Estimation Method for Nanosatellite Orbital Parameters in Case of Abnormal Operation of Navigation Equipment

This work suggests and investigates method that allows to estimate orbital parameters of the nanosatellite in case of abnormal operation of the on-board navigation equipment. Abnormal operation means the possibility to receive signals from not more than two navigation spacecraft. Abnormal operation of the on-board navigation equipment may be due to the performance degradation of the antenna-feeder system and amplifiers, damage of the navigation equipment during launch, and other reasons leading to the change of the antenna pattern, which prevents from receiving of all accessible signals from the navigation spacecraft.