P. A. Tupikov

The correlation-extremal navigation systems have a number of features, such as autonomy, hiding and reliability. The information about different geophysics fields can used as landmarks for aircrafts. The aircrafts obtain this information using different sensors. Coordinate calculation requires measured and stored landmark data comparison. The data from course-elevation sensors is used in received landmarks data forming. These sensors have a zero drift independently to sensors type. The zero drifts increases in time and leads to the systematic error in calculated coordinates. This error can-t be corrected using nor long time accumulation neither trace interpolation. Coordinates calculation algorithm allows computing and estimating coordinates systematic errors, caused by zero drifts. The basic proposal is to compute zero drifts of sensors and correct incoming sensors data. This correction decreases zero drift effects and decreases coordinates systematic errors. The correction coefficients can be calculated only if navigation system uses at least 3 landmarks simultaneously and these landmarks are non inline. This paper describes zero drift calculation method, based on some approximations. The correct result can be achieved only if sensors data systematic error is less than value of these sensors data. The more relative error of this parameter, the less corrected coordinates accuracy can be achieved.