2

Here is my question:

1- Based on a long distance segment ( approx 2000 km) drawn on Google Earth and imported as shapefile in QGIS I want to obtain a terrain profile based on "Terrain Profile" plugin.

2- The problem is that my great circle segment drawn in Google Earth is not going over the same terrain in QGIS. This can be seen clearly using the Google earth layer in QGIS:

Google Earth:

Google Earth

QGIS:

QGIS

3- The difference is approx 45 km between the 2 lines and the projection of my raster is WGS84 (EPGS:4326). I tried to change my raster projection to 900913 (Google Mercator) but this doesn't work either.

Can you please let me know if there are any way to make my very long google earth segment coincide in QGIS ?

Many thanks in advance

  • 1
    You will need to segmentize (add vertices) in the original coord system. Maybe ge allows that option? You could do it in Qgis with an appropriate choice of Gnomonic but I would need to try that. Can you tell us the start and end longlat in WGS84? – mdsumner Sep 30 '14 at 10:01
  • Hello and thanks for your answer. The coordinates right now are 40N80E 30N100E but I would like to find a solution for all lat/long. This is why I thought another projection could do the trick. The only solution I found was to "cut" my line in google earth in several segments. This way the difference between great circle and rhumb line is less (Due to shorter distance). Thanks – Kara Sep 30 '14 at 11:54
1

Instead of a gnomonic projection, you can use an azimuthal equidistant projection on one of your points as well.

See my example workflow here: great circles in QGIS and export in 3857 webmap

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.