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

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49 views

Determine when heading off course

How does google or other map providers with routing capabilities determine when you are not staying at the right course? I am trying to figure out how to implement this feature in my gps that I am ...
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0answers
225 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 ...
2
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1answer
64 views

Topology Editing using ArcView (now called Basic) license level of ArcGIS Desktop?

I am building a geodatabase from data collected on a GPS handheld in the field. The GPS device collects decently accurate information but I need to make sure all the polygons, lines, and points are ...
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0answers
252 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 ...
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0answers
159 views

Anyone know an iOS data collection app that exports raw GNSS data for differential correction?

I am pretty sure the answer to this is "No", but throwing this question out there in case someone knows of something I haven't stumbled across yet. I am seeing less expensive GNSS units show up on ...
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1answer
163 views

How do I force gpspipe to read from a USB Serial device rather than a server address with a port and everything

I'm desperately trying to grab the simplest piece of information I can out of my usb dongle from the command line. A program of mine needs to use it so it has to be a STDIN/STDOUT type solution. I ...
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1answer
109 views

How to compare GPS absolute positioning receiver accuracy

I have two different types of GPS modules which are in absolute positioning mode (pseudorange data) Lets say one of them is attached in microcontroller (such as arduino, rasbpy, etc) and the other ...
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0answers
57 views

QGIS linked to camera for GPS based triggering?

Has anybody done this yet? I'm new to QGIS and have just started exploring. I'd like to integrate flight lines and camera triggering if anybody can direct me to the right forum or area. Thanks!
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2answers
878 views

Does iOS know the phone's location solely from cell tower, i.e. without GPS data?

Question Does the iOS operating system know the phone's location even if one could turn off the iPhone's built-in GPS module or if it was broken? Elaboration What I understand I understand that ...
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1answer
42 views

I want to trace a gps device

I want to create a device that should transmit its location to a server using anyother medium other than GSM. Bascially I need a tracking device which i could give to my worker and he goes to a forest ...
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1answer
60 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 ...
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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 ...
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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 ...
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2answers
166 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 ...
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1answer
127 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 ...
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2answers
46 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
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4answers
137 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 ...
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1answer
436 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
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1answer
89 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 ...
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2answers
542 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
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1answer
89 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
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1answer
79 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 ...
2
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2answers
579 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 ...
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2answers
199 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
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1answer
191 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
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1answer
429 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 ...
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3answers
585 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 ...
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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) ...
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6answers
5k 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 ...
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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. ...
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1answer
47 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 ...
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0answers
93 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 ...
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0answers
105 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 ...
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0answers
70 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. ...
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3answers
192 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 ...
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12answers
27k 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
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0answers
86 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 ...
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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 ...
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1answer
59 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
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1answer
746 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 ...
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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 ...
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0answers
300 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 ...
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4answers
8k 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
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53 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
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1answer
102 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
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1answer
313 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 ...
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2answers
825 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
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1answer
167 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 ...
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1answer
48 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 ...
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0answers
36 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 ...