Subjects: Geosciences >> Space Physics submitted time 2017-01-22
Abstract： Based on the 2755 days’ (2001-05-15~2008-12-31) density data derived from CHAMP accelerometer, the model errors of JB2008 and MSISE-00 are analyzed. It is found that the two modes both overestimate the atmospheric density, but the JB2008 is better than the MSISE-00, their average bias is 2.2% and 17.6% respectively. To brief classification of space environment, the model characteristics of latitudes and local time are analyzed in each class space environment. It is found that MSISE-00 model has better local time characteristic and JB2008 has good latitude characteristics. This study has certain significance to master model error characteristics and to improve atmospheric density model.
Peer Review Status:
Awaiting Review
Subjects: Geosciences >> Space Physics submitted time 2016-05-03
Abstract： Drag coefficient sequence C_d is obtained by solving Tiangong 1 continuous 55 days (d)GPS orbit data with different arc length. The same period solar radiation flux f_(10.7)and geomagnetic index a_p,A_p sequences are high and low frequency multi-wavelet decomposed. Statistical analysis results of the multilayer sliding correlation between space environmental parameters and decomposition of C_d show that lag correlation between the satellite drag coefficient sequence after wavelet decomposition and the corresponding level of f_(10.7),A_p sequence is good. It is also verified that the C_d prediction is feasible. Prediction residuals of Cd with different regression models and different sample lengths are analyzed. The results show that the case setting sample length of 20 days and selecting f_(10.7)regression model is best. It is also show that NRLMSIS-00 model's response in the region of 350 km (Tiangong's altitude)and low-middle latitude (Tiangong's inclination)is excessive during the ascent phase of geomagnetic activity A_p and is inadequate during decline phase. Additionally,for the low-frequency decomposition sequence NRLMSIS-00 model's response is appropriate during the ascent rising phase of f_(10.7). For the high frequency decomposition sequence,NRLMSIS-00 model 's response is small-scale inadequate during the ascent phase of f_(10.7)and is excessive during the decline phase of f_(10.7). Finally,the summary of potential use and outlook are listed; this method has an important reference value for improving the spacecraft orbit prediction accuracy.
Peer Review Status:Awaiting Review
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