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

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7
votes
4answers
495 views

Is there a way to identify and remove similar GPS tracks in PostGIS or ArcGIS?

I have a large number of GPS tracks from a number of different users. I'd like to identify tracks that take the same route and remove those duplicates. For example, a user takes the same streets from ...
0
votes
0answers
34 views

A machine to measure latitude to 6 decimal places of a degree [duplicate]

I am doing a PhD research project to do with medieval and ancient archaeoastronomy which requires me to be able to measure latitudes up to an accuracy of 6 decimal places of a degree of latitude. ...
1
vote
0answers
2k views

convert GPS to XY coordinates

if i have obtain GPS coordinates as Latitude/Longitude, then i need to convert them to XY coordinates, i see this link actually i need to get the Trilateration , in its equation i need the XY ...
2
votes
1answer
267 views

Why are Garmin provided maps inaccurate?

Collected tracks on my Garmin GPS (Oregon 450) or in BaseCamp seem to be not in the correct position. There's only a little detail with major highways but it looks as though the route is shifted ...
5
votes
3answers
3k views

How to transform GPX-tracks into elevation-tracks with any GIS?

I have a GPS track in GPX format available from a recent bike tour and I need and want to do some analysis on the tracks. I'm wondering whether there is any way to transform the GPX data into an ...
0
votes
1answer
61 views

error in estimate distance?

i do some experiment place two sensor node between them 4 meter as distance. then i get these GPS information: node1: Latitude: 32, 33.255 , Longitude: 36, 0.6632 node2: Latitude: 32, 33.228 , ...
1
vote
1answer
712 views

find euclidean distance in GPS [duplicate]

i need to find the distance between two gps location, So i think to do this: lat1(seconds)-lat2(seconds)=lat * 30.7151 == distance latitude in meters =Latm long1(seconds)-long2(seconds)=long ...
1
vote
1answer
625 views

convert GPS to x,y using reference node

i am using sensor nodes and their antenna to calculate GPS coordinates as notation of (degrees/minutes/seconds), i have some question of how to do these things: how can i convert latitude and ...
1
vote
1answer
481 views

How to force ArcGIS iOS to use GPS data from External GPS device?

I created an app that will display the map and the location of the external GPS device. The scenario is using a wifly module to broadcast the GPS data of the GPS receiver in wifi. The app is now ...
0
votes
1answer
102 views

Imported GPS data does not overlap with map

I´m working on QGIS and I geocoded 2 addresses of a city in Germany and tried to input the text-file as a layer. It worked, but the 2 points must be in the map of the city and if I zoom to the ...
3
votes
3answers
206 views

How long for surveying quality GPS to get accurate 3D position information

I recently read an Ordnance Survey Blog article that seemed to suggest that it was necessary to leave the GPS device in use for four hours to gather requisite data. I am aware that "domestic" GPS ...
0
votes
1answer
244 views

ArcGIS mobile to use external GPS device

Im currently tasked to create an app that would sketch a GPS Device's movement and plot it on the ArcGIS map. By default, the ArcGIS locationDisplay class calls the IOS class CLLocation to retrieve ...
0
votes
1answer
620 views

How to calculate surface area of highland region using DEM with ArcGIS (ArcEditor)? [duplicate]

Am shyaka from Rwanda. I use GIS tools and have all required data to perform or calculate surface area from the polygons that have been given by GPS (Trimble) with ArcPad 8. I originate from a high ...
4
votes
0answers
799 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 ...
3
votes
1answer
957 views

Is machine learning used much in GIS?

I'm new to GIS. Is machine learning used much in this field, and where? I'm investigating a job opportunity with a mapping company working on traffic awareness. My background is in supervised machine ...
0
votes
0answers
168 views

Download/Upload GPS/Qgis don't work anymore

We were using Qgis and GpsBabel to download waypoints and tracks from GPS garmin 60 or 76. Since few weeks, this is not working anymore. There is a error windows, and nothing is created. I tried ...
7
votes
4answers
3k views

Garmin etrex raster maps support

I currently use an excellent set of printed topographic route maps for mountain biking. I would like to scan the maps, georeference them, and upload the maps to a handheld GPS device. Does the etrex ...
2
votes
0answers
382 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 ...
1
vote
0answers
41 views

Twitter live feed on ArcGIS desktop [duplicate]

I am a complete beginner with ArcGIS and i have been looking for a way to live feed tweets to ArcGIS desktop. A quick google search brings this blogpost up from 2009: ...
8
votes
2answers
1k views

How do I group near points with GPS positions?

I'm an IT person so I don't know too much about projections and so on, I hope you can help me. I have made an application for Android that collects a GPS position, so I have the latitude and the ...
0
votes
1answer
5k views

How can I manipulate the timestamps in a GPX file?

I have a GPS tracked stored in a GPX file. Now I'm looking for a tool that allows me to set the start time of the track and the duration, and the tool should automatically evenly distribute the ...
6
votes
2answers
1k views

Storing GPS tracks with timestamps in PostGIS

I need to store a series of GPS points with timestamps in the database (traces of various vehicles). I am wondering which of two approaches to choose for storing them in the PostGIS table: 1.) Each ...
1
vote
2answers
161 views

QGIS Holux gpx file doesn´t show up

I´ve got a problem with displaying the imported gpx file. The gpx file is created in Holux Funtrek 130 PRo. The map I use is from Openstreetmap, I am sure it is the right map from the location I ...
2
votes
0answers
110 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" ...
4
votes
1answer
218 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 ...
0
votes
2answers
323 views

I can not download gpx from GPS through GPS tool with GPS babel on QGIS

I have already install GPS tool plug-in and GPS Babel. Garmin GPS map 62s is connected my PC through USB cable. I changed device setting according to below site. ...
0
votes
1answer
58 views

Is it possible to download GPX another coordinate system except WGS(GCS) with GPS Tool on QGIS1.8.0?

