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

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26 views

How to crop orthophoto using GDAL

I have orthophoto(GeoTiff) and 4 GPS coordinates that represent rectangle. How can I crop orthophoto by using GDAL? (I need to remove areas outside of rectangle) UPDATE: I tried gdal_translate ...
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7 views

How to extract GPS data from video stream

I just got a Garmin Virb Elite video recorder and recorded some videos with it, and also confirmed that Garmins own player can show the GPS information on a Map. This video recorder stores GPS data ...
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11 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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9 views

find the format of GPS string in c#

I am developing a AVL system using c#,My avl doesn't have any datasheet or guide,so from my gps i get this data every 20 second string aaaa2 = "24-42-10-10-03-31-05-16-03-15-07-16-35-45-...
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16 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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1answer
36 views

Establishing DGPS Connection With Old Equipment?

I am trying to do a differential surveying project with some outdated equipment, specifically: -An old AllegroCX personal handheld computer (Win 4.1) with SurvCE loaded on it to collect data and ...
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13 views

How to make multipart polygon shapefile in DNRGPS

How do you save multipart polygons from DNR GPS? I have read the short blurb under "roll up tracks" at this link, but either it is not clear, or I am misinterpreting it. When I follow these ...
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23 views

How to use ST_ClosestPoint [duplicate]

I am new using a GIS software. I have to study the performance of some GPS receivers by computing its positioning error. To compute the error I need a "reference" set of positions to be compared ...
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1answer
32 views

What will post-process differentially correct raw Bad-Elf Surveyor U-Blox NMEA/raw UBX?

I have a Bad-Elf Surveyor unit which claims accuracy ~1m when post-processed, but I am at a loss to find software that can differentially correct the raw NMEA/UBX logs that the unit will record. I ...
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1answer
36 views

Sticking GPS waypoints to closest road?

I am new with QGIS. I want to study the performance of different GPS receivers, and to do so I need to compute the error made by each one. The problem is that I don't have any reference to be ...
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1answer
21 views

Tracks in a GPS file format

How to fill a file with different GPS tracks so that when opened in a GPS track viewer the tracks appear simultaneuosly as different tracks? What GPS viewers do that?
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300 views

Odd, old coordinate formatting from 1997 GPS

A typical coordinate is given as 68 35 067 N 123 54 817 W. I thought maybe some old timers could help me out. The author says in his report of the time that they were using a GPS, but I contacted ...
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1answer
27 views

Using multiple satellite constellations (e.g. GLONASS, GALILEO) by GPS unit?

I am trying to do research on GNSS/GPS units available and it seems like there is a large price jump for units with more satellite constellations (maybe I am erroneously making this correlation) that ...
2
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1answer
37 views

Data Transfer not working, Files to Pathfinder another way?

Typically I would use the Data Transfer Utility to retrieve files from my Trimble Geo7x and run them through GPS Pathfinder to create usable shapefiles. Currently I cannot get the transfer utility to ...
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4answers
62 views

Transfering topographic map from ArcMap onto Garmin GPS?

I have a Garmin 64S GPS unit that I'd like to get a topographic basemap layer onto, so I'm not wandering with a blank screen while getting to my field sites for my research. I'm using ArcMap 10.3.1, ...
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0answers
27 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 ...
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19 views

Using QGIS like ArcPad to average coordinates from GPS reading for point feature?

I have been able to sync my SXBlue GPS receiver to my tablet with QGIS via the GPS Information Window / bluetooth. I can view our coordinates, PDOP, etc and want to create a point shapefile that ...
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1answer
36 views

Sunlight based on GPS coordinates and UTC+date

I'm trying to create a sunlight map. I found the following question: Sunlight layer into CartoDB However, my interest is in trying to calculate the amount of sunlight manually. Can you please point ...
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1answer
54 views

Is Coarse / Acquisition PRN pseudo random code value hardcoded into GPS receiver?

From what I read there are 37 ( 1-32 are for traditional GPS code 33-37 are reserved for other use and ground transmitting ) carefully chosen pseudo random sequences 1023 bits long called Coarse/...
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1answer
70 views

develop own mobile app connecting with external gps receiver

I want to develop a mobile app that can use external GPS as source for collecting high accurate point. And I just found how to connect Trimble R1 or Trimble R2 to android device using bluetooth based ...
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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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1answer
45 views

How close can a commonly used GPS device come within actual location of target

With resepct to meters/feet how close will a GPS device get me, say if device (like iPad), is "common". Say, could I upload a particular coordinate that has two-tree houses in my back yard and discern ...
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0answers
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 ...
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2answers
41 views

preparing GPS coordinates for processing in gis

I'm currently working on a masters in archaeology, using QGIS to examine some palaeolithic sites. I created a database with the site coordinates, which I collected from looking at bibliographies of ...
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1answer
51 views

How can I stream attitude (roll,pitch,yaw) into Google Earth?

I am streaming position data (lat, lon) of an airplane into Google Earth via NMEA 0183 ($GPRMC, $GPGGA sentences) and it works OK (I generate and stream these from my own software). Now I would also ...
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3answers
58 views

Is there a correlation between the absolute errors of nearby GPS receivers?

Suppose I have two different GPS receivers located x meters apart and their exact location is know. Then, would there be a correlation between the absolute errors of nearby GPS receivers? By absolute ...
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1answer
47 views

How do I file a QGIS bug report through alternative means?

