Open-EO / Open-EO/openeo-python-driver

geometry_to_crs reprojection is incorrect

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Dominant language
Python
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12
Forks
8
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6d 3h
Merged PRs (30d)
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Description

The projection from geometry_to_crs differs from the reprojection we get in qgis. This is especially visible when you create polygons near the north pole, such as FeatureCollection09.json. The qgis reprojection appears to be correct because there the area remains identical, where our reprojected polygons have a larger area compared to the original (area is calculated using WGS84 ellipsoid).

For nearly all use-cases the difference is negligible but it is still worth investigating if we are using the pyproj library wrong in some way.

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Research direction

Start with geometry_to_crs in openeo_driver/util/utm.py around line 59 and reproduce the issue using tests/data/geojson/FeatureCollection09.json. Compare the pyproj reprojection with the QGIS result, focusing on the preserved area of polygons near the north pole. Done means identifying whether pyproj is used incorrectly and correcting the reprojection so the result matches the expected area.

Written by the indexing model from the issue text.

Assessment

Tech stack
python
Domain
backend
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Quiet
Clarity
Mostly clear
Newbie friendliness
48/100

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