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

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5
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339 views

GPS data based track/trip calculation algorithm available?

Currently I'm receiving position data of moving assets every 90 or 120 seconds (depending on the asset). What I'd like to achieve now is to detect standstill and movement phases (tracks/trips) on the ...
3
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48 views

Uploading Shapefiles to Garmin?

I am trying to upload shapefile polygons onto my Garmin 60Cx GPS. I use the Trace tool and load shapefiles via Minnesota DNR's application. There are almost always gaps in the shapefile on the GPS, ...
3
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192 views

Import GPS SINEX (for velocity analysis) into Sarscape or processing with others software

I try to import GPS snx. into Sarscape 5.2 (use GPS Import tool) and getting error 115) ) gps_type : [sinex] 116) ) generate_kml : [OK] 117) ) generate_shape : [OK] 118) ) ...
3
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3k views

Translating hdop, pdop and vdop to metric accuracy from given NMEA strings

How can I translate dilution of precision to a metric unit? For example: say I got 1.2 in hdop from NMEA sentence of my GPS receiver, in what should I multiply to get a metric accuracy? Just like the ...
3
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219 views

How to determine and send alert SMS for next bus stop in a GPS tracking system?

In my gps tracking system (PHP/MySql) I have got 5 Stops for a vehicle. Whenever the bus reaches stop 1, the passengers at stop 2 should get an SMS alert. And in the same way for the sops followed by....
3
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64 views

what criteria should I consider in buying a pocket GPS

It's my first time making this kind of choices, and I really don't know how to go with a choice or another. I basically know that it should have good durability , a good battery life and good ...
3
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182 views

Ways to measure similarities/congruence of tracks (point features) in ArcGIS

I have a sets of GPS coordinates recorded while tracking different cross country runners. What I would like to do is to compare how similar the tracks of the individual runners are. Is there a test ...
3
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151 views

How can a GPS receiver know the estimated error?

I would like to plot a circle of possible error on the map in a GPS app. From http://en.wikipedia.org/wiki/Dilution_of_precision_(GPS), we can see that GDOP is equal to "delta of output location" ...
3
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416 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 ...
3
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421 views

Are there any shapefile-based GPS data recorders?

I am looking for a data recorder that can be programmed to send a serial data request to a field computer and then accept and record an incoming data string and tie it to GPS location and then save ...
3
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548 views

How to read a .GPB file in C#?

I have a .GPB file, I need to extract the common GPS data from it but I don't find a clear structure that specify the contents of that file. as a sample record from file 00000260 02 11 A9 61 E7 96 ...
2
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28 views

Improving Trimble GPS Pathfinder Office and TerraSync coordinate systems workflow?

We have GPS survey projects all over the country (CONUS and OCONUS) and I am wondering what the best practice is for having to deal with multiple coordinate systems. I can go from WGS84 UTM 18N meters ...
2
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36 views

How to count near intersecting polylines and merge them?

I have a dataset with several polylines created by GPS points of car trips. I am trying to create a simple heatmap where roads with more traffic (where polylines intersect) get darker. I already ...
2
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0answers
89 views

how to transfer GPS device coordinates into mobile android app?

i'm trying to make an android app that collects data field in high accuracy, since the phone native GNSS doesn't provide highly accurate coordinates, i want to use Coordinates provided by a real GNSS ...
2
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0answers
52 views

Can I read ephemeris data from GPS receiver?

I want to filter the GPS data. when I use the low cost GPS receiver, it gives erroneous data. therefore I want to apply some filtering technique. How can I read ephemeris data from GPS receiver? I ...
2
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37 views

Why time differs between gps and ntp exactly 90 seconds

EDIT: This question can be closed due to figured out the problem was in the NTP configuration. While the gps device is no gps data received, gps device is send gps time to server as zeros ("...
2
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0answers
82 views

High-level method for offline future road elevation data

I am new to GIS, so please do not hesitate to call me out in providing limited information. I have a .tiff Terrain (elevation) data file for the east coast of the US and a .osm.pbf OSM file for ...
2
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0answers
38 views

Capturing GPS coords in EXIF header for JPEGs with ArcPad ImageBox control?

Problem with capturing GPS locations in EXIF header for JPEG photo using Esri's ArcPad and its ImageBox control. I have customized forms for ArcPad. I have added three ImageBox controls to a form ...
2
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0answers
48 views

Are there methods of filtering gps-data with metadata?

In our project we captured GPS-tracks from a few electric vehicles in the timeframe of a year. In total we captured around 13000000 GPS-points this way. The captured data comes from electric powered ...
2
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0answers
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 ...
2
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0answers
289 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: ...
2
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50 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 ...
2
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0answers
122 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 ...
2
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0answers
774 views

Can I put a button that automatically inputs GPS coordinates into a google form? (or other spreadsheet populator)

I am currently creating a Google Form and part of the questionnaire requires the user's current GPS location. Is it possible for a button to be able to do this and automatically populate the field? Or ...
2
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173 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 ...
2
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144 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. I'...
2
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167 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 ...
2
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68 views

Reference and Beacon Stations in Vietnam

I'm not sure if this question can be asked in this forum, but here it goes. I am on my way to conduct some remote sensing research in Vietnam, which includes logging of coordinates. This should ...
2
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0answers
118 views

How can I store height info from GPS in QGIS?

I want to use QGIS as a tool for collecting GPS-Data in the field. One use case would be simple surevy tasks where I want to store the three dimensional position of points. QGIS is working fine on the ...
2
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0answers
257 views

Is it possible to display labels in background files (.imp) on Trimble GPS units?