I got GPS data with using bessel1841 as coordinate system. When I download GPX data on GPS tool, it is automatically treated as WGS84. Can I use another coordinate system when I download GPX on GPS ...
1
vote
1answer
219 views

Is it possible to see polyline as route or track data on GPS?

I would like to see polyline on GPS. First, I try to convert polyline to GPX. I uploaded GPX on GPS. SO far, I could not see the line on GPS. First of all,is it possible to see polyline as route or ...
2
votes
1answer
824 views

Where can I find Foursquare Datasets?

I'm doing research which aims to analyse location based social networks. So the Foursquare dataset is suitable for me. Is there any Foursquare dataset available? I need 4 information in the dataset: ...
5
votes
3answers
192 views

Can I access Trimble logged positions in ArcMap10?

We recently walked a fence perimeter with a Trimble Ranger, auto-logging positions at 5 second intervals in a generic point file. The exported file acknowledges over 800 points, but only displays the ...
0
votes
1answer
128 views

Alternate option for a Data Player plugin for GPS in qgis

I found a plugin for QGIS to play a GPS Track. (Data player plugin).The Problem is I can not read .gpx File with this plugin. Is there another option?
2
votes
0answers
152 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 ...
10
votes
3answers
764 views

Real time map matching using ArcGIS Desktop?

I am working on a project which requires real time map matching. I am currently using ArcGIS but not sure whether it will work. Here is what happens with my system: the cell phones sent GPS fixes ...
4
votes
3answers
581 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 ...
3
votes
2answers
312 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 ...
3
votes
1answer
286 views

Join GPS points obtained from .GPX file in Python Console

Having loaded the .gpx file into a new layer from python console, I'm unable to access the gps points in the attributes table. Essentially, i'm unable to join these points to form a polygon ...
7
votes
1answer
196 views

Unable to load .gpx file from Python Console

I'm trying to create a plugin which will extract the gpx files and load them onto the active layer window in QGIS. While I'm able to load it using the QGIS GUI from Layer>New Vector Layer, I'm not ...
5
votes
1answer
415 views

Why are points collected with a Trimble FM 750 off by more than a mile when displayed in QGIS?

I have a grower that has a FM 750 and is trying to make points in a field. When finished he takes the file out of the display and goes to his computer and he can bring up the points in the right ...
0
votes
1answer
1k views

How to fix the QGIS for Android GPS panel?

I have installed qgis on my samsung galaxy s1. But I cant test the gps. I found how to turn the gps on, but I cannot open the gps pannel to do it. When i press view->panels there is nothing happens.
0
votes
1answer
405 views

Looking for a tutorial on syncing QGIS with Trimble ProXT

Does anyone have any experience/advice to sync a TrimbleProXT gps antenna with the current "Lisboa" 1.8.0v? Additionally did you manage to collect features (points,line,polygons) in the field ok? ...
2
votes
1answer
2k views

Current time from GPRMC or GPZDA?

In GPRMC there is a time field, called fix time. Can I consider this always the same as value from GPZDA time? Is there any possibility that when GPS device is configured to stream both GPRMC and ...
1
vote
2answers
1k views

Exporting shp into a GPS [duplicate]

Possible Duplicate: How to convert .shp into .gpx using QGIS? I'm trying to convert a shapefile with some random points into a gpx file, but I'm having some problems: when I upload the gpx ...
5
votes
2answers
3k views

How to merge multiple file geodatabases into one file geodatabase?

I have created a file geodatabase that has several feature data sets, feature classes, and domains. I have created a map with the file geodatabase added to it, converted the map to ARCPAD AXF format ...
17
votes
4answers
23k views

What is the maximum Theoretical accuracy of GPS?

I was talking with a potential client, and they requested that we plot some points with GPS, with a maximum (or should that be minimum?) accuracy of 2 m. This is an area with no WAAS, and I was under ...
12
votes
2answers
531 views

Why does GPS altitude jump sometimes?

I am currently developing a little application in Android which uses GPS. When i click a button i start to record a "track". If i walk around i save my position every second into a file. This works ...
3
votes
0answers
288 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 ...
1
vote
1answer
1k views

GPS data validation

I was wondering if Fix quality data from GPGGA, can be substituted to Validity field in GPRMC? In my application I have to use only GPRMC, but I don't really know if it sets validity only if Fix ...
3
votes
4answers
5k views

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 ...
20
votes
6answers
5k views

How to create a polyline-based “heatmap” from GPS tracks?

This winter I am planning to track my downhill skiing/snowboarding using a GPS. Most of my riding will occur at the same resort. I would like to be able to create a sort of "heatmap" that shows the ...
3
votes
0answers
174 views

Are there any known problems using GPS connection in Android version of QGIS? [closed]

I install QGIS both my netbook (windows win7 starter) and My tablet (android 4.0). I can used GPS option in windows version and I can save location points from GPS. However, I could not manage same ...