Inter‐Calibration Between the Electron Flux Measurements of FengYun‐3B and Van Allen Probe‐A Based on Electron Phase Space Density Conjunctions

• Published in: Journal of geophysical research. Space physics 2022-09, Vol.127 (9), p.n/a
• Main Authors: Zhu, Changbo, Zhang, Xianguo, Zhang, Hui, Li, Xingji, Zong, Weiguo, Li, Jiawei, Huang, Cong, Zhang, Chenxuan, Xiang, Zheng, Chang, Zheng, Wang, Chunqin, Zhang, Shenyi, Sun, Yueqiang, Zhang, Xiaoxin
• Format: Article
• Language: English
• Subjects: Calibration; conjunction; Earth orbits; Eccentric orbits; Electron flux; Electron flux measurements; Energetic particles; Environment models; Extraterrestrial radiation; FY‐3B; Geomagnetic storms; Geomagnetism; High energy electrons; Low earth orbits; Magnetic fields; Magnetic storms; Mathematical analysis; phase space density; Pitch (inclination); Radiation; radiation belt; Radiation belts; Satellites; Space density; VAP
• ISSN: 2169-9380; 2169-9402
• DOI: 10.1029/2022JA030463

Cross‐satellite calibration of energetic particle fluxes is essential to understanding Earth's radiation belt dynamics and modeling the space radiation environment. Using the method of comparing phase space density (PSD) conjunctions in the same set of phase space coordinates, we perform a cross‐satellite calibration of energetic electron fluxes measured by the Low Earth Orbit Chinese FengYun‐3B satellite (FY‐3B) and the near‐equatorial Highly Eccentric Orbit Van Allen Probe‐A (VAP‐A), respectively. VAP‐A provides pitch angle resolved electron (directional) differential fluxes while FY‐3B provides omnidirectional electron differential fluxes. Before calculating the PSDs from FY‐3B high energy electron detector (HEED), a method is introduced to estimate the local pitch angle of FY‐3B based on the installation direction information of HEED and the T89c magnetic field model. We calculate the calibration factors by using the PSD conjunctions inferred from the two satellites for three fixed sets of (μ, K, L*) during the geomagnetic storm times. The calibration factors range from 0.76 to 0.86 varying with fixed sets of (μ, K, L*), which indicates that the electron differential fluxes from FY‐3B are higher than that from VAP‐A. During geomagnetic quiet times, we perform calibration by using independent Gaussian fitting analysis of the number of points with the unaveraged PSDs of FY‐3B and VAP‐A for three fixed sets of (μ, K, L*), with the corresponding calibration factors of 0.78, 0.72, and 0.46. The calibrated electron differential fluxes of FY‐3B measured at the high magnetic latitudes, can be used in the future modeling of the radiation belt electron dynamics. Key Points Cross‐satellite calibrations of electron fluxes measured by FengYun‐3B satellite and Van Allen Probe‐A are conducted using electron phase space densities (PSDs) We compare PSD conjunctions and perform independent Gaussian fitting analysis in the fixed sets of (μ, K, L*) The cross‐satellite calibration factors are 0.76–0.86 and 0.46–0.78 during geomagnetic storm times and quiet times, respectively