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

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103 views

Taxi fleet simulation - MATSim a useful tool?

I am working on a university project and I would really appreciate some advice: My project consists in modeling the taxi fleet of a major city and investigating if replacing a percentage of the fleet ...
4
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1answer
116 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. ...
2
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1answer
160 views

What is relation- difference and/or similarities between PPP, SBAS, GNSS, RKT?

Recently i came across lot of terms such as IGS, GNSS, GPS,PPP, WAAS, EGNOS, GLONASS, CORS and many more ... I know some of them I can group them such as GPS, GLONASS, GALILEO . And then there is SBAS ...
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1answer
56 views

USGS Earthquake GPS Metadata: Buffer Zones & Python

I'm making a python web crawler that gets USGS earthquake GPS data, and I'm wondering how I should process the latitude longitude pairs to see if it falls within a specified radius of a specified GPS ...
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1answer
100 views

Converting unknown type of coordinates to lat/lon

Our company is using Total Station (Surveying Machine using SOP) to calculate GPS coordinates and its results are something like this Easting: 3250193.00, Northing: 1115573.00, Elevation: 656.00 ...
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27 views

What is the format of this Tracker String?

I've got a client, who has plenty of Chinese trackers and he wants to use them in our vehicle tracking portal. He has no idea of the company or the structure of Tracker String. I have little idea ...
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1answer
70 views

Hand-written coordinates from a Garmin NUVI

I've been asked to map point data that was collected in the field by manually writing down the coordinate from a Garmin NUVI 1490 LMT. They were put into a spreadsheet and sent my way which I was ...
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29 views

Garmin conversion track

I have problem when import garmin GPS tracks with software for Android. I found this code: public static int importTracks(String path, Context context) throws ClassNotFoundException, IOException { ...
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0answers
79 views

How do I export sensor records from a Trimble GeoExplorer to a mapping program?

So I am fairly new with the GIS world and could use a lot of help!! I am currently surveying with a Trimble Geoexplorer 6000 XH What sort of mapping program can I use to export sensor records to ...
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3answers
1k views

What GPS device do I need for vehicle tracking?

I am a programmer with no connection to Geographic information, except that I work on application which uses google maps. So here is my problem. I need some device, which I will be able to set in a ...
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0answers
40 views

Link GPS Data Logger to a website

Is there a way of linking GPS data logger to a self made website for tracking purposes? I want to create a tracking website which uses the data from GPS logger and connect to Google maps to show the ...
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0answers
65 views

Convert GPS to cartesian and scale to a bounding box

I've little knowledge about geographic systems and i'm gonna try to explain my problem the best i can. I've gps coordinates captured from a mobile device WGS84 store in a file, each file stores a ...
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1answer
158 views

Calculation to convert db data to Lat/Lng degrees

In a database I have the following Lat/Lng data. I wish to convert it to a readable format. 177514245:34726053 => S 32 7.3947, E 115 51.4245 177513828:34726948 => S 32 7.3052, E 115 51.3828 ...
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0answers
214 views

Automating the production of GPS-compatible map tiles from georeferenced raster maps

I have a set of TIFF maps that I want to load onto Garmin GPS 62s units. The maximum size for each tile on the GPS is 3Mb and less than 1 million pixels. I manually produced one tile, following this ...
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1answer
54 views

GPS suitability

I was wondering what type of GPS/GNSS receiver should I use for recording and mapping trees in a particular farm (inventorying trees). Will handheld GPS like Garmin do the job? Or should I go for the ...
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0answers
66 views

Why are 10-bit linear feedback shift registers (LFSR) used in GPS?

The fundamental frequency of the GPS L1 signal is 10.23 MHz, which is related to the fact that the C/A code length is 1023 chips. This number comes from the fact that the codes are produced using ...
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2answers
593 views

Accuracy vs Precision GPS

I am doing some research on consumer grade GPS accuracy and precision. I took 5 readings for 20 known locations (100 readings). Am I correct in assuming that the standard deviation between the 5 ...
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0answers
81 views

select by attributes in modelbuilder while using iterate?

I have crated a model that iterates GPX-files from a folder and works through it and gives me a raster as output with pixel values after how many tracks passes through each pixel. This works the way ...
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1answer
195 views

How does TomTom store trackpoint information on its internal drive?

How does TomTom stores tracks and trackpoints on its internal drive? I maintain an open source computer forensics tool and would like to extract the data from both files and unallocated space. My ...
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1answer
121 views

How to convert distance into latitude + longitude [duplicate]

I have start point (latitude) I know direction, lets say strictly north, and I want to calculate latitude which is 100 meters above the start point. The same for longitude. I believe there should be ...
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4answers
320 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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0answers
237 views

how to combine GPS track logs using modelbuilder?

I'm creating a model to import GPS tracks(.GPX files) into ArcMap, this is to create a network of driveable off road vehicle routes. I've manage to do some of the things I'm trying to do, but there ...
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1answer
80 views

How can I change the coordinate system of gpx-points?

I'm working with qgis, v. 2.0.1. I have some points from a gps device (Garmin) and they already are in the .gpx format. Now I have two problems: First, I can't open the gps-Points with the "gpx-tools" ...
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8answers
23k views

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 ...
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1answer
882 views

Is there an industry-standard official mapping of GLONASS satellites to “PRN” values?

