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

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139 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 ...
2
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1answer
285 views

Will external antenna on handheld GPS improve location in a forest?

I want to improve the probable accuracy of waypoints that I collect during vegetation surveys on foot, where the canopy is overhead and continuous. My handheld receiver unit is a Garmin GPS 60 ...
2
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1answer
63 views

Can I capture shared vertices with a Trimble GPS?

I'm trying to figure out how to use Trimble GeoXT and GeoXH GPS receivers to efficiently capture small farm fields in rural areas. The main issue that I'm struggling with now is trying to deal with ...
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0answers
122 views

Deriving length values from GPX files in QGIS

I’m missing something real obvious and I apologize for revisiting a topic addressed in several Q&A’s here. I’m an experienced GIS user (not programmer) who’s new to QGIS (can’t afford Arc in ...
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2answers
211 views

Is newer better? - should I replace my 2008 model Garmin GPS60 handheld GPS?

I use my mid-price Garmin GPS60 handheld GPS device to record waypoints for vegetation surveys and other field surveys, often under tree cover. In asking 'should I replace my old unit', I should say ...
2
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0answers
48 views

Trimble pathfinder data dictionary default value exclusion

Is it possible to have a numeric attribute in trimble pathfinder without having to use a default value? I am trying to make a numeric attribute compulsory to fill in BUT because the data dictionary ...
0
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1answer
421 views

Trying to convert GPS LatLng Android coordinates to use in ArcGIS rest - esriMeters

I am getting the LAT and LNG position from Android. Both values are of type double, in Degrees. For example: NY, USA Latitude: 40.7142700 Longitude: -74.0059700 Then I have a service ArcGIS REST. It ...
2
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1answer
157 views

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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2answers
688 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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0answers
27 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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1answer
78 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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1answer
104 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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0answers
55 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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1answer
45 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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1answer
147 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 ...
2
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2answers
187 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 ...
2
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0answers
102 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 ...
0
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1answer
187 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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3answers
3k 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 ...
2
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1answer
504 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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2answers
467 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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0answers
104 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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1answer
103 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 ...
0
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0answers
36 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 ...
3
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1answer
240 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 ...
0
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2answers
187 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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1answer
152 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 ...
2
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2answers
1k 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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0answers
47 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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2answers
2k 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 ...
2
votes
1answer
347 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 ...
2
votes
4answers
99 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 ...
2
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2answers
109 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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0answers
92 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 ...
2
votes
1answer
417 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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0answers
33 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 ...
3
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0answers
126 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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0answers
307 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 ...
3
votes
2answers
435 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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1answer
167 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 ...
1
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1answer
431 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, ...
0
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2answers
472 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 ...
2
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2answers
486 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?
2
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1answer
130 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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0answers
63 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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2answers
294 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 ...
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0answers
21 views

KML To Automobile GPS

I've created a bunch of Placemarks and have them in a kml file. Is there a way to get this into the GPS of a car?
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0answers
323 views

Updating OSM map from within PhoneGap/Cordova App

I am trying to build a sat-nav application that allows the users to dynamically update the map that their application is using. So if the user updates the map with a new road then that road is ...
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0answers
30 views

Differential Correction Wizard Doesn't Pop Up?

Any Trimble GPS Pathfinder Office users out there ever run into this problem? When I try to run the differential correction wizard the program stutters for a brief second then nothing happens. All ...
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0answers
54 views

Data Collection Solutions

I am seeking a new data collection software for a team of biologists who track migrating animals from planes through aerial telemetry. I currently use Delorme TOPO USA but when collecting point data ...