초록 ▼

In a dead reckoning navigation system a correlation scheme that operates in the frequency domain (using a discrete cosine transform (DCT) function) is implemented separately from the navigation system to determine a two-dimensional position error estimate. In this separate processing system measured

In a dead reckoning navigation system a correlation scheme that operates in the frequency domain (using a discrete cosine transform (DCT) function) is implemented separately from the navigation system to determine a two-dimensional position error estimate. In this separate processing system measured terrain data is correlated (in the frequency domain) with reference elevation stored in map format (as by way of a digital map generator (DMG)). The results of this correlation are then employed to enhance the independently operated dead reckoning navigation system so that an accurate determination of geographic position may be obtained.

대표청구항 ▼

For use with a vehicle guidance system in which geographic position data is supplied from a navigation system, an arrangement for providing said navigation system with error estimates in geographic position data supplied thereby comprising: first means for generating first signals representative of

For use with a vehicle guidance system in which geographic position data is supplied from a navigation system, an arrangement for providing said navigation system with error estimates in geographic position data supplied thereby comprising: first means for generating first signals representative of a discrete cosine transform function based upon the measured elevation of the terrain at the geographic position of the vehicle; and second means for correlating, in the discrete cosine transform domain, the first signals generated by said first means with a set of second signals representative of respective discrete cosine transform functions based upon data representative of the elevations of a plurality of geographic positions disposed about the geographic position of said vehicle as identified by data supplied from said navigation system, and producing, from said correlation of said first and second signals, third signals representative of the error estimates of position data supplied by said navigation system corresponding to said identified geographic position, a selected one of said third signals being coupled to said navigation system for updating the information processed thereby for the guidance of said vehicle.