Patent ID: 6810324
Filing Date: 2004-10-26
Classification: G01C

Abstract:
A method for substituting at least one high quality position measurement with a set of upgraded low quality position measurements, said method comprising the steps of:(A1) selecting a high quality source of position measurements of said object from a group of high quality sources; (A2) obtaining at least one high quality position measurement of said object obtained by using said high quality source; (B) saving said at least one high quality position measurement of said object; (C) obtaining at least one low quality position measurement of said object using a low quality source; (D) if said at least one high quality position measurement of said object is of substantially high quality, using said at least one high quality position measurement of said object for navigation purposes of said object; (E) if each said high quality position measurement of said object is not of substantially high quality, and if each said low quality position measurement of said object is not of substantially high quality, upgrading said at least one low quality position measurement of said object by using said at least one high quality position measurement of said object to obtain at least one upgraded low quality position measurement of said object; and (F) using said at least one upgraded low quality position measurement of said object in place of said at least one high quality position measurement of said object for navigation purposes, if each said upgraded low quality position measurement of said object is of substantially high quality; wherein said at least one high quality position measurement of said object includes a high quality epoch timing coordinate indicative of when said high quality position measurement of said object was taken, and wherein said high quality position measurement of said object is of said high quality if said high quality position measurement of said object includes an acceptable error in said high quality position measurement of said object and is substantially recent, and wherein each said high quality position measurement of said object is of said high quality if said high quality position measurement of said object satisfies a threshold of acceptability requirement for said object, and wherein the threshold of acceptability is defined as a bound between said acceptable error in a position measurement of said object and an unacceptable error in said position measurement of said object, and wherein said high quality position measurement is substantially recent if a rate of updating said high quality position measurement is substantially sufficient to obtain a substantially accurate position measurement of said object.