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

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102 views

Problem measuring area with gps coordinates

I am trying to measure area from gps coordinates but fail to get the correct result (7200 square meters). I used the formula from this post but I get way too high number as result (should be in square ...
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3answers
4k 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 ...
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2answers
2k 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
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1answer
46 views

How to change ODK GPS accuracy threshold?

I am using ODK with ONA in XLSForm. As the GPS accuracy default is 5 meters, it automatically accepts it when it reaches 5 meter. Is it possible to change the default accuracy to less than 5 meters ...
2
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1answer
136 views

Convert Garmin or iPhone weird GPS Coordinates

I am trying to find a way to convert over 500 locations I have saved in my Garmin iPhone GPS app (iPhone 4S using Garmin StreetPilot v2.7), but I can't find a way to convert these coordinates as they ...
2
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1answer
553 views

Converting GPS Positions to Google Maps

I have a set of GPS-coordinates in a database, which I want to compare to a coordinate supplied by the html5 location API. My coordinates look like this: <WGS84Coordinates> ...
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1answer
221 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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2answers
566 views

Webservices for GPS (Upload on DB and display it)

i'm doing an application where my users would be able to upload their gps tracks. My idea is to put their tracks on mysql database and display it on appropriate map. Question:How can i do that? My ...
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1answer
242 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 ...
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2answers
46 views

How do some companies receive GPS data from vehicles if GPS's can't send any data?

I know that some companies offer tracking services for vehicles such as live GPS tracking they can access any time, but as you can't use the GPS protocol to send any data i wonder how the do it... I ...
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1answer
93 views

Why are my DMS points plotted way off from their true locations?

I'm having a bit of a nightmare plotting some GPS coordinates in QGIS. My coordinates came from a PDF so it took a little wrangling to extract the from the PDF and convert them to a CSV file. I've ...
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2answers
92 views

What gps app to use for mapping bus routes?

I'm looking for a GPS app for android to capture waypoints and lines. I'm going to map the route buses and the stop points. Which GPS app is recommended for marking “points” and marking the “lines”? ...
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4answers
409 views

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
142 views

Calculating countries flown over on flight path

Say I have two airports given. I can then get their coordinates. Now that I have the beginning and end coordinates I can draw flight-path from the two locations. Now my question is that given two ...
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2answers
2k 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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1answer
110 views

What is a reasonable time to get a gps fix with 10 meters precision?

I hope I'm asking this at the right part of Stack Exchange. Please bear with me if I'm wrong. I'm developing some gps based applications. The demands I have for precision are not very high, but I ...
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2answers
355 views

Vehicle tracking by QGIS

I need to do routing for a vehicle. A map with detailed turn-by-turn driving directions should be generated. For example, it should be like car race game in which the map with vehicle tracking is ...
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1answer
78 views

Where would a perfectly vertical vertical tunnel through the earth come out?

I am a programmer. I have a point P1 (lat,lon) given by GPS (WGS84) and I want to know the location of a point P2 if I make a straight line from P1 to the other side of the earth. I have read some ...
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2answers
1k views

How can i convert from local coordinates to coordinates gps?

i don know if this is the right place to publish this. i am working with business object tool traying to make a kml file to be imported on google maps. I dont know much about geographic systems, but i ...
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1answer
354 views

Transformation from WGS1984 to ITRF2008

We are using Projected Coordinate System: Ain_el_Abd_UTM_Zone_39N (Transverse_Mercator) in our GPS Devices and have valuable Coordinate data. Can I change the projection of this data this to WGS 1984 ...
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4answers
135 views

Where to license non-automotive POIs for France, Spain and Portugal?

qualified POIs are needed for a commercial project - should cover broad out-of-car usecases (not needed: parking, gas stations). Could be commercially licensable data or derived from national geodata ...
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2answers
76 views

How can I find GPS coordinates of the geographic center of US counties?

How can I find a list of the GPS coordinates of the geographic center of each US county?
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2answers
101 views

Finding all ways that are partly within a bounding box

I'm trying to write a query that will return all OSM ways which are contained within a bounding box of min/max gps coordinates. I get these cooridinates from the greater london bounding box on ...
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2answers
164 views

How can I transfer waypoints and tracks from Base Camp into QGIS2.6?

I'm working on transferring all my field data from Garmin Base Camp onto QGIS. This is an attempt to overcome the learning curve from basic trail GPS mapping programs to the real thing. I'd like to ...
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1answer
59 views

Coordinate display in Terrasync

I'm using Terrasync on a Trimble GeoXH 6000 - set for WGS 84 and UTM. It acquires satellites fine, but instead of displaying my current location in UTMS, the skyplot screen shows "12RVU" and then a ...
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1answer
278 views

How is Precise Point Positioning (PPP) exactly done?