In the U.S. GPS system, satellites are uniquely identified by the PRN number broadcast by each satellite. This ID is usually visible on most GPS receiver platforms that provide access to individual ...
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2answers
95 views

Finding points that are within a set distance of other points

I have a large point file: several thousand. They are all GPS coordinates, recorded at different times, by different people. Many of them have unique data. So, for example, there will be one ...
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2answers
3k views

How to capture accurate GPS points using mobile devices?

I'm currently working in Vietnam as a climbing guide, but am putting my GIS skills to use by doing a side project for the company involving the mapping of climbing routes. Along with another employee ...
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1answer
184 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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0answers
94 views

Why Does Cold Start Take So Long?

I know very little about how GPS works. I noticed that after disabling GPS mode for a few days, even while standing on a street in the city, it can take several minutes for GPS to show my location, ...
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1answer
207 views

how to create a network from gps tracks?

I'm trying to build a network from several GPS-trakcs, to digitalize hiking routes on my land. I have several GPX-files from routes I've tracked with the gps. I managed to display them in Arcmap ...
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2answers
211 views

Is there a consumer-level handheld GPS that can use standard GIS data as its background layer?

I'm shopping around for a handheld GPS, and from what I'm seeing, none of the big vendors (Garmin, Magellan and Delorme) make a unit that can use, for example, a simple georeferenced TIFF or a ...
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2answers
2k views

GPS Module Without Velocity or Altitude Limitations

I am looking for a GPS module that I can use in a high-altitude project. The problem I have discovered is that GPS manufacturers are required to place a set of restrictions on GPS modules. The ...
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0answers
211 views

Can I use ArcPad 10.2 on a Trimble GeoExplorer 6000 GeoXT without GPSCorrect or NMEA?

I was tasked today with setting up two GeoXTs today with ArcPad 10.2. Everything was going well until I tried to connect to GNSS and the errors erupted. I looked into it, and our GeoXT doesn't have ...
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1answer
78 views

How to calculate “stop points” from a set of GPS tracklogs?

I have a set of GPS tracks pertaining to a cycling event that happened in the same day. I don't have much geographical information about the event itself, except for the tracklogs I downloaded from a ...
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6answers
7k 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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1answer
239 views

Data exchange from Terrasync to QGIS

What method could I use to import *.ssf files from Trimble GPS as features to display in QGIS?
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2answers
67 views

Finding routes in which more than one car passed (gps data)

I'm using ArcGIS 10.1. I have point GPS data of routes of several cars over a few days, and I want to find only the routes where more than one or two different cars passed through (Each GPS points ...
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2answers
128 views

Osm2po : Querying generated table to get the closet line from a point

I generate the OSM data of Africa postgis and I want to launch queries for a list of gps points to project them into the closest line. I made this request to a single point but took around 3 ...
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0answers
65 views

Location Data in TAIP Format to Geoevent Processor

We are testing whether we can get the surveyed cordinates in a Trimble GPS transferred online via TAIP format ( Trimble exchange protocol) to ArcGIS Geoevent processor . For this , one main concern ...
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32 views

GPS Coordinate Handling

I have a text file with consecutive coordinates of gps data for ongoing and incoming route(on Same road). i want to convert them in line format. how can i normalise those extra coordinate so that i ...
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1answer
89 views

Aligning two layers captured in different coordinate systems

I have two layers, one of points (locations of fruit trees) and one of Atlanta zip codes, in an ArcMap, but the layers are not aligning. The zip codes are in the top right and the fruit points are ...
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2answers
1k views

What class/types of smartphone chipsets support GPS, A-GPS, GLONASS AND have extended kalman filtering?

I've been testing several Android phones (all running Android 4+) Sony Xperia T, Moto G, Nexus and HTC 1 which are all giving decent tracks (all of which use GPS/GLONASS) However we are also using ...
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2answers
1k views

Why is the GPS Reference Meridian 100m to the East of the Prime Meridian?

Apparently if you stand at Greenwich then your GPS will not say you are at longitude zero. This is because the GPS reference meridian is about 100 metres to the east of the prime meridian. My ...
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0answers
122 views

How WiFi can tell my exact location? [closed]

There is no GPS installed in computer PC/laptops. Please let me know how WiFi can show my exact location.
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0answers
115 views

GPS tracking in ArcGIS Engine application

Is there an ArcGIS api for ArcObjects /.Net that I can use to build a function in an ArcGIS Engine 10 application that allows me to track a GPS signal and display the movement plus lets me export and ...
0
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1answer
41 views

European route E4 in geodata format

Good morning, Has anybody locate any kml, shp or gpx file with the complete European trail E4 ? Lots of google search navigates me to nowhere ... Dimitris
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101 views

Interpreting U-Blox GPS receiver data

Currently I'm writing software for a simple device for car, which will compare car's location to database locations and alert user. I'm using U-Blox 5 series GPR receiver. Reference manual is here. ...
5
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1answer
546 views

What is required for post-processing differential correction? (And can Garmin units provide it?)

2 very closely related questions about differential correction with a Garmin unit: 1). Some data was collected using a Garmin GPSMAP 76Cx unit and the data collectors are interested in whether ...
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0answers
117 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' ...
12
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2answers
922 views

How do GPS/Glonass/Galileo satellite know their position?

We use satellites to calculate our position. How do satellites know their position if it is right or wrong ? I have heard that the base station records and corrects the satellite path but how do they ...