On-orbit Cross-calibration And Assimilation For Energetic Electron Observations From FengYun4A And GOES-13

The Earth radiation belt gathers a large number of energetic particle from galactic cosmic rays,solar cosmic rays and the earth radiation belt whose energy is larger than several hundred KeV^[1].These main effects include:firstly,these energetic charged particles incident into the material,charge and discharge reactions occur on the surface or inside of the material,leading to the failure of the material interior due to electromagnetic interference;secondly,the single event effect occurring by a single particle,the particle will generate a large number of electron-hole pairs through ionization,forming current pulses,and changing.The charge distribution inside the variable components causes the logical state of the components to be confused and even to fail.Thirdly,the radiation effect of high-energy charged particles will lead to the deterioration of the material and component properties of spacecraft through ionization until they fail.At the same time,the radiation effect will also cause radiation damage to the human body,seriously affecting the safety of astronauts.^[14].Since the characteristics and physical mechanism of this space particle are still unclear,magnetospheric energetic electrons have always been an important object of space environment exploration and space science research.For the purposes of studying the physical mechanisms and developing models relating to magnetospheric energetic electrons,it is necessary to use the observations from different satellites and detectors at the same time.Eliminating the systematic deviation between different detection systems to assimilate observations from different sources is essentially required by such researches.In this work,the on-orbit cross-calibration and assimilation for energetic electron observations from FengYun 4A and GOES-13 are performed.In this work,only the observations obtained under very quiet geomagnetic conditions?|Dst|<50,Kp<2?are adopted to ensure that the objects of study are the radiation belt particles,which are stably captured by the geomagnetic field.According to the physical characteristics of the radiation belt particles,that is,the three adiabatic invariants,based on the Liouville theorem,the phase space density of the stably captured particles is unchanged.In this paper,the particles energy is the same,then?is the same,and the particles direction is the same,then J is the same,then the Liouville theorem can be simplified as the drift shell₈)is the same,the fluxes is the same,and the electron fluxes observed by the two satellites are compared in the drift shell₈)coordinate.The systematic deviation between the two satellites energetic electron observations can be obtained.According to this result,data assimilation is carried out,and the results show that the system deviation can be removed well.By this research work,the systematic deviation between two important energetic electron detection systems in geosynchronous orbit is obtained.Basing on the obtained systematic deviations,the assimilations for observations from the two detection systems are achieved.This work lays a solid foundation for the follow-up theoretical and applied researches,and also provides methods for on-orbit cross-calibration and observation assimilation which could be referred to when other electronic observations on geosynchronous orbit are dealt with.