Doppler collision has a very important issue in satellite-based navigation systems. Navigation with the Indian Constellation(NavIC) comprises seven operational satellites, among which three are geo-stationary (GEO) sa...Doppler collision has a very important issue in satellite-based navigation systems. Navigation with the Indian Constellation(NavIC) comprises seven operational satellites, among which three are geo-stationary (GEO) satellites, and the rest aregeosynchronous satellites. Due to the ’small line of sight velocities’ of GEO satellites, estimated ranges suffer from theunique challenge of Doppler collision (DC). In this study, we present an analysis of DC events in both static and dynamicconditions, particularly in aerospace applications.We utilize experimental data acquired from the Indian Regional NavigationSatellite System (IRNSS)-GPS-Satellite Based Augmentation System (SBAS) (IGS) receiver located at a low altitude stationto develop algorithms for the prediction, avoidance, and mitigation of DC events. The prediction of DC is based on themovingaverage method.We have devised an efficient algorithm to avoid the occurrence of DC, considering all possible combinationsof IRNSS GEO satellites. Additionally, we perform the mitigation of DC using a proposed hybrid approach that involves boththe space segment and user segment. The approach is based on repositioning the IRNSS 1C satellite and varying the loopbandwidth of the Delay Locked Loop (DLL). With the implementation of this proposed hybrid approach, the time durationof DC is reduced by 59.16% in static conditions and 16% in dynamic conditions.展开更多
文摘Doppler collision has a very important issue in satellite-based navigation systems. Navigation with the Indian Constellation(NavIC) comprises seven operational satellites, among which three are geo-stationary (GEO) satellites, and the rest aregeosynchronous satellites. Due to the ’small line of sight velocities’ of GEO satellites, estimated ranges suffer from theunique challenge of Doppler collision (DC). In this study, we present an analysis of DC events in both static and dynamicconditions, particularly in aerospace applications.We utilize experimental data acquired from the Indian Regional NavigationSatellite System (IRNSS)-GPS-Satellite Based Augmentation System (SBAS) (IGS) receiver located at a low altitude stationto develop algorithms for the prediction, avoidance, and mitigation of DC events. The prediction of DC is based on themovingaverage method.We have devised an efficient algorithm to avoid the occurrence of DC, considering all possible combinationsof IRNSS GEO satellites. Additionally, we perform the mitigation of DC using a proposed hybrid approach that involves boththe space segment and user segment. The approach is based on repositioning the IRNSS 1C satellite and varying the loopbandwidth of the Delay Locked Loop (DLL). With the implementation of this proposed hybrid approach, the time durationof DC is reduced by 59.16% in static conditions and 16% in dynamic conditions.
