Left panel: Basket-weaving matrix A for a small test case (2 × 100 strictly orthogonal scan lines, gridded into a map of 15 × 15 pixels). The left/right part of the matrix (columns 1 to 100/columns 101 to 200) links the offsets (100 each) associated with first/second coverage to the difference map (flattened to form the vector D). Right panel: for the same example the coordinate grid was rotated by 45°. Evidently, now different offsets contribute to a pixel compared to the left panel.