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

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What is “gps on demand time injection”

Android defineds a GPS device capability I couldn't find reference to It's defined as GPS_CAPABILITY_ON_DEMAND_TIME in gps.h The description in the comment explains: GPS on demand time injection. ...
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38 views

Map-matching GPS points to the road network!

I am quite a newbie in Postgres and Postgis so please be simple and clear :) I am trying to do a simple map-matching (or path-inference if you wish) of some GPS points. I am using postgres(postgis). ...
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26 views

Convert WGS 84 cartesian 3D coordinates(x,y,z) to geographic coordinate (lat/long) [duplicate]

Do you know where can I find the formula and data needed to effectuate this conversion? Sorry I don't give enough information. I get the description file of a CORS ...
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13 views

How to visualize GPS dataset fro MysQL database and select dense areas

I am using Geolife dataset for simulation. I followed the pre-processing data tutorial to store all .plt files in a mysql database and export it in a .csv file. However, I want to select the ...
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20 views

QGIS GPS not editing offline database

I have a set of layers from PostGIS that I have converted to offline. I am attempting to edit them via GPS. If the layer is point data, then I can add in that data without issue. However when I go to ...
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29 views

PostGIS and Mobile Devices Maps

I'm still learning the world of GIS reading this Introduction to PostGIS. So far I understand things but since I have an idea that I plan to later work on, I found something that I didn't quiet grasp. ...
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15 views

Free trajectory data mining tools

I am doing a mapping of systems/tools used for different trajectory data mining tasks (e.g. trajectory classification, pattern mining and outlier detection). The tools i am looking for should be ...
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34 views

How many calculations are needed?

I am working currently on a small e-learning project at the university for a professor. Now I am not an expert or anything in this field, I just learnd what I know online from the various sources and ...
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27 views

Transfer from Android phone to Windows OS truncates lat long

I am clicking GPS enabled pictures of sites which are less than 500 metres apart through Android based Samsung ACE Duos phone. I later use Google Earth on my Laptop to view these geo tagged pictures. ...
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28 views

Conversion of (lat, lon, height) from GPS to another CRS

I have latitudes, longitudes and ellipsoidal heights derived from GPS readings, referenced to the ITRF08 system with vertical datum (CGVD2013) - http://webapp.geod.nrcan.gc.ca/geod/hmod/hmod.php How ...
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12 views

Replicating CSRS PPP solution in RTKPOST, gLAB

I analyzed the GNSS position data using CSRS , RTKPOST, gLAB. From the results, I noticed that the CSRS results for NEU errors is the least, while RTKPOST and gLAB were comparatively larger. I tried ...
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72 views

GIS Equipment for 911 Call Center [closed]

I am the GIS administrator for a 911 call center. Currently we use ArcGIS for our mapping, and my director recently told me that I have a budget every year to purchase GIS/GPS equipment or training. I ...
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13 views

Is there a way to create a custom, navigable GPS route?

Is there some sort of way to create a custom GPS route that can say, be plugged into a maps app like Google or Apple maps? For instance let's say I created a route that is a drive along Pacific ...
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14 views

Processing obs files in glab (PPP)

I have data for a trimble receiver and would like to run PPP analysis for its positioning errors. I use glab for this purpose. For the orbit and clock source, I use the final orbit data provided by ...
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16 views

Given raw NMEA data, how do you estimate accuracy on-the-fly?

I have streaming NMEA data from a GPS device to my application. One of the sentences includes HDOP. I previously calculated the circular error probable (CEP) for this unit. How can I calculate the ...
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8 views

Inputs for GNSS data processing : NEU error

I have some .?o and .?n files that i need to process to obtain the NEU errors. I understand that for a very accurate estimate, i need reference stations (the more, the better) to obtain baselines. ...
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10 views

Remote USb gps device location in QGIS server

I have QGIS server in linux. I have navika usb GPS device connected to a laptop.Laptop and QGIS server are interconnected via ethernet.How do i get the GPS device location in the server as the devicis ...
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27 views

Getting Intra-Maps roam to interface with internal GPS

I've got Intramaps Roam installed on a Panasonic Toughpad fz-g1 with integrated u-blox M8 gps. When I open up GPSviewer I can see my position, everything seems fine. When I enable GPS with ...
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240 views

What causes the GPS offset/shift in China?

I've spent close to two full days trying to understand the nature of the infamous GPS shift in China. After sifting through the noise, two recurring symptoms are that: GPS coordinates (WGS-84) plot ...
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1answer
72 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, ...
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133 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 ...
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28 views

Why does my Android always show same lat/long for geotagged photos? Can I override this?

I am looking to collect point data with my Samsung Galaxy S3 using Android 4.1.2 However, every photo returns the exact same lat/long position Is it possible to override this and if so, how?
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27 views

For GPS point data using android, default camera app or other software?

