An on-orbit cross-calibration between the relativistic electron observations from BeiDou M04 and GPS ns63

Abstract

Understanding the radiation belts comprehensively has prominent significance both for aerospace engineering and space weather. For both the development of radiation belts models and the research into the dynamics of energetic electrons in the inner magnetosphere, the availability of global, well cross-calibrated data is crucial. In this report, we carry out an on-orbit cross-calibration between the observations from the High Energy Electron Detector (HEED) on Bei Dou navigation satellite system (BD) of China and Combined X-ray and Dosimeter (CXD) on Global Positioning System (GPS) constellation using the relativistic electron flux data from 2012 to 2014 and obtain the systematic offsets between the two systems. The fitting results show that there is a good consistency with the electron observations from M04 and ns63 with linear fitting slopes between relativistic electron fluxes from HEED and CXD all near 0.9. Using the cross-calibration results, the observations of greater than 1 MeV electrons of M04-HEED and GPS-CXD are assimilated well by removing the system deviation. Taking advantage of assimilated electron observations from M04 and ns63, the evolution of electron energy spectrums during the two sequential magnetic storms in March 2013 is investigated. Different dynamic properties presented by assimilated observations suggest different physical process dominant during these storms. Furthermore, this case study demonstrates the significance of the cross-calibration between M04 and ns64 observations and the usefulness of assimilated observations. This work is the first try to show that the relativistic electron observation from BD is compared with the same type operational satellite GPS. It could be expected that huge assimilated observations using the cross-calibration presented in this work would be extremely useful for statistical radiation belt modeling research, space weather nowcasting and forecasting, and comprehensive scientific understanding of energetic electron dynamic processes in the radiation belts.