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13

They look like Degrees Decimal Minutes (DDM) with the degree and minutes symbols dropped. Try reading Lat 4531.38153 Long 12347.2328 as Lat 45° 31.38153' Long 123° 47.2328' You may find this PGC Coordinate Converter useful.


7

For the latitudes and longitudes, you can divide the numbers by 11930465 (2^32 / 360) to get values in decimal degrees. The values seem to be stored in a signed 32-bit integer range, to represent the full range of geographic coordinate values possible. Here is a link to a related question: Convert Garmin or iPhone weird GPS Coordinates


5

If you divide those "strange" latitudes and longitudes by 11930465, you get the North and East degree values you expect: But don't ask me why ;-)


5

As you said, differential correction is based on the correction of the position of EACH satellite viewed in order to compute a new position. So I confirm that it is NOT possible to do differential correction if you only have the coordinates, even if you had the exact time. If you want to improve the precision of your measurements with a unit that does not ...


4

The Garmin World base map is very abstracted, so I would not give much on accuracy of that map. You can try a free Openstreetmap built map for Garmin units of your region, and see if the offset remains. You don't have to put it on the unit itself, they work with Basecamp as well.


4

ArcMap 10.x has a tool for creating KML files directly. The kmz files created by the Map to KML tool in ArcMap 10 can be opened in Google Earth but do NOT work directly on Garmin GPS units. This is because the image format required by Garmin is JPG, and the image saved in the KMZ file is a PNG. A workaround: Create your map document, then run the Map to ...


4

There really isn't a simple answer to this. Primarily because you cannot simply convert a distance in feet to 'degrees' like you could feet to meters. The distance between degrees of latitude are generally constant across the globe but the distance between degrees of longitude varies according to latitude since they converge at the poles. If you want to ...


4

RTK is for real-time centimetre-level accuracy. I don't think that you need such a bazooka to locate trees in a farm (I assume that those trees are isolated if you talk about a farm and not a forest). Furthermore, RTK relies on signal emitted from a ground based station which might not be available in your area (especially if it is mountainous). On the ...


4

I found that (not surprisingly) the waypoints are found in all of the .gpx files whose filenames start with "Waypoints". I also found the function plotKML::readGPX to be the most intuitive for me. library(plotKML) setwd('/Volumes/GARMIN/Garmin/GPX') # identify gpx files that contain waypoints files <- list.files(pattern='\\d\\d.gpx$', full.names=TRUE) ...


4

I suppose it might be NMEA. It has quite strange coordinates representation: lat is DDMM.MMMMM and lon is DDDMM.MMMMM.


4

It's necessary to include the -t option to force simplify to operate on tracks: gpsbabel -t -i gdb -f ContDiv.gdb -x simplify,count=475 -o gpx -F ContDiv3.gpx Note that your coordinates should be in EPSG:4326, and the track should be a single segment.


3

Choose "Save as" -> "GPS eXchange Format (GPX)":


3

Only vector points/lines can be uploaded on a GPS unit transform polygons into lines using Vector – geometric tools – polygons to lines Convert .shp layer into a .gpx layer (GPX is a default format for GPS) the names of the points/lines of your layer must be listed in a column called “name” in the attribute table of the .shp file. GPS won’t recognize the ...


3

The video files recorded with garmin dash cam 20 are RIFF AVI files . There is a GR20 chunk in the file which contains sequence of 36 byte length binary data. Each 36 byte is about a frame, in this order: bytes |type |description ------+--------+---------------------------- 0-4 |int32 |Frame number 6-8 |int16 |Speed in Km/h 8-12 |int32 |...


3

There are a couple solutions I can think of, but based on what I was able to find on the Dakota 10, neither is applicable because the device doesn't support them. We would prefer missing over wrong positions. This can be done in more advanced GPS units by position filtering. GPS uses a measurement called Dilution of Precision (DOP) to measure the ...


3

Yes it is possible to create a custom basemap for a Garmin unit. It isn't straightforward or well documented. It definitely isn't supported by Garmin. There are a few ways of doing it, but the steps I used involve these software: GPSMapEdit - import shapefiles into a Polish Map format file http://geopainting.com/ Cgpsmapper - convert the Polish Map Format ...