I'm curious to know about your experience using the default android camera app for geotagging photos vs other apps. I am going to trial a few different of these apps over the next month or so on ...
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31 views

ODK Collect GPS Accuracy

Good day. Is it possible to require a minimum accuracy of the GPS widget? I know about accuracy threshold but what I need is to prevent forward swiping/finalization of the form if GPS accuracy is low. ...
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27 views

how do calculate nearest point in earth map with coords

I am having trouble calculating nearest point for another point with earth coordinates. I am particularly interested in calculating the intersection of linestring vector with earth coordinates. I'm ...
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17 views

Movement along a path with inaccurate location updates

Given a path and a vehicle traveling along that path. At intervals (~1 sec) the location and speed of the vehicle along that path is provided. The location of the vehicle is not accurate, a noise ...
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32 views

Getting started with RTK base stations

My employers are looking into a partnership with a company that provides RTK base stations (they specialize in Topcon equipment) and are planning to replace our old total station with a Topcon HiPer ...
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52 views

iPad with real GPS

Historically, iPads have not had true GPS. The GPS they have goes through a cell phone network, called Assisted GPS. Now I hear that iPads are coming with true GPS. How do I know if a particular iPad ...
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25 views

Map Positioning and Routing on Android

I have been instructed to create an small offline application in Android that have to: a) Use our own map in JPEG format as the basemap (Google Map / OpenStreet Map is not applicable) b) Show the ...
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80 views

How to extract NMEA outputs from an external bluetooth GPS to an Android device

I am requested to create an Android app that have to connect to an external Bluetooth GPS and read the NMEA output and visualize the location on ad digital map. I am a new comer in this aspect. ...
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24 views

Regarding processing of GNSS data heights

I have a TRIMBLE GPS receiver and in its data, I am able to derive the ECEF xyz coordinates. My objective is to obtain the orthometric heights, which I could do using the equation h = H + N. My ...
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79 views

How to import GPS waypoint, track info into ArcMap 10.2?

I heard that ArcMap 10.2 can import waypoint and track information directly from a GPS without bridging it from MapSource or BaseCamp software. Can someone give me tutorial or link to a video that I ...
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57 views

How to decode GPS coordinates from Android device XML file?

I’d like to decode the location coordinates from the XML file from my Android phone (SGS2). Any solution how to do it, how to convert them to usable coordinates (longitude/latitude)? Looks like it's ...
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50 views

How do some companies receive GPS data from vehicles if GPS's can't send any data?

I know that some companies offer tracking services for vehicles such as live GPS tracking they can access any time, but as you can't use the GPS protocol to send any data i wonder how the do it... I ...
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47 views

Is this distribution of GPS positions caused by multipath distortion?

I have some GPS points that are close to where they should be, but not nearly close enough (horizontal precision is around 10 meters). Looking at the positions which comprise these points (there are ...
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19 views

road network construction using latitude longitude and timestamp

I have gps data(latitude,longitude and timestamp) of a city over a month I want to use some routing algorithms on that data so need to construct road network or graph So how to construct road network ...
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1answer
71 views

How to change ODK GPS accuracy threshold?

I am using ODK with ONA in XLSForm. As the GPS accuracy default is 5 meters, it automatically accepts it when it reaches 5 meter. Is it possible to change the default accuracy to less than 5 meters ...
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13 views

M-field to a point layer calibration (Linear Reference)

I am working with routes with ArcGis 10.1 and I'm trying to calibrate the routes using a points layer imported from text file obtained from a GPS. But the points layer doesn't have m-field to be ...
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23 views

Generating Random Location (newLat,NewLon) given current position lat,lon)

I have been trying to implement a method described on this site to generate a random location given my current position. It is described here: How to generate random locations nearby my location?. ...
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37 views

How to measure RTK accuracy of a moving vehicle?

I am currently working with tractors using a RTK enhanced automated steering system. One of the biggest problems is that even RTK can have a inaccuracy of 2cm. This can be too much for some possible ...
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63 views

Getting OpenLayers degrees rotation to point right way?

I am working on a fairly simply proof of concept for a tutorial to blog. At the moment it is simply to show how a SatNAV type functionality could be achieved in a browser - However I cannot for the ...
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49 views

GLONASS speed and altitude limitations

I'm looking for some info about the possible limitations for the GLONASS navigation system, something similar to the GPS COCOM limits. Is there any limitation on speed AND/OR altitude for this ...
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115 views

Does GPS correct for continental drift?

Does GPS correct for continental drift, and if so, how? (I'm mainly interested from the perspective of consumer devices such as smartphones.)
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50 views

Analyzing long lat location data to find locations in proximity

I am looking for a tool to analyze location data (long lat values from vehicle GPS available). The goal is to identify locations which are in close proximity (within a circle of 30-60ft) and then ...
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41 views

How to parse EXIF GPS information to lat,lng decimal numbers

"EXIF_GPSAltitude": "(220.279)", "EXIF_GPSLatitude": "(55) (40.711) (0)", "EXIF_GPSLatitudeRef": "N", "EXIF_GPSLongitude": "(8) (30.2282) (0)", How should i understand above example as degree, min, ...
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124 views

Read position from windows tablet GPS

I have a Lenovo Miix 2 tablet and I am developing a project with a Java servlet. I want to read GPS data in my project. Can I read this data using Java? and/or HTML5? update: In this project, I can't ...
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90 views

How can I find GPS coordinates of the geographic center of US counties?

How can I find a list of the GPS coordinates of the geographic center of each US county?
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39 views

Calculating a point Lat/Lon from another Lat/Lon point angle

I need help for a solution of this problem to make an algorithm: : I have a point O center of a circle of radius r, on this circle there is two point P1 and P2. I know latitude and longitude of ...
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32 views

How do I compute uncertainties in the positions transformed using Helmert transformation?

I am familiar with Python, MATLAB and Mathematica. My data is given by Cartesian coordinates (positions in X,Y,Z (meters), standard deviations XX, YY, ZZ (meters) and a correlation matrix (XY, YZ, ...
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80 views

Mapping raw GPS data to Openstreetmap's Node/Way/Relation

So, I have a bunch of raw GPS data points which constitute trips. I want to add semantic information to those data points. For example I'd like to be able to say that a trip consisted of taking street ...