Patent ID: 7869951
Filing Date: 2011-01-11
Classification: G01S

Abstract:
1. An electromagnetic sensor system comprising a memory unit, wherein the memory unit being encoded with a computer program code such that when the computer program code is executed by the electromagnetic sensor system, the system performs a method for determining local electromagnetic sensor refractivity for a geographical position on a given date, the method comprising: providing a refractivity database containing a plurality of data points in the memory unit, each data point representing temporal averaged refractivity values at various locations around the globe; defining a grid of triangles wherein each of the data points form a vertex of said triangles; identifying the vertices of a triangle in the grid that encloses said geographical position; interpolating the temporal average refractivity value at the vertices of said triangle enclosing said geographical position to said given date; and interpolating the local refractivity at said geographical position within the triangle using Barycentric coordinates of the geographical position.