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

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53 views

Understanding Latitude Jumps

I'm decoding some AIS messages and outputting KML files showing routes. Looking at some ships in the Adriatic Sea there are some weird Latitude jumps that I don't understand. Several ships show ...
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1answer
211 views

Is it better to take the elevation of a GPS unit or that of a Digital Elevation Model?

When searching of gps routes in wikiloc, for the trailrunning race "Transvulcania" I have several routes to look. I downloaded a lot, but every route has a distance between 71 kilometers and 74 ...
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1answer
140 views

GPS data -tracking analyst

i have GPS data from 15 trucks for one month. The data include (location x-y, speed, altitude and vehicle_id). I have used tracking analyst to visualize the data but i need to group them by day to ...
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44 views

Is it possible to find Lat,Long coordinates of points within a polygon whose GPS coordinates is known [duplicate]

I have a set of gps coordinates which make up a polygon. Is it possible to find Latitude,Longitude coordinates of points within this polygon using GPS coordinates of the polygon I already possess. ...
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135 views

suggest me some good online coordinates converter for GPS NMEA data!

I want to check my GPS conversions from NMEA format to decimal degrees and vice versa. Can anyone suggest to me some online GPS converters for quick reference where I will get entire conversions by ...
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1answer
759 views

How to convert negative NMEA latitude and longitude values ('S' and 'W')?

I'm getting from GPS data in the form of NMEA. There I'm getting positive latitude and longitude values('N' and 'E'). How do I convert the negative latitude and longitude values('S' and 'W') into ...
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88 views

Using GPS to field walk through a LiDAR scene

I am doing field surveying for archaeology using Lidar. If I attached a USB GPS to my laptop would it be possible to track where I am "in real time" on the Lidar as I am field walking? I'm wanting to ...
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168 views

Length of a long distance GPS track

I have a list of GPS points logged by a vehicle and I'd like to find out the length of the logged route. The problem is that the vehicle logs only every 10 minutes, so I don't have too many points to ...
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1answer
207 views

Creating custom maps for Garmin Oregon 600

I have a Garmin Oregon 600 GPS receiver and a map I made in QGIS. Where can I find a step-by-step guide to getting this map onto my GPS unit? A static JPEG or PNG map is fine since I'm not interested ...
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1answer
438 views

GPS tracking data string format for GRTQ device

I get GPS data from tcp (php socket), but for some devices (GRTQ) I will get an unreadable string. First devices sends: *HQ,XXXXXX,41,4#V1,time,A,**Lat**,N/S,**Lng**,W/E,000.00,000,date,FFFFFBFF,432,...
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49 views

analysis of GPS measurements

I would like to design something like a filter to reject the GPS measurements with low precision. I know that calculating the distance and acceleration by the given velocity and coordinates might be ...
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58 views

Historical Traffic Condition + Vehicle Path Advise Required

I'm currently working on a project which involves tracing the path(GPS coordinates) taken by a vehicle (1) and measuring the traffic conditions(is it jammed and whats the speed during the time the ...
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62 views

Finding gps projection of 3d photo?

I have an aerial photo from Paris and I would like to plot gps paths and 3d surfaces on top of it (using R, python, etc). . The problem I have is converting my gps coordinates to 2d coordinates on ...
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1answer
296 views

Calculating speed along point feature class (.gpx) in ArcMap?

I have imported a .gpx file into ArcMap as a point feature class. Each feature has a Point z as well as a DateTime. I want to create a graph that shows speed as a function of distance. How do I do ...
2
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1answer
223 views

Trouble Converting from a shp. to gpx file and up loading to GPS

Currently I have a series of random points within a shapefile that I would like to upload to my GPS. Every time I try to upload the points via "Save file" it come up with an error message (posted ...
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1answer
147 views

Has anyone been able to install a GPS device 'Explorist Magellan 210' (Old, may be 2005) on windows 8?

Windows is unable to reckognize my device. It's 10 years old but fully functionnal. I would at least make it work as an external disk. All suggestions are welcome.
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209 views

Windows desktop application that allows to visualize, edit, download, upload and convert GPX files?

I am looking for a simple application that will allow me to visualize GPX data, edit and create new GPX tracks, areas and points and download/upload GPX data to and from devices. This application ...
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0answers
287 views

Good GPS navigation app for iPhone with downloadable OFFLINE maps?

I am looking for a good GPS navigation app for my iPhone that will work away from wifi and cell coverage (GPS only) and thus allow me to download offline maps. Paid app is OK. Must Have features: ...
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1answer
582 views

GNSS planning online vs trimble planning 2.9 software

Why using the same parameters GNSS planning on-line and Planning 2.9 Trimble show me different Dilution of precision (DOP on the graph)?! Which program is better mission planning solution for GNSS ...
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2answers
208 views

Measure my Cats movements , Accuracy of Mobile phone GPS at metre scale . how to improve it

I wanted to get some information related to an idea I have I have a lot of cats and a big garden. The cats generally roam through the garden and this location is fixed and Known If i have known ...
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3answers
314 views

What is a good, small GPS data logger that stores accuracy information? [closed]

I'm looking for a small GPS data logger for geotagging photos, and I've had trouble finding one that meets my requirements: Small, key-fob size would be ideal. It should also store its tracks on on-...
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1answer
84 views

GPX-Tracks are not displayed correctly by many applications/web applications

I have a problem regarding GPX tracks that were created from Shapefiles using QGIS. The shapefiles were created by selecting all parts of a route from a PostGIS database. The polylines were merged ...
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1answer
437 views

Accuracy of GPS and HDOP

Given a handheld GPS with an accuracy of roughly 2 meters (verified through field tests) and an observation with an HDOP of 1.2, the accuracy of that one observation should be within 2 meters X 1.2 of ...
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35 views

Discrepancy between importing same data from CSV and GPS [closed]

I have been importing similar data by using two different methods: Entering the coordinates manually in excel and save as CSV, then importing in QGIS through delimited text layer. Column A is name, ...
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1answer
1k views

import GPGGA data to google earth

I have collected some GPGGA data in *.GPS file. Now how to import these GPGGA into Google Earth Pro.I want to see the result(lat, longt and height) in map. The file is opened like that: $GPGGA,023302....
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3answers
237 views

Is there a service to check whether a gps path belongs to a public road?

I have a bunch of GPS tracks. I want to exclude the ones which go via public roads. I'm interested in off-road segments only. Is there any public api to check if a given set of coordinates belongs to ...
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2answers
152 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
323 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 (...
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1answer
69 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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141 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
276 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 ...
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49 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 ...
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1answer
461 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 ...
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1answer
207 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
857 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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29 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 station(http://geodesy.noaa.gov/...
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1answer
85 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
137 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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57 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
46 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
158 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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2answers
199 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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119 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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1answer
201 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 intra-...
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3answers
4k 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
573 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
533 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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107 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
108 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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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 ...