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

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2
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1answer
223 views

How to get all gps points on a road from osm data?

I'm trying to extract gps points on roads in a region. For each road, I need a gps point on that road every 10 meters. I'm aware that Google Map API offer such way points, but due to the ...
16
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8answers
6k views

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 ...
1
vote
1answer
64 views

Method to determine a person's city/state using location coordinates?

I am working on data-mining project where I have to map a bunch of tweets to US states. I can get the lat/long coordinates from the tweet json, but I am not sure if it is possible to map those ...
1
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0answers
68 views

GPRS data receiving in Java [closed]

i am creating a java program that will receive data from GPS tracker device and will store it in MySQL. for this purpose i need to create a GPRS connection for receiving data. Can anyone help me how ...
2
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0answers
48 views

Can I read ephemeris data from GPS receiver?

I want to filter the GPS data. when I use the low cost GPS receiver, it gives erroneous data. therefore I want to apply some filtering technique. How can I read ephemeris data from GPS receiver? I ...
1
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1answer
109 views

Average stationary position with GPS

Is it possible to average a stationary position with a GNSS (GPS, GLONASS...) with a centimeter accuracy without external corrections (like differential or RTK)? If so, how long does such averaging ...
2
votes
1answer
260 views

How to compare GPS absolute positioning receiver accuracy

I have two different types of GPS modules which are in absolute positioning mode (pseudorange data) Lets say one of them is attached in microcontroller (such as arduino, rasbpy, etc) and the other ...
22
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6answers
5k views

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 ...
0
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1answer
416 views

Accuracy of GPS and HDOP

Given a handheld GPS with an accuracy of roughly 2 meters (verified through field tests) and an observation with an HDOP of 1.2, the accuracy of that one observation should be within 2 meters X 1.2 of ...
4
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1answer
257 views

Calculating Distances between coordinates

I have 75 coordinates in WGS84 that I brought in from an Excel table. They are now on my imagery basemap spanning across about a half mile on either side of a dirt road in Prescott National Forest in ...
3
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3answers
86 views

What view of sky is required for RTK GPS

When using RTK or differential GPS technologies, considering the Base has a clear unobstructed view, what view of the sky is required to be able to get an accurate fix with the rover when is moving ...
0
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0answers
45 views

Python GPS Observation Equations

I've been trying to write some code that will take pseudo-ranges and satellite positions and then compute the observer's position. I've been trying to follow through this book, but the crucial stage ...
1
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0answers
19 views

Plotting GPS plot without uploading data

I'm not sure if this is possible or not, but I'm wondering if its possible to plot a GPS dataset without uploading the data first to CartoDB. I've been analysing some data by uploading the postcode ...
1
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0answers
22 views

What is the lowest and highest possible pseudo-range?

I am trying to compact the required data that needs to be sent to the server to post-process the receiver's position. To do this, I figured it'd be possible to offset the pseudo-range by a fixed ...
0
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1answer
27 views

Entering Track from Garmin to GIS not getting basemap and orthomap to line up with Track?

I collected a GPS path on a flight and I would like to condense the path to the place where we landed and took pictures (condensed area at base of map; I want to delete the other part of the line). ...
3
votes
1answer
40 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
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1answer
382 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
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0answers
88 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
34 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
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1answer
81 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 ...
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0answers
78 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
52 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
44 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
vote
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 ...
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1answer
136 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
525 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
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0answers
147 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
23 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
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2answers
206 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
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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 ...
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
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2answers
415 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
104 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
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0answers
32 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
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1answer
150 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
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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
25 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
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0answers
41 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
452 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
257 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
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3answers
5k 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
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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
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1answer
51 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 ...
4
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2answers
178 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 ...
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0answers
51 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 ...
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0answers
79 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
35 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 ...