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

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3
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1answer
49 views

Is there a method to tell which hemisphere a point belongs to, in WGS84 geoid, where the equator is an arbitrary ellipsis?

I use the WGS84 geoid (because I'm working with a GPS chip). I define an ellipsis that splits the surface in two parts, lets name these 'A' and 'B'. This ellipsis is defined by two points 'a' and ...
0
votes
0answers
27 views

How to get correct measure with PostGIS SQL query? [duplicate]

First of all, sorry my bad english. I am new at gis. So I want to measure my road. I want to use measure unit kilometers. But I am a bit confused. I have a garmin etrex gps device. So I get my ...
2
votes
2answers
162 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 ...
0
votes
0answers
16 views

Yandex Navigator / Maps - Determining user location

Kindly redirect me to a more appropriate forum in case there exists one. I am an active user of Yandex.Navigator App (available for all kind of mobile platforms). Whenever I open the App, even though ...
1
vote
2answers
45 views

Where can I find the coordinate system used by GPS

How do you determine which geographic coordinate system is used by a GPS device? For example, my Garmin GLO is outputting NMEA data with lat/lon. What system is represented by those lat/lon values? I ...
3
votes
1answer
44 views

How does GPS Unit make sure that they have the same time reference from GPS Satelites?

I've been reading readers about GPS to find how GPS work, but one thing still bothers me. To calculate distance from gps unit/receiver to gps satellite, it uses the difference between radio signal ...
0
votes
1answer
62 views

Getting GPS coordinates perpendicular and parallel to AB

I already posted this question here And I got the solution thanks to Fang but the problem is that the coordinates I need to use are GPS coordinates and apparently GPS needs a different formula than ...
0
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2answers
31 views

Deployment of Zeno Field 3.11 in windows 8.1

Is it possible to install Zeno Field 3.11 in windows 8.1?
2
votes
4answers
135 views

Where to license non-automotive POIs for France, Spain and Portugal?

qualified POIs are needed for a commercial project - should cover broad out-of-car usecases (not needed: parking, gas stations). Could be commercially licensable data or derived from national geodata ...
5
votes
1answer
388 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
59 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
462 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
35 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
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 ...
1
vote
0answers
72 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
123 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
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? ...
0
votes
1answer
32 views

What does 'Course Made Good' in NMEA string mean?

I was looking at some GPS data that a client sent me. It has lines like this: $GPRMC,183123,A,1725.4170,N,07825.4779,E,37.80,297,161214,, I was looking at http://aprs.gids.nl/nmea/#rmc, which says ...
0
votes
1answer
102 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
367 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 ...
0
votes
0answers
78 views

Store GPS trace with timestamps, then interpolate location by time

I'd like to: Load a 1-second interval GPS trace (not GPX) into PostGIS Then query the table at sub-second accuracy (about 5Hz), and get PostGIS to interpolate the location by time. Is this ...
4
votes
3answers
534 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 ...
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 ...
0
votes
0answers
13 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
37 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
49 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
47 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
34 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
161 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 ...
1
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0answers
34 views

QGIS GPS Information Menu Automatically Add Points

We are using a Surface Pro 3 with Windows 8.1 64bit, Bluetooth GPS, and QGIS (2.4 standalone download). We have opened a new QGIS project and are able to connect to the GPS unit within the GPS ...
33
votes
12answers
24k 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
54 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 ...
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 ...
0
votes
1answer
23 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?
5
votes
1answer
14k views

How to make work tablet integrated GNSS (GPS) on Windows 8 with QGIS?

I have tablet - Dell latitude 10, running Windows 8, with integrated Broadcom GNSS Receiver BCM47511 (GPS,Glonass...). Because it is integrated GPS and Windows 8, there is the "new" way of providing ...
2
votes
1answer
219 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
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0answers
208 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
226 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
6k 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
28 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
51 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
116 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
203 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
42 views

Map Matching GPS to Road Network

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
83 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
39 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 ...