
141 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 ...
2
votes
1answer
394 views

How to interpolate GPS data correctly?

I'm working on a project that involves using linear interpolation to fit lines to lat/lng points. I'm pretty new at scientific programming related stuff, and I was wondering if people could steer me ...
4
votes
3answers
559 views

Wildlife surveys using tablet and GPS, import/export to/from ArcMap

I've found some info about this on a previous post (Advanced android app for mapping and GPS logging), but it didn't provide enough info, I'm hoping some other tech experts can help! I have a tablet ...
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
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 ...
20
votes
6answers
4k 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 ...
0
votes
0answers
14 views

Simple app for generating polygons - offline solution [duplicate]

As the title says, but capable of importing raster, and exporting the vector to a compatible format to QGIS. The vector-layer needs attribtutes as well and has to be GPS-orientated. IOS or Android. ...
1
vote
1answer
43 views

Use of satellite-based augmentation outside of base station coverage

In certain locations GPS units can recieve an SBAS correction signal (WAAS, EGNOS etc) but are outside the coverage area of a base station. For example, EGNOS signals can theoretically be recieved in ...
2
votes
0answers
74 views

About Timestamp in Geotagging

I'm on my reasearch for GPS and sensors integration. I've just wondered that to integrate between GPS and camera you need time offset synchronize which called as a timestamp. But how does software ...
0
votes
0answers
71 views

How to average GPS tracks?

I have GPS data - point cloud in a shapefile. Now I want to average this data and get on output a single GPS track. Here I found images but can't find algorithm. Maybe gdal or postgis can do it? Any ...
2
votes
0answers
47 views

How do I accurately measure a gps track over a long distance?

I am measuring the length of the Continental Divide Trail that goes from the Mexican border to the Canadian border. I have a .gpx file of the entire route in NAD83 with tracks about every 50 meters. ...
5
votes
3answers
174 views

Mapping Trails with GPS - Hardware Suggestions

I have been hired to map about 100km of XC ski trails. I am super proficient in GIS but have not done any detailed GPS work since college when I worked with some sort of Trimble explorers. This is a ...
34
votes
12answers
26k views

Tablet or smart phone GPS vs “real” GPS

I've been reading a lot today about android and iphone devices being used for spatial data collection in the field and it sure seems to be that single purpose devices such as the extremely popular ...
2
votes
0answers
67 views

Create “mean” line from multiple lines using QGIS

I have multiple lines features (also have them in multipoints...) representing similar path (mountain trails, in this case) with various GPS precision, resulting in many lines close to each other, but ...
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 ...
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 ...
0
votes
1answer
36 views

Where can I find documentation on the NMEA sentences supported by the Garmin GLO?

I just picked up a Garmin GLO Bluetooth GPS device. Does anyone know where I can find documentation of the NMEA sentences it outputs?
2
votes
1answer
444 views

How is Precise Point Positioning (PPP) exactly done?

I am looking for a positioning accuracy that is higher than normal consumer-grade GNSS receiver (mostly GPS/GLONASS hybrids with +- 5m precision). I came across RTK with dual receiver setup (base ...
0
votes
0answers
397 views

Base station for RTK-GPS using RTKLib

First of all I would like to say that I am new to gis-se and as such I will try to comply as much as I can to your policy. That said I am actually doing a little project which as the title says ...
8
votes
0answers
306 views

Is there open source GPS post-processing software? [duplicate]

Possible Duplicate: Post Processing GPS Data with open source software Here at the office we have a couple of 15-year-old Trimble 4700 and 4800 units but now we don't have the software to ...
3
votes
0answers
260 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 ...
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
0
votes
0answers
42 views

postgis st_makeline, points with rounded time

I have seen a number of example SQL statements that take gps points, order them by time, them use ST_MakeLine to make a Linestring. I think my trouble comes from that fact that my times are rounded to ...
2
votes
1answer
78 views

Coordinate display in Terrasync

I'm using Terrasync on a Trimble GeoXH 6000 - set for WGS 84 and UTM. It acquires satellites fine, but instead of displaying my current location in UTMS, the skyplot screen shows "12RVU" and then a ...
2
votes
1answer
190 views

