gpsimportqgisshapefiletrimble
I had some field work with Trimble gps. I located some positions and I exported them as a shapefile in Trimbles pathfinder software, but when I load vector data point shapefile that represent positions, they are off the map.
My map is in WGS 84 CRS; other shapefiles are ok, but these positions are wrong. Any help?
Here are the screenshots
0.0009° is 3.24 arc sec, which is 3.24 * cos(40°) * 101 ft/asec = 251 feet, where I’m assuming your latitude is ~40° (northern Nevada). This suggests that the transformation by the CoordTrans software is not including any datum shift of any kind.
I don’t the know the details of how you are interfacing the Trimble to the CoordTrans software, but perhaps the Trimble is set to do its own conversion to NAD27 coordinates for your benefit, producing the 0.0009° shift, and that is also being fed to CoordTrans which recognizes the shift has already been done and simply translates lat-long to feet.
Since the newer Pathfinder software is providing a correct transformation, this suggests that it’s looking at the underlying WGS84 coordinates of the Trimble and doing the transformation to NAD27 on that basis.
In summary, perhaps in actuality the Trimble is displaying and CoordTrans is seeing NAD27 data, while Pathfinder sees WGS84 data.
There is an issue regarding OpenLayers plugin in QGIS. Try to use QuickMapServices Plugin instead. Since you have the data in Excel format, save it as CSV file and load the data using Add Delimited Text Layer in QGIS as follows:
By default, it will use WGS 84 geographic spatial reference since your data is geographic.
Save the data as shapefile with WGS 84 / Pseudo Mercator (EPSG:3857) because you will use it with QuickMapServices Plugin Plugin which uses the same projection.
Load the shapefile point data created above with QuickMapServices Plugin and it should work properly.
Here is the output using a sample from your data with the correct location around Salinas:
Best Answer
I see in your screenshots that QGIS show coordinates in Gaus Kruger 7 zone for Serbia (7 500 000, 4 900 000) and that is probably from your orthophoto background map. But you are trying to open shapefile which has WGS84 coordinates.
Turn on OTF (on-the-fly) CRS transformation in your project properties:
If you have proper transformation parameters for GK7 Serbian coordinate system it should be OK. If your Trimble station is adjusted to show Gaus Kruger coordinates on the display then take those parameters from Trimble device.