Error in ellipsoid correction (geolocation grid) with polar stereographic map projection


I am working with a couple of S-1 scenes:


My processing chain is as follows:

Slice Assembly
Apply Orbit File
Ellipsoid Correction - GG

At the EC-GG dialog I select “NEAREST_NEIGHBOUR” as the resampling method, and select “Polar Stereographic (variant B)” as the map projection with “Standard Parallel 1” set to -71.0 - all other parameters remain at their default value.

The result looks like …

There is an obvious distortion at a point along both of the long edges that continues through the image between these two points. This is clearly seen in the following close-up …

The uncorrected image appears ok …

Not really sure how such a distortion would arise. Same things happens if I choose the “Polar Stereographic” map projection.

If I do “Ellipsoid Correction - RD” instead (with the same Polar Stereographic map projection settings), the resulting image is ok.