Coordinates Conversion Method Of Conservative Physical Parameters From Latitude-Longitude Coordinates System To Rotated Cubed-Sphere Coordinates System And Hardware Device Performing The Same

摘要

A method of converting coordinates of a physical quantity from a latitude-longitude coordinates system to a rotated cubed-sphere coordinates system is disclosed. The method is performed in a hardware device including a computation part and a memory. A plurality of latitude-longitude grid areas which overlap a cubed-sphere grid area is determined. An overlapping area between the cubed-sphere grid area and the latitude-longitude grid areas is computed.

主权项

1. A method of converting coordinates of a physical quantity from a latitude-longitude coordinates system to a rotated cubed-sphere coordinates system, wherein the method performed in a hardware device comprising a computation part and a memory electrically connected to the computation part, the computation part comprising a plurality of computing units, and the method comprising;
determining a plurality of latitude-longitude grid areas which overlap a cubed-sphere grid area; and computing an overlapping area between the cubed-sphere grid area and the latitude-longitude grid areas, wherein the determining the latitude-longitude grid areas which overlap the cubed-sphere grid area comprises: determining a plurality of vertex areas among the latitude-longitude grid areas, the vertex areas comprising first vertex points of the cubed-sphere grid area respectively; determining first intersection points at which a latitude grid line or a longitude grid line crosses a cubed-sphere grid line, the first intersection points being located between the vertex areas; determining a plurality of boundary latitude-longitude grid areas among the latitude-longitude grid areas, the boundary latitude-longitude grid areas being directly adjacent to each of the first intersection points; and determining a plurality of inner latitude-longitude grid areas among the latitude-longitude grid areas, the inner latitude-longitude grid areas being surrounded by the vertex areas and the boundary latitude-longitude grid areas, wherein the determining the first intersection points at which the latitude grid line or the longitude grid line crosses the cubed-sphere grid line comprises: converting first coordinates of the vertex points of the cubed-sphere grid area defined in a cubed-sphere coordinates system into second coordinates defined in a three-dimensional Cartesian coordinates system; converting the second coordinates defined in the three-dimensional Cartesian coordinates system into third coordinates defined in the latitude-longitude coordinates system; and defining a parameter by a difference between one of values of the third coordinates and a latitude value of an equi-latitude grid line or a longitude value of an equi-longitude grid line, and wherein the first intersection points are determined by points which make the parameter close to zero in a predetermined error range respectively.