Adjacency effect correction

Hello everyone,
The default adjacency range is 1km (I could not change it by the way). But, is this a 1km x 1km filter to 2km by 2km filter? I am asking because the documentation states “However, except for special landscapes the average reflectance over a large adjacency box (2 R x 2 R) usually does not change much as a function of range, because field patterns are repeated, so a range-independent weighting is recommended as it reduces the processing time”.

It seems to me it is 2km x 2km when I compare to other correction algorithms.

Thank you in advance,