Convert Garmin or iPhone weird GPS Coordinates

I am trying to find a way to convert over 500 locations I have saved in my Garmin iPhone GPS app (iPhone 4S using Garmin StreetPilot v2.7), but I can't find a way to convert these coordinates as they ...
3
votes
2answers
468 views

Import Trimble Data without Pathfinder

I don't have Pathfinder on my computer. I need to pull data off of my Trimble unit (Geoexplorer 6000 series) and save it on an external hard drive or USB key, without using Pathfinder. This way, I can ...
2
votes
1answer
104 views

Map Matching GPS to Road Network [duplicate]

I'm working on a project for which I have GPS points and I would like to extract the sequence of roads related to those points. I know that this is called "map-matching" and that there is a load of ...
0
votes
0answers
99 views

Drawing Line on existant Shapefile in Geotools

I have a shapefile that is opened and looks as such: Now I am attempting to draw a line from two points I click on that map; however the code they give for the QuickStart.java example is ...
1
vote
1answer
45 views

Categorizing GPS data based on cumulative time using ArcGIS Desktop?

I have GPS data which includes “Lon”, “Lat”, and cumulative Time from 0 (sec) as fields. I want to add an integer variable new field, “Trip,” which starts from zero, and is incremented by one after ...
1
vote
0answers
31 views

ArcPad GPS Data Captured misaligned

Data captured using ArcPad 10 is not displaying properly. The .shp file created in arcpad is diplaying a NAD 83 Zone 17 projection. From what I've been reading, the datum for GPS is usually in WGS ...
2
votes
1answer
238 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 ...
1
vote
0answers
201 views

Calculating distance in m in xyz between GPS coordinates that are close together

I have a set of GPS Coordinates and I want to find the speed required for a UAV to travel between them. Doing this by calculating distance in x y z and then dividing by time to travel - m/s. I know ...
2
votes
1answer
82 views

Mobile device GPS into a PDF Form

This is an issue I've been trying to solve for a while and am told it's not possible. I have made a PDF form with an input box for coordinates. As the form is for use on mobile devices, I would ...
0
votes
0answers
76 views

Calculating angle of telemetry GPS points in ArcGIS for Desktop?

Does anyone know if it is possible to calculate the angle of telemetry GPS points in ArcMap? I would like to calculate the angle made when the bird travels from one GPS point to the next. Picture one ...
3
votes
2answers
137 views

QGIS Installation on Windows

I'm newbie to QGIS and to this forum. I want to develop application using Qt on QGIS to real time updation/mapping of a symbol using GPS co-ordinates. Initially i have installed QGIS on Windows 32 ...
2
votes
0answers
34 views

Reference and Beacon Stations in Vietnam

I'm not sure if this question can be asked in this forum, but here it goes. I am on my way to conduct some remote sensing research in Vietnam, which includes logging of coordinates. This should ...
3
votes
1answer
146 views

Address and coordinates of European cities request

I have a database of couple of millions of records which I would like to geocode. The data consists of addresses and council. All addresses are of a certain European city. Questions: May I have ...
0
votes
1answer
186 views

Add GPS tracks directly to a PostGIS table

Disclaimer: I am a total GIS newb and I have a use case I have not seen elsewhere. Background: I drive country roads looking for old building, cemeteries, school houses, etc and I record the ...
1
vote
0answers
56 views

Calculating new satellite position given pseudorange measurements

I'm looking for a reference/text for an explicit formula to calculate a satellite position given pseudorange measurements from later epoch times. I've seen a lot of matlab code on the internet but I ...
1
vote
2answers
194 views

Does India Have a CORS (Continuously Operating Reference Stations) Network?

Does India have a CORS (Continuously Operating Reference Stations) network? If yes, can anybody provide more details about it?
2
votes
3answers
665 views

What format is this GPS tracking string?

I am receiving tracking data from a device and I am not sure what is the format/standard of this string in order to properly process the variables, this is a sample string received: ...
1
vote
0answers
51 views

GPS with QGIS--what happened to the capture point?

I have been using QGIS for years but when v. 2 came out and important functionality seems to no longer work. In 1.8 the "capture point" or "capture line" buttons on the GPS panel would work. Ever ...