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

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3
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1answer
38 views

problem with the import of a gpx file in any program

I have difficulties to import one particular gpx file. I got it via email and it displays some tracks. 10 segments and 5500 waypoints. i tried as follow: QGIS, also with GPSBabel Google Earth ...
1
vote
1answer
374 views

Trimble Net R9 Base Station Receiver File Structure

We just installed our new GPS Base Station Net R9 receiver that replaced our old 5700 receiver. The old 5700 used Trimble's GPS Base software, which the new Net R9 does not. My first problem that I ...
2
votes
0answers
64 views

Find gravity normal by ECEF or GPS coordinate of point

How to find gravity normal by ECEF or GPS coordinate of point? Is it the same as normal to elipsoid? Is this ordinary way to calculate normal to ellipse? I'm not quite sure which altitude is ...
0
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1answer
33 views

How to set datum in GPS connection setup window in ArcFM Viewer for ArcGIS Engine Application

I have a custom application based on ArcFM Viewer for ArcGIS Engine. I want to use an external GPS receiver with that application and the setup window does not let me choose a different geographic ...
2
votes
1answer
64 views

Setting elevation data for tie points in Pix4D

I am currently working in Pix4D and am trying to assign elevation data to my selected tie points. I have aerial images taken using a camera with GPS from an aircraft and am working with a fairly ...
1
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0answers
77 views

Determining accuracy of coordinates from handheld GPS?

I'm working on a project for class, and I'm mapping GPS on Google Earth with a KMZ file. I used a handheld GPS 24°6.691'N + 74°27.833'W. How accurate is my coordinates? I know I'm in decimal ...
11
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10answers
4k views

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 ...
0
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0answers
47 views

How to create speed maps with gps data

I am looking to create a speed map from gps data, one of the problems is that the data overlaps due that the road is a track. How can be the best way to plot this map? I have Qgis and ArcGIS options ...
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0answers
37 views

How can I calculate times with gps data using random points on the track? [closed]

I have GPS data from a car that is circulating all the time in a closed circuit. I need to put a few points along the route, about 3 or 4 and calculate the time it takes to get between points. These ...
1
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5answers
2k views

Solutions for uploading maps to GPS (forestry maps: roads, trails, hydro, polygons)?

I'm using a QGIS 2.2.0 Valmiera on a Windows 8.1 system Desktop. I'm a forester and I would like to have a cheap solution to load maps into the handheld Garmin 60, 62 or 64 series GPS. Free would be ...
1
vote
1answer
106 views

GPS tracking times

I have a GPS data on a closed road, where the cars riding laps, and I want to know how long takes to do 1 lap and also I want to add some points to calculate how long takes in specific sections. One ...
1
vote
1answer
488 views

GNSS planning online vs trimble planning 2.9 software

Why using the same parameters GNSS planning on-line and Planning 2.9 Trimble show me different Dilution of precision (DOP on the graph)?! Which program is better mission planning solution for GNSS ...
1
vote
0answers
125 views

Post-processing GPS Satellite Measurements

I am working on a system that reports its location to a server using very little power. In order to achieve an extremely low power usage, I am avoiding having to download both the almanac and the ...
1
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0answers
20 views

Filter GPS tracks to determine “Moving Time”

I am working with GPS tracks of outdoor activities, think cycling, running, hiking. These activities often have "rest periods" where people take a break, wait at traffic lights, or just stopped their ...
3
votes
2answers
197 views

QGIS Real-Time Vector Layer Creation

QGIS is running on my Windows PC. I have a CSV file on my PC that is remotely updated with values of a raspberry pi's GPS position and some wifi-status readings. Is it possible to create a vector ...
16
votes
6answers
3k views

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 ...
30
votes
6answers
2k views

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 ...
38
votes
9answers
53k 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 ...
7
votes
2answers
5k 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 ...
2
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0answers
45 views

Convert xyz coordinates to lon/lat to calculate height change GPS time-series data [duplicate]

How can I convert the XYZ coordinates in Lat, lon to calculate height in metric system? XYZ ascii site YYMMMDD yyyy.yyyy __MJD week d reflon _e0(m) __east(m) ____n0(m) _north(m) u0(m) ____up(m) ...
2
votes
2answers
401 views

In hyperbola model of how GPS equations are solved, why do 3 satellites give only 2 hyperboloids and 4 satellites only 3?

The Hyperbola depiction of how the GPS equations are solved: From several psuedoranges measured at the same time, we can calculate the (absolute) difference in the distances between us and these GPS ...
2
votes
1answer
92 views

Importing xyz text ascii GPS time-series for velocity visualization using QGIS?

How i can import text ascii xyz gps time-series in QGIS for velocity visualization? Example xyz MLBU 07SEP17 2007.7098 -0.119998752351520E+07 0.626106994328102E+07 -0.199557178074915E+06 ...
2
votes
0answers
29 views

Why time differs between gps and ntp exactly 90 seconds

EDIT: This question can be closed due to figured out the problem was in the NTP configuration. While the gps device is no gps data received, gps device is send gps time to server as zeros ...
0
votes
1answer
111 views

Rounding Coordinates

If you want an accuracy of seven digits, should you then round to that value or simply just cut the numbers after that? Example: 51.1936137567 to 51.1936138 or 51.1936137567 to 51.1936137
2
votes
2answers
3k 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 ...
0
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0answers
24 views

Live GPS tracking with both ping script

That's a professional context : During a travel between two train station, I would like to use the live tracking and analyse the network performance (access by Wifi & 3G/4G ). I would like to ...
1
vote
0answers
40 views

Turning QGIS Map into real time GPS for phones?