I have tried to file a bug report per the instructions on the QGIS get involved page. Signed up for an osgeo account, but keep on getting kicked off. It could be my connection (Wireless DSL, wildly ...
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0answers
21 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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1answer
29 views

Attribute table Does Not Show Any Lat Long Field in ArcGIS for Desktop?

I had import shapefiles data which is a point features from GPS receiver. The points are well on pointed on the ArcGIS display, but when I open each attributes table, there is no field show the ...
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27 views

Looking for a web service to return landcover/landuse data based on Long/Lat

I am looking for an web based API to get location data based on Latitude and Longitude that will return landcover/landuse feature data for a mobile app. It will preferably return the data in a json ...
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3answers
60 views

QGIS 2.12/14 Add GPS Point missing geography?

I am trying to use the integrated GPS module from QGIS to add data points to a shapefile while in the field. I managed to get the connection between qgis and the gps working and my location is shown ...
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35 views

Working out meter accuracy based on number of visible GPS satellites?

I am working with NMEA data and I curious whether there it is possible to calculate the accuracy, in metres, based on the number of visible satellites or whether there is an alternative way? The two ...
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1answer
14 views

Issue with a Leica RX1200

Just got handed a Leica RX1200 unit (which I'm not familiar with). When I turn it on it opens up the window/select program screen and almost immediately switches to a perpetual hourglass icon. We'...
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25 views

How does distanceTo use accuracy in android.location.Location

I would like to know how exactly accuracy will be used in getting to know the distance with the build in function distanceTo(Location location). I have read everything in https://developer.android.com/...
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1answer
90 views

Satellites needed to receive proper 1pps signal

So I have read that you need 4 satellites to be able to get a proper position from your GPS. But how many do you need if you are only interested in the 1pps signal from them? And what effects play a ...
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8 views

What is the standard method of finding satellite positions in between the 15 minute intervals in an SP3 file?

SP3 files provide satellite positions for every 15 minutes. How would you find the satellite position at a time between two logged positions, i.e. 7 minutes after the last logged position? I can ...
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3answers
149 views

How to evaluate performance of GPS/GNSS unit

I need to integrate some sort of satellite-based positioning for a mobile robot project. I am at the very beginning - I got 2 u-blox GNSS evaluation boards (these NEO-M8Ts) - I chose an integrated ...
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1answer
53 views

Calculating length (in meters) of GPS track? ArcGIS 10.3.1

I'm trying to calculate the length of a GPS track in ArcGIS 10.3.1. What I've done so far is: Converted track using the "Points to Line" tool Opened attribute table Made new "Length" column Opened "...
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2answers
33 views

Proper handling in PostgreSQL/PostGIS only after many queries?

I am trying to analyze GPS data of a parade on a fixed route with a certain variance due to the urban surrounding (canyoning). I'd like to project the GPS waypoints to the nearest points on the route ...
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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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0answers
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 ...
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29 views

writeOGR R and add an icon symbol [closed]

I am wondering if there is a way to add an icon symbol to the R code I am using to export data in GPX format. In the navigation program I import the GPX file into all of the of coordinates are ...
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1answer
31 views

What is the difference $GPRMC and $GPRMCA?

What is the difference between $GPRMC and $GPRMCA strings? I can find online documentation about $GPRMC strings, however I have a device that sends $GPRMCA strings. $GPRMC,225446,A,4916.45,N,12311....
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2answers
100 views

Quantitative vs Qualitative heatmap

I'm having a debate with a colleague of mine over whether generated heat maps are quantitative or qualitative in nature. The underlying data source is GPS points. The GPS devices that we use are ...
2
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0answers
11k views

Key difference between NAVIC Indian Regional Navigation Satellite System (IRNSS) and American Global Positioning System (GPS)? [closed]

What's the key difference between NAVIC The Indian Regional Navigation Satellite System (IRNSS) and American GPS system? Radio Frequency Accuracy guaranteed Modulation Area Covered Engineering ...
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0answers
33 views

Open layers 3, map.on('moveend',..): Differentiate between user interaction and map.setCenter() calling

I am implementing OL for a GIS application and want to add a 20 seconds timeout when the user scrolled the map, after which the GPS auto track function should resume. For that I am utilizing the map....
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0answers
42 views

Trimble Access vs. TerraFlex: Which is simpler for creating data entry forms? [closed]

I am working on an archaeological project and need to create forms for users in the field to use and take photos. I am renting a Trimble GNSS unit and can get Trimble Access for free with the unit, or ...
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1answer
44 views

What are some automated techniques for cleaning bad data from a GPS track log?

I have been having some problems with "bad trackpoints" in the track logs I've been creating, especially in bad signal conditions. In some cases these obviously jump miles away from the true location;...
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48 views

Panasonic toughbook FZ-G1 gps troubleshooting

Not long ago, I purchased the "optional" GPS module for my FZ-G1 toughbook hoping that it would be an easy install. It may be that the GPS module came defective or there are more subtle steps to the ...
2
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1answer
34 views

How can I match Geolife traces using TrackMatching or similar tools?

I am working on route prediction and I decide to use realistic trace of moving object, I have choose geolife dataset it is composed of 278 users and every user has its trips presented in GPS or GPX I ...