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5

No, GPS does not 'correct' for continental drift per se. GPS can be (and is) used to measure drift. Drift is accounted for in the model of the earth used, aka datum or reference ellipsoid. GPS uses the World Geodetic System, or WGS, and most units report coordinates in the initial version established in 1984 (aka WGS84 coordinates). That model, and others ...


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Something like DBSCAN as an algorithm could help python implementation or DJ Cluster algorithm. Have a search for DJ cluster. A kdtree would also allow you to do a nearest neighbour lookup. Finally, there are functions, and spatial index's in PostGIS that you could use.


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According to this page, the latitude and longitude values could be in (1) degrees, (2) degrees and decimal minutes, or (3) degrees, minutes, and decimal seconds. In your example, (2) is a decimal value and (3) is zero, so you have degrees, decimal minutes. So, you'll have to some checks on the three values to determine which format is being used.


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Try MapIt - excellent tool for spatial data collection. https://play.google.com/store/apps/details?id=com.osedok.gisdatacollector. More detail can be found here: http://mapit-gis.com Mobile asset collection & management Survey layers (point, line, polygon) Attributes management Google Maps, Bing Maps, Open Street Map base maps Offline maps and ...


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The following workflow is for QGIS and will give you the mean distance from the route for each transect in metres. I'm assuming the data will be using a projection in metres. Buffer your transects and route, for example, by 1m with Vector > Geoprocessing Tools > Buffer(s). You now have two polygon layers - the transects and the route. Give the route ...


3

I think Hausdorff distance may be what your looking for. It's basically a measure of how similar two geometries are. General steps to apply it to this problem: Find the closest point on the track to beginning and end of each planned segment. divide the track into segments between these sets of points. Calculate the Hausdorff distance between the planned ...


2

from the above example, I suggest that you 1) create points along the green lines at a regular interval 2) get the perpendicular distance from those points to the blue line and, finally, 3) compute the average error based on those distances. Note that you could reject points that are too far (above a given tolerance for GPS worst precision) due to the ...


2

(This answer addresses the comments of John Barça’s comments… a little too large to put into the comments section). Again, I got this to work using PhoneGap, but I should perhaps clarify things a little bit. 1) I used PhoneGap Build instead of installing PhoneGap on my computer (glad to have a workmate who can give me this great kind of advice!). You will ...


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If you wish to use HTML5, you are probably better off using PhoneGap. PhoneGap abstracts away the significant differences between the hardware and APIs on different mobile platforms, iOS, Android, Windows, etc, allowing you to use Javascript, CSS and HTML to access the sensors, such as GPS. See the supported features/sensors grid. You cannot otherwise access ...


2

Do you have ArcGIS? If so, you can follow these directions below and it will take about 5 minutes. Download US Counties from ESRI Follow ESRI's instruction at HowTo: Find the centroid of polygons using Calculate Geometry This results in a table of Latitude and Longitude attributes as well as points for the centers on your map.


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The county features in the geodatabases found here contain two columns (INTPTLAT and INTPTLON) that represent the centroid of the county. I used several state geodatabases but have not attempted to verify the accuracy of the centroids listed.


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Fulcrum is a cost-effective and customizable GIS mobile data collection platform. Includes a 30-day trial at sign up! http://fulcrumapp.com/ https://play.google.com/store/apps/details?id=com.spatialnetworks.fulcrum&hl=en


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Maybe you can find some hints and solutions in this blog posting by the developer of the OSM-based routing solution Graphhopper. His project with your aim is called Map Matching


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You can have a closer look at Miataru It seems to be an opensource and multi-platform solution, but I have not tried on my own, so please try to get special information from its website


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In GeoTools you can use the GeodeticCalculator for this sort of calculation: DefaultGeographicCRS crs = DefaultGeographicCRS.WGS84; GeodeticCalculator calc = new GeodeticCalculator(crs); GeometryFactory geomFactory = new GeometryFactory(); Point point = geomFactory.createPoint(new Coordinate(0.0, 50.0)); ...


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While looking for a similar device to determine birds position in flight, I found the TruPulse 360. This laser range finder gives you the information you need and it stores it directly on a computer. But as it's quite expensive and regarding birds probably only works for 500 m I am going to try the Solmeta Geotagger.


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You're likely to run into computational bottlenecks and consistency problems with any package that doesn't have a proper routing or at the minimum a road network abstraction. If you are using OSM data for the road network, check TrackMatching from my profile. Check this thread map-matching algorithms.


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What you are after is a good map-matching algorithm. There are very few available off the self: see explanation and description on OSM. In case you're interested in simply using an API for that purpose, have a look at TrackMatching on my profile.


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Would it be possible for me to add my own roads to my own osm MAP ? I have added my area of Ireland to a postgres database and I plan on using pgrouting for routing, but would it be possible for me to add any new roads I find to the data and for them to considered when calculating the shortest path ?


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Using two identical gps devices with one at a known location. Can't you work out the error for each gps reading and pass that error data on the the second gps unit and use it to correct the data ?


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So, it was because I hadn't specified that points should be stored in latitude and longitude when running osm2pgsql. The command I used successfully was osm2pgsql -c -l -s -d england_osm ~/Downloads/england-latest.osm.pbf


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For the routing part you can have a look into GraphHopper, customizable so you can find if one-way or not and your own algorithm and choice whats the best way, with turn by turn instructions, free - even for commercial usage and also available for iOS For the map part: I'm not sure - maybe you try openscience/vtm as it was once ported to iOS too Note: I'm ...


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These are results of tests carried out in October and December 2014. Tested were the following GPS telemetry, GPS data loggers and a hand held GPS. GPSFlight STX900e telemetry, embedded GPS unit ublox LEA - S5 BRB 900 MHz GPS Telemetry, Lassen IQ series GPS receiver TLA 900 MHz GPS Telemetry, ublox 6 series GPS receiver Holux 1200e GPS data logger ...



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