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

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Garmin etrex 10 and QGIS

I want to know if anyone has been able to download data from a etrex 10/20/30 directly from Qgis. The usb protocol decsribe in a recent post does not do the trick. GpsBabel documentation states that ...
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1answer
374 views

Differentially correct GPX file

Is there any way to differentially correct a GPX file using free or open-source tools? Does a GPX file contain the necessary information for differential correction (I can put the timestamp in it ...
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1answer
72 views

How does a GPS unit ensure it has the same time reference as a GPS satellite?

I've been reading about GPS to find how it works, but one thing still bothers me. To calculate distance from GPS unit/receiver to GPS satellite, it uses the difference between radio signal sending ...
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181 views

Mapping Trails with GPS - Hardware Suggestions

I have been hired to map about 100km of XC ski trails. I am super proficient in GIS but have not done any detailed GPS work since college when I worked with some sort of Trimble explorers. This is a ...
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2answers
4k views

postprocessing GPS coordinates with RINEX data to improve precision?

Im doing some mapping for OSM in my region and I am curious if the precision of tracks from a GPS Receiver can be improved if they are post processed with RINEX data. The tracking is done with a ...
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1answer
300 views

Finding Lost Samsung S4 with Lat/Long Coordinates

I lost my Verizon provider Samsung S4 phone while running on a narrow trail surrounded by brush. The phone no longer has power. Using Google Location History I obtained that Latitude and Longitude ...
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4answers
901 views

Does the strength of GPS weaken in rural areas?

Does the strength of GPS weaken in rural areas? For example, based on how the satellites work, would the strength in the centre of Australia differ from a populated city in Europe?
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3answers
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What is the easiest way to measure a polyline using either QGIS or ArcGIS

I've collected a bunch of GPS polylines (WGS84). What is the easiest way to measure the length of these lines in KM?
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291 views

Differentiating a building from a road on a map?

This question was originally asked here by Steven and I felt the question was better asked here. Steven would also like to know the sources Google buys it maps from. I remember seeing a post about it ...
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2answers
417 views

Tracking a vehicle without GPS device

We are planning to write an application which have to track the user driving in his truck in the cities like New York city accurate upto which lane he was driving on. In the cities with those tall ...
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5answers
389 views

How do I find software for my GPS?

I recently unearthed a GPS unit I purchased a few years. It's a Garmin GPSmap 60 (picture) and has a usb port on it. Is there a way that I can link it to my mac? I do have windows installed also, and ...
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3answers
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Mobile, Offline viewer for geographic data

Currently, field crews consumer geographic data via laptop (no internet, no gps). ArcReader. I would like to get them shapefiles (or some derivative of a shapefile) on a mobile platform (smartphone) ...
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1answer
190 views

Extract one GPS fix per day from data?

I am in the fortunate position of having 2 years worth of animal movement data. With such a large amount of data I would like to extract only one fix per day to make it easier to work with. Data = 14 ...
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Connecting GPS to ArcGIS via USB

Is there a way to connect a GPS to ArcGIS via USB? At the moment the GPS extension only appears to support comm port connections. It would be good to know if a USB connection can be made, then perhaps ...
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4answers
1k views

Matching GPS tracks

I'm looking for a proper way to process multiple GPS tracks (so time ordered list of lat/lon points) and match/classify that segments, that are covered by multiple tracks: So it's not about ...
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3answers
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GPS post processing - Differential Correction

I have a large set of collected GPS points that I'm pulling into Arcgis from SQL and creating an xy event layer to then map them. The fields for the points are as follows: recorded, lat, long, ...
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3answers
82 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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3answers
569 views

Wildlife surveys using tablet and GPS, import/export to/from ArcMap

I've found some info about this on a previous post (Advanced android app for mapping and GPS logging), but it didn't provide enough info, I'm hoping some other tech experts can help! I have a tablet ...
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3answers
451 views

API to suggest nearby streets

For an app I'm developing, I want to use the phone's GPS to locate it. I then want it to list streets that are nearby. The customer might be in his back garden for example, and this may be closer to ...
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2answers
672 views

Does iOS know the phone's location solely from cell tower, i.e. without GPS data?

Question Does the iOS operating system know the phone's location even if one could turn off the iPhone's built-in GPS module or if it was broken? Elaboration What I understand I understand that ...
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1answer
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Distance calculation : Integrating incremental gps data

I am trying to build a GPS based odometer based on android. Currently , I am calculating incremental distance changes very frequently ( < 5 meter movement). The distance calculation in android is ...
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1answer
5k views

How to calculate Bearing between two GPS points

The following returns 150 degrees using C# converted from JavaScript Bearing formulas, but Google earth returns 210 degrees for the same values. The broken code is GetBearing() but I've also included ...
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1answer
368 views

RINEX specs and OS library

Is there any OS library to read/write/process RINEX data? I've been wanting to start a OS library to read and write RINEX, which is something I need for a project, but not actually post-process them. ...
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2answers
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Point interpolation in route

I have a set of GPS coords with X,Y and Course. I need to interpolate additional points based on the course of each point. It would be a simple line intersection based on lines drawn using the 2 ...
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2answers
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Trimble GeoXH, XM, XT - Data logging without Terrasync or GPSCorrect?