3

The reason why you do not see the length in the attribute table is that the length (and area) of features are implicit attributes of their geometries. They are not stored by default, they need to be calculated. If by cumulative distance you mean the total length of the line, you can get that value by creating a new field in the Field Calculator using $...


3

I hope this may help you. I did some research on Sri Lanka coordinate systems at spatial reference. I found some crs that may apply to your problem. For testing purposes I used EPSG 5324 (Kandawala / Sri Lanka Grid) SR-ORG:7765 : +proj=tmerc +lat_0=7.000480277777775 +lon_0=80.77171111111112 +k=0.9999238418 +x_0=200000 +y_0=200000 +a=6377276.345 +b=6356075....


3

Yes, there is a Photos toolset in ArcGIS. I think what you're trying to do is create points from photo locations. To do that, use the Geotagged Photos to Points tool. Here's an article to Import Geotagged Photos into ArcMap.


2

I'm afraid you are lost with your approach. Although called .img file and "tile", this data is in fact a compacted vector format invented by Garmin, which is not supported by QGIS or GDAL. You can use them im QLandkarteGT, which has some GIS-like features, and Garmins own BaseCamp software. But nowhere else (except the Garmin units, of course) QGIS is ...


2

it is documented here: http://www8.garmin.com/xmlschemas/TrackPointExtensionv2.xsd. <xsd:element name="speed" type="MetersPerSecond_t" minOccurs="0"/> and type MetersPerSecond_t is defined as <xsd:simpleType name="MetersPerSecond_t"> <xsd:annotation> <xsd:documentation> This type contains a speed measured in meters per ...


2

There are a few speeds that can be immediately tossed out: 30 ft/s = 20 mph < 30 mph 30 km/h = 19 mph < 30 mph 30 yd/s = 61 mph > 30 mph (not exactly a standard measurement) The only other "common" speed I'd say is m/s, which works well: 30 m/s = 67 mph > 30 mph If you can confirm that elevation is given in meters (it looks like it is for ...


2

Some applications like the excellent GPS Utility make shapefile-GPX conversions very straightforward, allowing you to identify what the waypoint name field is directly, and to do a lot of editing (often needed for field navigation). The ability to down/upload to a variety of GPS models is also valuable (I have yet to have consistent success with QGIS for ...


2

You should be able to use the "GarminCustomMap" plugin to create the .kmz file, then copy the .kmz file to the /Garmin/CustomMaps folder on your GPS receiver's microSD card. Create the CustomMaps folder if it doesn't yet exist.


2

@AndreJ's answer is right. I just add the reason for this "strange" number : it seems Garmin stores its angular coordinates using a 32-bit integer, so that gives 2^32 possible values. We want to be able to represent values up to 360° (or -180 to 180), so each degree represents 2^32 / 360 = 11930465. So dividing your coordinate by 11930465 will give ...


2

I use GPX format to transfer data from and to Basecamp. The older version I use can also export csv, and import kml and csv. But since I use GPX for export to and from the GPS unit too, I prefer that format for all exchange. You can however not use the Garmin based .img files inside QGIS.


2

I think you need to activate your tracks from your track meny in your gps, The gpx file will create many tracks and each of them has to be activate manually. At least it works that way with other garmin gps modell.


2

Although not a tutorial or video, ArcMap GPS Support at ArcGIS 10.2 for Desktop seems to be well documented: A roadmap to the ArcMap GPS Support toolbar ArcMap GPS Support takes in a feed from a GPS receiver and displays the current location on the screen. You can also store locations from the GPS receiver in a log for archival or real-time digitizing ...


2

You have to download the PC version zip file, which contains a bunch of single garmin img tiles, including contour img tiles. Mkgmap needs all those single img files for merging: java -Xmx3000M -jar mkgmap.jar --show-profiles=1 --gmapsupp 3*.img OpenTopoMap.TYP The file you downloaded is probably the composite file, usually called gmapsupp.img. It would be ...


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