Patent ID: 6711517
Filing Date: 2004-03-23
Classification: G01C

Abstract:
Long-duration navigation method by means of a first strapdown navigation unit generating a first state vector whose components give position, attitude and speed values of a carrier with a small instantaneous error, comprising the steps of:generating by means of a second navigation unit, a second state vector whose components give position, attitude and speed values of the said carrier with a small long-term error; combining the first and second state vectors by subtracting the second vector from the first vector to obtain an error observation vector; generating an error estimate vector from the error observation vector, by means of a filter; and combining the error estimate vector thus obtained with the first state vector by subtracting the error estimate vector from the first state vector so as to obtain an estimated vector of the carrier position, attitude and speed values with a small instantaneous error and a small long-term error.