I have been trying to figure out if this is possible for a while now. I know if you load a file in as a data file, you can click on a feature and the label will pop up. However, you cannot view a data ...
2
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0answers
174 views

Looking for a good solution to have GPS position on KMZ files on Android platform

I'm looking for the best solution / app on the android platform to show my GPS position over a KMZ file, possibly offline. Here is what I've tried to do: Google Earth Android app I downloaded KMLZ ...
2
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198 views

best free easy GPS software? (not necessarily 'real' GIS)

Our search and rescue group is looking for some advice on what free and user-friendly (no computer savvy required) software folks could use to interact with their own GPS. Doesn't have to be a 'real' ...
2
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99 views

Calculate Moving Time

I am wondering how web apps like Garmin connect or Strava calculate a "moving time" from a gps track. For example I might record a GPS track on my Garmin GPS that has an elapsed time of 5:34:26 but ...
2
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0answers
474 views

GLONASS Satellite Position Prediction using Almanac Data

GLONASS ICD has a section named "Algorithm of calculation of satellite motion parameters using almanac". It gives the formulas in order to calculate the position and velocity of the satellite. ...
2
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0answers
248 views

how to make decent sense from scattered river depth measurements

I sampled river depth at scattered positions and I want to be able to make a map and GIS layers out of it. My problems are: As the river meanders the interpolation I do in scientific packages i,e. ...
2
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0answers
296 views

Should 2D Positions and 3D Positions be considered conceptually different entities?

Let's suppose we want to model GeographicPositions, described by coordinates or coordinate tuples inside some Coordinate Reference System. Also, these would be put inside some sequence to represent ...
2
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467 views

calculating bounding box from known centre coordinate and zoom

I have a map, the centre of that map (centrepoint) is = -37,175 ( gps) I know the zoom of the map = 13 I know the size = 320x320px I know there is 111111m in a degree of latitude and a varying degree ...
2
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0answers
233 views

Interpolate current Course value of GPS using previous Course values

I have a set of GPS data with Lat, lon and Course. I need to interpolate current value of course, using previous values of Course. The formula I am using is not accurate in curves.In C language I was ...
2
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177 views

QGIS on android4 with bluetooth GPS

I'm trying to set up a moving map on my tablet (asus, Android 4). I've installed QGIS (latest version), which works. I've got a blue tooth external GPS, which I've paired to the tablet. However, I ...
2
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0answers
183 views

From gpx to line segment 1Km using ArcGIS 10

I have gpx files containg points with attribute data such as time and date. I'd like to convert them into lines, and that is not a problem, but what I want to do is create 1Km segments with time and ...
2
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0answers
286 views

How would I modify GPS tracker to accept two nmea inputs and gpsmarker to include a heading vector?

I use QGIS on a research vessel and wonder whether I could modify the QGIS 1.8.0 gpsinformation widget. I want to achieve two things. 1. Change the GPS marker to a boat shape which points in the ...
2
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0answers
195 views

How to enable OSM map in Garmin?

I've installed two OSM maps, but I cannot use them in Garmin. See the window of Utilities / Manage Map Products: The maps are not lockable, but I cannot use them in Garmin... What shall I do to be ...
2
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0answers
150 views

How to configure various client applications to display AVL data?

Given x number of GPS units transmitting NMEA formatted strings back to a server (xxx.xxx.xxx.xxx:xxxxx) is there a way to listen in on the traffic and parse NMEA formatted strings for display on a ...
1
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0answers
13 views

East, north, up (ENU) velocities (m/yr) to long, lat and h; GPS

Have the velocities (east, north, up) data in m/yr. How can I convert this into lat, long and height (formula and etc) velocity mode (m/yr) 0.000036 0.001330 0.013553 offset at at first epoch (m)...
1
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0answers
12 views

QGIS Plugin -> QgsVertexMarker points missing: Anyway to find out which points are not visible?

I am trying to plot live feed of three GPSs running at 10 hz using my own QGIS plugin. I was using QgsRubberband initially which worked fine. I recently added QgsVertexMarker to plot every data points ...
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0answers
17 views

GPS data can't be read when the device is moved

I am getting data from avl system as you can see with this format : *HQ,4106016320,V1,090458,A,5257.4318,N,15840.4221,E,000.00,000,101115,FFFFFBFF,250,01,0,0,5# As you can see the data that I get ...
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0answers
29 views

Problem in layer overlapping (qgis)

I want to plot gps pts on qgis (version 2.14.1). I have added the vector layer of SE Asian countries, and added the delimited text layer of my gps pts which included species name, lat and lon. ...
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0answers
22 views

Will GPS L2 make RTK more reliable?

I currently experiment with an affordable L1 GPS RTK system based on u-blox NEO-M8T with RTKLIB and higher quality patch antenna (with ground plane). I wonder what is the role of L2 signal in an RTK ...
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0answers
21 views

how to show gps laltitude/longitude in input in android application (webview)

i devellop an android application with , jiquery mobile 1.9, cordova 2.4 ....., i want to display the coordonnate of gps (lot,lat) in input like in the pictures,i'm tired with this code but it cant ...
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14 views

Adding sequential codes to GPS waypoints

When using a GPS (a Garmin GPSmap 62 -- but our team has other similar equipment), when I want to add a new waypoint, the system displays a default number for it (e.g. 202). If I add the 202, the next ...