Patent ID: 7818115
Filing Date: 2010-10-19
Classification: G01C

Abstract:
1. A process for determining, as a navigation solution of a navigation system with a Terrain Navigation Module, an individual position of an aircraft or watercraft, comprising: determining a supported aircraft or watercraft position solution, and a relative covered path between two height measurements with navigation sensors, a Strap Down Module, and a navigation filter, ascertaining a quality of each active supported aircraft or watercraft position solution from each respective active supported aircraft or watercraft position using a first quality function, creating both a search area, based on predetermined criteria and each respective supported aircraft or watercraft position solution as well as predetermined aircraft or watercraft positions inside the search area, storing an active terrain height measurement and the relative covered path between the active terrain height measurement and a last stored terrain height measurement in order to ascertain a quality of each respective covered path and a quality of each respective stored terrain height measurement, determining a relative position for each respective predetermined aircraft or watercraft position inside the search area and each respective stored covered path, determining a quality transformed via a reference map of each respective stored covered path by way of a second quality function under use of each stored covered path, ascertaining a quality of each respective stored terrain height measurement by way of a third quality function under use of a corresponding stored terrain height measurement, ascertaining a quality of each reference height for each relative position from predetermined parameters and corresponding reference heights by way of a fourth quality function, determining a distribution function of error measurement for each relative position from a function of the quality of each active supported position solution, the quality transformed via the reference map of each respective stored covered path, the quality of each respective stored terrain height measurement, and the quality of each reference height, ascertaining a distribution function of a total error for each predetermined aircraft or watercraft position inside the search area as a function of the distribution function of the error measurement, ascertaining minimum probabilities of all used aircraft or watercraft positions in the search area by way of a function of the distribution function of the total error as a probability with which each aircraft or watercraft position in the search area exhibits a minimal total error, determining a quality of a position support, to be supplied to and used in said navigation filter, as a function of all minimum probabilities, protecting the navigation solution ascertained in the Strap Down Module via the navigation filter with aid of an actual position support, to be supplied to and used, together with said quality of position support, in said navigation filter and the determined quality of the position support by closing recursion to stabilize navigation over an extended term, and outputting the navigation solution as the individual position of the aircraft or watercraft.