OPTIMIZATION OF A MOBILE PSEUDOLITE TRACK FOR INCREASING ACCURACY OF THE GLONASS INTEGRATED NAVIGATION-AND-TIME FIELD
The authors study accuracy characteristics (dilution of preсision) of an integrated navigation-and-time field created by GLONASS in the terminal area with its mobile pseudolite augmentation. The research peculiarity is in placing a mobile pseudolite onboard an unmanned aerial vehicle. To achieve the best positioning accuracy in the integrated navigation-time field, it is proposed to solve the problem of optimizing the flight path of an unmanned aerial vehicle. The problem of finding the optimal track for the mobile pseudolite was solved using Hooke-Jeeves method for an aircraft approaching along a flexible track. The authors consider peculiarities of optimization problem solution using the DOP (position, horizontal, vertical) minima as optimization criteria. The values of DOP obtained experimentally for the use of stationary and mobile pseudolite are presented. Gain from the DOP value reduction caused by the use of a mobile pseudolite moving along an optimal track was evaluated. It was shown how the ratio of the approaching aircraft and pseudolite heights influenced the result of solving the problem of finding its optimal track. The influence of shadowing the signals from navigation satellites on finding the optimal track for a mobile pseudolite was estimated. Practical recommendations on the choice of optimization criteria are given, and the conditions for using a mobile pseudolite placed on board an unmanned aerial vehicle are determined.