I'm attempting to create a map in QGIS for use on a website that will allow users to navigate pathways in a park (i.e. choose a desired location, and be shown directions). I'm done with the map ...
1
vote
1answer
443 views

How to improve accuracy or extrapolate missing or bad GPS points

Is there an easy to use freeware tool to postprocess my location data, in order to correct 1) location errors (or improve accuracy not based on differential GPS correction) and 2) deal with missing ...
2
votes
1answer
239 views

Calculate road distance between GPS points

I am working on tracking system that track location of vehicles on the map and tell their total distance from the beginning till today. I have device_id, timestamp and GPS location in the table like ...
4
votes
3answers
4k views

Measuring polyline using either QGIS or ArcGIS Desktop?

I've collected a bunch of GPS polylines (WGS84). What is the easiest way to measure the length of these lines in KM using QGIS or ArcGIS Desktop?
4
votes
4answers
5k views

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 ...
0
votes
1answer
43 views

Connect a Garmin and fetch GPS stream

I own a Garmin Oregon 600. I know that it has some communication capabilities, but I have not found on user guide how to use it. Does anyone of you know how to connect this device by USB/Serial in ...
2
votes
2answers
317 views

Android devices and apps with support for Galileo positioning

While the European's Galileo positioning system is only expected to be fully deployed by 2020, the first positioning made using already deployed Galileo satellites was made back in 2013. Also, ...
4
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2answers
166 views

Road segments reconstruction from GPS trajectories

We have a 10,000 base of vehicle mounted moving devices which report their GPS position on a time based schedule. All that data is currently being stored in our database for several business related ...
0
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0answers
45 views

GPS coordinates of a point between two known points

I am looking for an algorithm for finding GPS coordinate of a point on a straight line defined by say points p1 and p2 at distance r from p1. GPS coordinate of p1 and p2 are known. I searched a lot on ...
0
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0answers
70 views

Switching maps when zooming with Garmin GPSMAP 64s

I am using two different maps on my Garmin GPSMAP 64s, the Garmin GB Discoverer 1:50k map and the Talktoaster (OSM data based) map. As I am sure everyone knows, the Discoverer map looks rubbish when ...
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0answers
34 views

Find Minimum Bounding Box for a set of coordinates [duplicate]

I am working with GPS tracks (lat/lon values) and my goal is to compute the minimum bounding box for a small geospatial library I am working on. The datasets are not huge, maybe a couple of tens of ...
5
votes
1answer
384 views

Sub-meter Bluetooth GPS units and ESRI Collector App

We have been using Trimble XT/XH for years now, but we are at a time when we need to upgrade and do not want to drop another $8000 for another Trimble that only causes us headaches and not very user ...
0
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0answers
22 views

Valid Range of Geoidal Separation in GNS and GGA sentences

I haven't seen any information about valid ranges of geoidal separation in GGA and GNS sentences. I am using Nema Studio Simulator to simulate GPS receiver. In there Geoidal Separation can be set to ...
22
votes
5answers
36k 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 ...
11
votes
4answers
3k views

Bluetooth GPS to Smart Phone

Has anyone had any luck intergrating a GPS unit with your Smartphone? Looking to gain sub 5m accuracy. Ideally would like the phone to just use the better gps reciever when it is connected. This ...
1
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0answers
20 views

Is there any standard or source of information to check for valid ranges and accuracy of each information conveyed in NMEA format ?

Currently I am reading IEC 61162 Nmea 0183 standards document. In there there is not information about valid ranges of some values or precision of data fields in nmea sentences. Is there anywhere that ...
5
votes
5answers
241 views

Detecting and fixing outliers in a GPS trajectory

I need to find an algorithm or method that can detect outlier latitude longitude points in a trajectory during post-processing, which can then be fixed (brought back into the trajectory's path based ...
3
votes
1answer
62 views

How to generate missing points in GPS trajectories?

I have some GPS trajectories that include gps locations recorded on variable frequencies (every 1 min ,5 min , 20 min,etc.)using a geographic projection WGS84. In my work, i need a fine-grained GPS ...
9
votes
2answers
7k views

Low-cost centimeter-level accurate satellite positioning (GNSS/GPS) [closed]

I am looking for a low-cost (< US$500) GNSS/GPS setup with a centimeter precision without much HW hacking. I am not able to produce my PCB or do any soldering (though I would do that if there is no ...
3
votes
0answers
177 views

Import GPS SINEX (for velocity analysis) into Sarscape or processing with others software

I try to import GPS snx. into Sarscape 5.2 (use GPS Import tool) and getting error 115) ) gps_type : [sinex] 116) ) generate_kml : [OK] 117) ) generate_shape : [OK] 118) ) ...
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2answers
55 views

Matching Street names with GPS data?

I have a list with over 10000 street names and places. These street names indicate where Radar Speed controls are located in Germany. I Need to have a map, where those Points are tagged. I did this ...
1
vote
1answer
45 views

Is OpenStreetMap suitable for me?

I'm planning to create a map with GPS and routing support as well as other custom features for my local area. It will be for a commercial usage. I'm okay with showing OpenStreetMap logo in my app. Is ...
1
vote
0answers
41 views

Correctness of Measurement

I tried Google, but the questions isn't that easy to put in Google, so I haven't found anything about this. I am making a database with different locations (latitude and longitude). For this I have ...
1
vote
1answer
74 views

Calculating emissions from points in road network using ArcGIS for Desktop?

I have GPS data (X,Y, speed, CO2 and fuel consumption) for one truck for one trip. I want to import them in ArcGIS and to join them with the road network (map matching). I was thinking of applying ...