GPS is a space-based satellite navigation system that provides location and time information.

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Sources of realtime spatial data

I'm trying to set up a demo that serves up live spatial data, but am having trouble finding any suitable example data sources. Ideally I'm looking for something that updates every few seconds; either ...
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8answers
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Why does GPS positioning require four satellites?

I have a question on the GPS positioning algorithm. In all books I've read for 3D positioning we need four satellites, and I don't understand why. We need to calculate three variables: x, y, z. We ...
10
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2answers
472 views

What Type of GIS Powers Automobile Navigation Systems

My sister-in-law was inquiring about where she can buy updated DVD's to load into her car's system. Obviously I know the dealer/OEM would love to rip her off for such data, and I knew of no ...
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12answers
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Location-based game using GPS

I am not sure if this forum is proper place for that kind of question but i hope to get some advice... I looking for some scenario (examples, ideas) for urban game (location-based game) with usage of ...
3
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1answer
298 views

What is the DNSC08 Mean sea surface model ellipsoid based on?

Does anyone know what Danish Space centre DNSC08 mean sea surface model uses as the reference ellipsoid? there is no meta data on the web site: ...
0
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1answer
978 views

how to convert the easting and northing to a point and saved in a feature class in ArcMap?

I write a program to decode the message from the GPS device to get the easting and northing , but I don't know how to convert the easting and northing to a point and saved in a feature class in ...
2
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2answers
834 views

GPS - Garmin 60CSX connectivity issue

I have a Garmin 60csx, about 2 years old and I have attempted to connect it to my laptop/ArcView (GPS toolbar) using the Detect GPS Port to no avail. There is no port number being displayed and that ...
2
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0answers
401 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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1answer
129 views

Finding intermediate points and speed over a segment

I have a dataset which is in the form of ( Time , Car ID, Speed at that moment, Lat,Long) and I need to do some machine learning on the data to answer the following questions : Best route from ...
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2answers
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How do I download tracks from the GARMIN GPSMAP 78 usin DNRGarmin?

I have been able to download waypoints to DNRGarmin by accessing the GPX file. However, I have only been able to view waypoints. How can I download tracks?
2
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1answer
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How to read multiple .gpx files in R [closed]

Suppose I have a number of .gpx files (these contain GPX waypoint data from a Garmin eTrex). I want to load them into R with different names and manipulate them. I can read one file thus: ...
9
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4answers
593 views

Does GPS signal quality depend on the chip manufacturer? Does it depend on weather?

(Sorry if GIS is not the right place to post this question to). Recently me and my school friends had a GPS software application project to pursue at the university. A device very similar to this ...
4
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1answer
275 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. ...
4
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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 ...
3
votes
6answers
2k views

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 ...
4
votes
2answers
2k views

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 ...
3
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1answer
1k views

File IMG from OSM

Is it possible to convert or open an IMG file from OSM? I don't find a solution for the visualization and conversion. Thanks
6
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2answers
1k views

Trimble GeoXH vs GeoXT and GPS Correct

I am about to purchase a new GPS unit. I currently have a GeoXT and have used the combo of GPS Correct/ArcPad with GPS Analyst/ArcMap to correct the collected data to submeter (or close to it). ...
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1answer
219 views

delorme gps and delorme X map alternatives

We have a group doing field work and are having issues using delorme gps and delorme X Map and Delorme X Map. Wondering if there is a way to connect the delorme GPS pn 40 to ArcReader / ArcExplorer in ...
13
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3answers
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Post Processing GPS Data with open source software

I am using Magellan Professional Mapper CX working on ArcPad 7.1 platform. It has sub-meter accuracy after post processing. Without post processing the data collected in the field is off by 10 to 15 ...
2
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2answers
1k views

Locations of Geodetic Survey Benchmarks

Does anyone know where I can find a list of geodetic benchmark locations for Ontario? (If a list even exists that is...) Thanks
3
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1answer
494 views

Can an htm file be imported into Trimble's Data Dictionary Editor?

We've received several data dictionary files from other entities and they all are in *.htm format. We were hoping to not reinvent the wheel, as these are massive data dictionaries, so does anyone know ...
7
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3answers
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Do's and Don'ts for GPS Localization

We have recently purchased some new GPS survey gear (ProMark 500) and we have set up a localization around the town using some of the known survey marks. While I'm pretty confident that I have got it ...
16
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3answers
529 views

Lightsquared GPS controversy: Where is the analysis?