Is it possible to capture data for post processing on a Trimble GeoXH, XT, or XM without using Terrasync or GPScorrect? Specifically I would like to create a RINEX file. A Trimble 4000 series receiver ...
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1answer
2k views

What is a .ssf file?

What exactly is a .ssf file? I am refering to the .ssf files used with Trimble GPS units. I am aware that it is some sort of post processing correction file, but I do not know more than that.
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1answer
276 views

Proper work flow to move manholes and pipes to surveyed location

I would like to know how to accomplish the following task using QGIS. I have an existing point shapefile representing sanitary sewer manholes and an existing polyline shapefile representing sanitary ...
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3answers
196 views

How can I add 3 axis orientation information to my photos?

I have a survey project where I need to record not only the location, but the direction (bearing and angle of elevation/depression) that the camera was pointing at the time the picture was taken. ...
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1answer
341 views

Calculating “travelled distance” of a GPS track without including “stops”

I have a set of GPS tracks from a cycling event and I want to correlate their distance along the route. Problem is: when a rider stops, generally by entering a covered place, GPS keeps logging (low ...
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1answer
415 views

GPS tracking and Web mapping?

We are developing a tracking software and we are the stage where we test the reliability of our location stigma on the following web-maps Google Map Nokia HERE Open Street Map (OSM) We observe ...
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1answer
211 views

GPS Elephant Tracking II: Is ArcGIS basemap imagery orthorectified?

-- For my original question and pictures of elephants wearing GPS equipped anklets, go here. -- I'm experimenting with the use of GPS anklets to track the movement of zoo elephants. This has proved ...
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1answer
708 views

How to show a geoTiff on an iOS application?

I'm developing an iOS application that will use offline maps. These maps are on GeoTiff format but I don't know how to do it. I've found this question: How to display a GeoTIFF on mapView but it uses ...
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111 views

What projection system is used in China which is aligned with WGS84 [closed]

I have some GPS tracks in Beijing. I want to project it and convert the lat long degree values in meters for calculation in euclidian space. I was wondering what is the most suitable coordinate and ...
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GPS tracking using smartphones [closed]

We're looking to launch a study that examines spatial behaviour on a university campus. Given the near ubiquity of smartphones among our study population, we're excited about the possibility of using ...
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0answers
252 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 ...
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0answers
767 views

Microsoft Surface vs. iPad for mapping

I was recently introduced to the Avenza PDF app for iPad and I've been using it in the company I work for to help our field crews find their way around, and record waypoints and tracks. The app takes ...
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3answers
7k views

Distance between GPS coordinates

Given a database of GPS points, a center GPS location, and a radius R (in meters), how can I find all points in the database that are within a distance of R of the center point? Will the distance ...
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6answers
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Garmin GPS 78 Interface

Does anyone know how to interface a Garmin GPS 78 Marine GPS with their computer to manage waypoints (upload, download, save, etc.) Previously I was using the MN DNR Garmin tool, but it no longer ...
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6answers
988 views

Advantages of a GPS enabled PDA for field asset management

I'm having some trouble trying to convince some people of the advantages of having a entry level GPS enabled PDA for asset management. I've been asked to look into GPS enabled cameras, I've since ...
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1answer
157 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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4answers
429 views

Why is GPS almost unavailable without a data connection?

When travelling to foreign countries, ie. when a data connection is unavailable because I don't want to spend big bucks using a roaming data connection, I noticed that GPS is virtually never ...
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4answers
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Can *.ssf files from Trimble GPS be imported as features to display in ArcMap?

I have not come across *.ssf files before but I believe they are a Trimble GPS binary format. Someone has asked me if these files which he thinks have line/poly features can be imported for display ...
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2answers
138 views

QGIS Installation on Windows

I'm newbie to QGIS and to this forum. I want to develop application using Qt on QGIS to real time updation/mapping of a symbol using GPS co-ordinates. Initially i have installed QGIS on Windows 32 ...
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4answers
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How to clean/edit GPX (tracks) files recorded from GPS device?

During a long trip, I have recorded tracks of my journey with the GPS of my smartphone. I have ended up with about 30 GPX datafiles. Now that I am back, I am trying to draw a map of this trip. I ...
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6answers
9k views

Sending GPS Location to server

Is it possible to send my current location on iPhone or Android to the server so that others can view my current location?
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348 views

GPS capable rangefinders or cameras that can capture lat / long data from a distance?

Anyone have experience using this technology? i.e. field verifications of structures where you need to capture the lat / long of a house that is 1000 feet from the road with limited access.
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1answer
67 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 ...
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1answer
257 views

Project point to map with Arcpy using GPS Coordinates

I am trying to create a new layer with just a single point using arcpy. All that is provided is a gps lat and long. It seems like it should be a simple problem but I just can't get it to work. I've ...
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3answers
140 views

Is it necessary to use a third party service for serving this case?

I have been assigned a task to help build a mobile app, which only shows terrain view of map with a fixed (min/max) zoom level based on mobile phone position and moveable markers which are provided ...
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2answers
309 views

Several questions about using spatial data?

If you have spatial data for SQL server, can you use the spatial data (both geometry and geography) in another application for instance ESRI ArcGIS? Is spatial data a standard that every GIS ...