I am looking for a positioning accuracy that is higher than normal consumer-grade GNSS receiver (mostly GPS/GLONASS hybrids with +- 5m precision). I came across RTK with dual receiver setup (base ...
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1answer
167 views

Accuracy issues between data in QGIS and Google Earth

Wondering if anyone can answer this question. I have a kml in Google Earth. When I import it to QGIS, and then import the Google Earth images they are in slightly different places. I used a QGIS ...
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1answer
81 views

Most accurate GPS hardware for less than 1 mile radius [duplicate]

I apologize if this is a duplicate but I can't find a good answer or area to know where to find the correct answer. I am looking for the technology or hardware around wearables or similar technology ...
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1answer
4k views

Looking for an android solution for offline kml/kmz file viewer with gps support

I have some KMZ files of cadastral maps. I need to fiscally go to the boundaries of my lands (parcels) and take a look at where they are with the gps and maps support. Some of these places are not ...
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1answer
65 views

Adding GPS tracking data from Excel into QGIS

Sorry if this is an easy question! I have added GPS points in QGIS however all of them are the same colour. I want the points to be coloured differently for each individual. How do I do this? Thank ...
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2answers
111 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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4answers
181 views

Linking up GPS points taken from rail network

Bit of a newbie here, trying to work out whether any PostGIS functions can help with my task. Apologies in advance if my use of GIS terminology is not up to scratch yet. I have a large database of ...
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1answer
114 views

How to Deal with Overlapping Coordinates in Statistical Analysis

I decided to make an archaeological map about certain tombs distributed in the area of Crete and make some statistical analyses using the spatial statistical tools of GIS. Specifically, I'll be ...
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1answer
219 views

QGIS: Colour GPS track by speed

sorry íf I might ask this question the 101 time, but I didn't found anything with google or SE. I have a CSV file with WGS84 trackpoints and visualizing them with QGIS textplugin works fine. The log ...
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1answer
1k 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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1answer
131 views

Pathfinder Differential Correction: “Use reference position from” who?

How do you choose either "base files" or "base provider"?
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2answers
937 views

How to find the Shortest Path between two coordinates points using pgrouting A-Star?

In PostGIS I have two tables: an osm road network and a table that contains the start and end coordinate points of each path (i.e. userid, start_x1, start_y1, end_x2, end_y2). I would like to know: 1) ...
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1answer
135 views

interfacing multiple gps

I am trying to interface NMEA output of multiple GPS units transmitting wirelessly to a single PC, each GPS position can then be shown on georefance map of that area. My question 1.) How to ...
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1answer
588 views

Snap Polygon vertices to Point features

I have a set of polygons drawn using an inaccurate GPS PDA. these polygons are sharing nodes. after post-processing GPS data to get accurate coordinates i have a set of all the nodes, then i have to ...
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2answers
575 views

How to convert Garmin Waypoints to Google Mercator?

I have georef some topocards with QGIS and the Google Hybrid Layer. So, this cards are connected with the Google Mercator System. Now I have some waypoints taken with Garmin GPSmap62 (in WGS84). ...
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1answer
136 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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1answer
30 views

Topology Editing using ArcView (now called Basic) license level of ArcGIS Desktop?

I am building a geodatabase from data collected on a GPS handheld in the field. The GPS device collects decently accurate information but I need to make sure all the polygons, lines, and points are ...
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1answer
67 views

How to find if two gps tracks were from the same trip?

Given I have gps tracks from many users running or hiking, how can I find out who were running together? In other words, which algorithms are there to find out who were in the same party? Haven't ...
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1answer
192 views

Bind GNSS receiver with android app over bluetooth

I'm looking to integrate a GNSS receiver with a Smartphone app. I've found only GNSS receivers that are meant to communicate only with their mobile interface, they don't provide any documentation for ...
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1answer
73 views

Mobile device GPS into a PDF Form

This is an issue I've been trying to solve for a while and am told it's not possible. I have made a PDF form with an input box for coordinates. As the form is for use on mobile devices, I would ...
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1answer
177 views

Converting GPS cords to X Y based on wrapper

I'm trying to create some software for an airport and they require me to place icons of aircraft in their position based on GPS. I have 10x10 tiles each tile being 256x256 pixels and the origin point ...
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1answer
94 views

How to detetmine county of GPS coordinate?

I have a SHP file that contains all counties in the USA. I also have roughly 100 million GPS locations. I need to tally the number of GPS locations per county. A linear search through the counties ...
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1answer
46 views

Mobile GPS location and CAR GPS location showing different outcome

I want to make a CAR positioning system. I wrote a program which can show me the coordinate locations on a map. But when I get coordinates from MOBILE GPS and from CAR GPS, they both differ. Why ...
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1answer
79 views

Calculating the fastest routes and some points on the same time

I have two drivers and each driver has a set of about 15 locations where they need to drive to on a single day. Calculating the shortest route for both drivers is not the problem (using a matrix ...
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1answer
312 views

Is there any information in Sky Plot that is not in DOPs chart in terms of predicting accuracy in the field? (GPS data collection planning)

Joe only looks at DOPs chart and weather report for mission planning. Moe looks at both DOPs chart and Sky Plot and weather report. Is Joe missing out on something relative to Moe in terms of ...