The velocity information of spacecraft can be directly obtained by the autonomous navigation method based on astronomical spectral velocity measurement. It provides complete direct velocity measurement information for...The velocity information of spacecraft can be directly obtained by the autonomous navigation method based on astronomical spectral velocity measurement. It provides complete direct velocity measurement information for the traditional navigation methods represented by astronomical angle measurement and astronomical ranging, which is of great significance for spacecraft high precision autonomous navigation. This paper comprehensively introduces the principle and navigation method of astronomical spectral velocity measurement, as well as the technical realization of the solar atomic frequency discriminator for autonomous navigation(SAFDAN) based on atomic frequency discrimination velocity measurement. The new SAFDAN is the first instrument to measure the Doppler velocity of spacecraft relative to the Sun. Carried by the CHASE mission, the in-orbit experiment of the SAFDAN is realized, and the in-orbit velocity measurement accuracy reaches 1.93 m/s, which effectively verifies the feasibility of the astronomical spectral velocity measurement method and technology.展开更多
Sporadic sodium layers(SSLs)were studied with sodium(Na)lidar at Beijing(40.5°N,116.0°E)and Haikou(19.5°N,109.1°E)in China.The altitude distribution,strength factors,and occurrence time of SSL and ...Sporadic sodium layers(SSLs)were studied with sodium(Na)lidar at Beijing(40.5°N,116.0°E)and Haikou(19.5°N,109.1°E)in China.The altitude distribution,strength factors,and occurrence time of SSL and sporadic E(Es)layer events were statistically analyzed at both observing sites.SSL occurrence had a maximum near22:00 local time,and Eslayer occurrence had a maximum before midnight.The altitude distributions of SSL and Es layer events were better correlated at Haikou than at Beijing.All the average values of height and strength factor for SSL and Eslayer events,as well as the average of the maximum frequency that can be reflected by the Eslayer(foEs),at Beijing were higher than those at Haikou.A better correlation between SSL and Eslayer events was also found at Haikou,and the formation of SSLs was considered to likely depend on the seasonal variability of chemical and dynamical processes.展开更多
基金supported by China National Space Administration(CNSA)。
文摘The velocity information of spacecraft can be directly obtained by the autonomous navigation method based on astronomical spectral velocity measurement. It provides complete direct velocity measurement information for the traditional navigation methods represented by astronomical angle measurement and astronomical ranging, which is of great significance for spacecraft high precision autonomous navigation. This paper comprehensively introduces the principle and navigation method of astronomical spectral velocity measurement, as well as the technical realization of the solar atomic frequency discriminator for autonomous navigation(SAFDAN) based on atomic frequency discrimination velocity measurement. The new SAFDAN is the first instrument to measure the Doppler velocity of spacecraft relative to the Sun. Carried by the CHASE mission, the in-orbit experiment of the SAFDAN is realized, and the in-orbit velocity measurement accuracy reaches 1.93 m/s, which effectively verifies the feasibility of the astronomical spectral velocity measurement method and technology.
基金supported by the National Natural Science Foundation of China (41264006,40905012 and 41174129)the Specialized Research Fund for State Key Laboratories of Chinathe data from the Chinese Meridian Project
文摘Sporadic sodium layers(SSLs)were studied with sodium(Na)lidar at Beijing(40.5°N,116.0°E)and Haikou(19.5°N,109.1°E)in China.The altitude distribution,strength factors,and occurrence time of SSL and sporadic E(Es)layer events were statistically analyzed at both observing sites.SSL occurrence had a maximum near22:00 local time,and Eslayer occurrence had a maximum before midnight.The altitude distributions of SSL and Es layer events were better correlated at Haikou than at Beijing.All the average values of height and strength factor for SSL and Eslayer events,as well as the average of the maximum frequency that can be reflected by the Eslayer(foEs),at Beijing were higher than those at Haikou.A better correlation between SSL and Eslayer events was also found at Haikou,and the formation of SSLs was considered to likely depend on the seasonal variability of chemical and dynamical processes.
