THE EFFECTS OF GRAVITATIONAL UNCERTAINTIES ON THE ERRORS OF INERTIAL NAVIGATION SYSTEMS

R. R. Hildebrant, K. R. Brittiny and S. J. Madden, Jr.

Peer Reviewed

Abstract: The benefits in reduced inertial navigation errors to be gained by implementating a gradiometer to measure and compensate for the gravitational vector is studied. A limit to this improvement is obtained through a parametric study that was made to compare the magnitude of the geodetic error, due to incorrect compensation, with error due to the instruments comprising the inertial system. This was done for three levels of system accuracy; “production” systems, characteristic of equipment used today; state-of-the-art systems; and a future class of systems. It was found that geodetically induced position errors generally make up a rather small proportion of total system error, less than 30% even for the future class. However, its contribution to the velocity error is quite high, approximately 50% for production, 70% for state-of-the-art, and 94% for future systems. The error behavior of a gradiometer compensated system was then investigated. When the gradiometer uncertainties are modelled as white noise, their level of accuracy must be within 1.7 and 0.93 Eotvos units to reduce, respectively, the geodetic induced velocity and position error below that value which a system with no gradiometer already exhibits. When gradiometer uncertainties are modeled as random biases, their level of accuracy must be within approximately 1.7 and .l Eotvos units to reduce geodetic induced velocity and position error respectively.
Published in: NAVIGATION, Journal of the Institute of Navigation, Volume 21, Number 4
Pages: 357 - 363
Cite this article: Hildebrant, R. R., Brittiny, K. R., Madden, S. J., Jr.,, "THE EFFECTS OF GRAVITATIONAL UNCERTAINTIES ON THE ERRORS OF INERTIAL NAVIGATION SYSTEMS", NAVIGATION, Journal of The Institute of Navigation, Vol. 21, No. 4, Winter 1974-1975, pp. 357-363.
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