Three‐Dimensional Gravity Model Applied to Underwater Navigation

Abstract

At present, new integrated navigation, which usesthe location function of reference gravity anomaly map to control the errors of the inertial navigation system (INS), has been developed in marine navigation. It is named the gravityaided INS. Both the INS and real-time computation of gravity anomalies need a 3-D marine normal gravity model. Conventionally, a reduction method applied in geophysical survey is directly introduced to observed data processing. This reduction does not separate anomaly from normal gravity in the observed data, so errors cannot be avoided. The 3-D marine normal gravity model was derived from the J2 gravity model, and is suitable for the region whose depth is less than lo00 m. Comparison of four gravity models. Papers to the Position Location and Navigation symposium, IEEE, 63 1-635. Hsu, D.Y., 1998. An accurate and efficient approximation to the normal gravity. Papers to the Position Location a d Navigation Symposium, IEEE, 38-44. Jircitano, A., and Dosch, D.E., 1991. Gravity aided inertid navigation system. Papers to the ION 47th Annual Meeting proceeding on Navigation and Explorarion, 22 1-229. Jircitano, A., White, J., and Doah, D., 1990. Gravity based navigation of AUVs, AW'90. Symposium on A W , 177-180. Mularie, W.M.. uw)o. Natwnal h w r y and Mapping Agtm,, Technical Report 8350.2 (third edition), 175. Rice. H., Mendehhn, L., Arons, R., and M -l a , D., 2000. Next generation marine precision navigation system. Papers to Position Location and Navigation Symposium, IEEE, 2W206. Shi Pan and Sun zhongmiao, 1999. "he solution to the problem of the spherical interior Dirichlet and its application. Acts Geodnetic et Cartographica Sinica, 28(3): 195-198 ( i n Chinese with English abstract). wei Ziqing, 2003. Normal gravity formulae. Actu Geodaetica et Cartographica Sinicu 32(2): 95-101 (in Chinese with English abstract),