The KD-Tree-based nearest-neighbor search algorithm in GRID interpolation

The nearest neighbor search algorithm constitutes one of the major elements that influence the efficiency of GRID interpolation. Hence, this paper introduces the two-dimensional index structure of KD-Tree, puts forward an improved J-nearest neighbor search strategy based on “priority queue” and “neighbor lag”, designs respectively two kinds of J-nearest neighbor search algorithm in response to two search principles of fixed points number and fixed radius typical in GRID interpolation, and at length, realizes the whole interpolation process taking IDW and Kriging as two instances. As the experiment turns out, the algorithm raised in the paper has high operating efficiency-in particular when the data amount is enormous, and is of admirable practical value in promoting the efficiency of GRID interpolation.