GPS World reports that Lightsquared's network of 40,000 transmitters will interfere with GPS signals. Initial technical analyses have shown that the distant, low-powered GPS signals would ...
22
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6answers
806 views

How to cope with the newly discovered GPS bug? [closed]

Today the New York Times broke the news that after the Clinton Administration turned off Selective Availability in the GPS system, a bug had been introduced into the GPS satellite software itself, ...
5
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1answer
346 views

PLT track in PostGIS

What are the best practices for importing and aggregating tracks (in my case in 'plt' format) in a PostGIS table, grouped by user. Are there any tools/db models/tutorials available?
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3answers
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Calculate maximum speed from GPS data

I have raw GPS locations for a track, and need to get maximum speed. Simple methods (calculate speed between 2 points, take max) will give meaningless large numbers due to GPS inaccuracy, the point is ...
26
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5answers
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Does an earthquake affect GPS?

There are news reports saying that the Sendai earthquake a couple days ago has shifted the earth on its axis and moved the island 8 feet. Last year, there were similar reports with the earthquake in ...
5
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3answers
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Free MobileGIS like ArcPAD

I'm looking for open-source program like ArcPAD. I have read all questions and answers, but i find nothing. I need the program for PDA (Dell axim x51v + GPS modul) and I want mapping points (trees or ...
14
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8answers
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Mobile Data collection options

What COTS software is available to do mobile data collection, with GPS positioning. Map display not required. I'm looking across the board (platform wise). I'm already aware of... RhinoSpect ...
5
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2answers
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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 ...
9
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10answers
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Need a Benchmark GPS Trajectory data-set? Anyone?

I'm looking for a benchmark GPS data set, available for research purposes for free. I've found GeoLife GPS Trajectories dataset from Microsoft Research but I find it a little incomplete. What I need ...
12
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4answers
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Clustering Trajectories (GPS data of (x,y) points) and Mining the data

I've got 2 questions on analyzing a GPS dataset. 1) Extracting trajectories I have a huge database of recorded GPS coordinates of the form (latitude, longitude, date-time). According to date-time ...
6
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4answers
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How can I get my GPS track data into a graphics program?

I'm using a Garmin Edge 705 bike GPS/computer unit, which produces .gpx files. I can use the standard software it comes with to plot on Google Maps etc, but I'd like to be able to output just a vector ...
26
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7answers
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Why don't they use cell towers like GPS satellites?

If my understanding is correct, a GPS satellite produces a pretty simple signal which is basically composed of its location and its time. Given 4 of these signals, then one can uniquely solve for the ...
4
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3answers
284 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 ...
12
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3answers
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GPS Tracking by SMS

I have a GPS Tracker which sends the GPRMC string of the NMEA 0183 protocol, at fixed periodicity, to a predefined number as SMS. I am looking for a software which can port these incoming SMS to a COM ...
17
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6answers
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How correct is the “Accuracy” value given by GPS devices?

I have a Garmin Forerunner 305 and a Google Nexus One Android phone. From the GPS on both these devices I can get a "Accuracy" value that is usually between 6-20 meters. How much can I trust this ...
4
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5answers
361 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 ...
11
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4answers
746 views

GPS to map workflow, for non-GIS folk

What applications and workflow(s) do you use for gathering, displaying and storing GPS data, with your centralised corporate data, for people who are not GIS folk? We're in the process of ...
8
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1answer
126 views

Is there a geodetic benchmark that is fixed with respect to plate tectonics?

I see that NGS benchmarks are used to monitor the movement of geologic plates. Is one of the benchmarks assumed to be in a fixed location, with movements of all other benchmarks measured with respect ...
3
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1answer
225 views

How can a single line be computed from multiple possibilities

I have datasets containing continuous GPS streams of data that represent routes or trails. For any given route, I probably have at least 5 (in some cases many more) different sets of data. Given that ...
4
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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?
12
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3answers
368 views

Software for analyzing GPS tracklogs to extract human-readable placenames

I have a pile of GPX-formatted tracklogs for many countries where I've travelled over the years (the GPS-device has been continuously on and recording for most of the trips). I would now like to ...
6
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2answers
571 views

Managing error with GPS routes (theoretical framework?)

I'm looking for the appropriate theoretical framework or speciality to help me deal with understanding how to deal with the errors that the GPS system has - especially when dealing with routes. ...
3
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1answer
1k views

show position on google map/earth, from gps data, using google API

For those that have used google's API for mapping (google maps/earth), I would like to know if is it possible to develop an application to receive NMEA data from a gps receiver, extract position, and ...
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1answer
244 views

Converting GPS heights to AHD heights

I was wondering if there is a way to convert heights that are logged from a normal bluetooth GPS to AHD heights.
3
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6answers
855 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 ...
0
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3answers
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Length of forms in ArcPad10

I'm trying to create a survey with about 250 questions in ArcPad 10. Normally you would expect that a form you created in any application will be able to scroll in PDA if it is too long. But the ...
3
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2answers
639 views

in seach of gps tracking (web) service to use with rails web app

hey out there GISers, i am looking for a gps tracking service i can hook gps devices into and request their infos via a ruby on rails webapp. does anybody know some? any help is appreciated! thanks, ...