Abstract—
Accuracy of range measurements using navigation satellites primarily depends on on-board clock correction parameters which are broadcasted to users periodically. The on-board clock offset, a critical correction parameter which accumulates due to fractional frequency offset as well as frequency drift, has to be maintained within the allocated broadcast limit throughout the satellite’s service. In IRNSS satellites, the clock offset is maintained within the broadcast limit by applying frequency offset corrections to the on-board atomic clock monitoring unit. In this paper, we discuss the methodology implemented for computing the clock offset using one-way range measurement data. Further, we report the time keeping methodology employed in IRNSS satellites that enables maintaining the satellite clock offset within the broadcast limit with minimum number of intervening frequency offset corrections throughout their operational life time.
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ACKNOWLEDGMENTS
The authors would like to acknowledge all the members of Space Navigation Group, U.R. Rao Satellite Centre, Bangalore for their motivation and help in carrying out the work discussed in this paper. This work is supported and funded by Indian Space Research Organisation (ISRO), India.
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Rajaiah, K., Manamohan, K., Nirmala, S. et al. Satellite Time Keeping Methodology for IRNSS/NavIC Constellation. Gyroscopy Navig. 13, 149–154 (2022). https://doi.org/10.1134/S2075108722030075
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DOI: https://doi.org/10.1134/S2075108722030075