The Daocheng site is one of the three candidate sites for the Large Optical/infrared Telescope(LOT)of China.It was discovered by Yunnan Observatories during the survey of potential sites for the next-generation large-...The Daocheng site is one of the three candidate sites for the Large Optical/infrared Telescope(LOT)of China.It was discovered by Yunnan Observatories during the survey of potential sites for the next-generation large-aperture solar telescopes of China.This paper describes the overview of the site,the observation platform and the monitor instrument.In addition,simple statistical results are presented(from November,2016 up to December,2017).Detailed data results can refer to the overview of LOT site testing and data analysis articles,which were published during the same period.展开更多
The volume FeO and TiO_2 abundances(FTAs) of lunar regolith can be more important for understanding the geological evolution of the Moon compared to the optical and gamma-ray results. In this paper, the volume FTAs ar...The volume FeO and TiO_2 abundances(FTAs) of lunar regolith can be more important for understanding the geological evolution of the Moon compared to the optical and gamma-ray results. In this paper, the volume FTAs are retrieved with microwave sounder(CELMS) data from the Chang'E-2 satellite using the back propagation neural network(BPNN) method. Firstly, a three-layered BPNN network with five-dimensional input is constructed by taking nonlinearity into account. Then, the brightness temperature(TB) and surface slope are set as the inputs and the volume FTAs are set as the outputs of the BPNN network.Thereafter, the BPNN network is trained with the corresponding parameters collected from Apollo, Luna,and Surveyor missions. Finally, the volume FTAs are retrieved with the trained BPNN network using the four-channel TBderived from the CELMS data and the surface slope estimated from Lunar Orbiter Laser Altimeter(LOLA) data. The rationality of the retrieved FTAs is verified by comparing with the Clementine UV-VIS results and Lunar Prospector(LP) GRS results. The retrieved volume FTAs enable us to re-evaluate the geological features of the lunar surface. Several important results are as follows. Firstly, very-low-Ti(<1.5 wt.%) basalts are the most spatially abundant, and the surfaces with TiO_2> 5 wt.% constitute less than 10% of the maria. Also, two linear relationships occur between the FeO abundance(FA) and the TiO_2 abundance before and after the threshold, 16 wt.% for FA. Secondly, a new perspective on mare volcanism is derived with the volume FTAs in several important mare basins, although this conclusion should be verified with more sources of data. Thirdly, FTAs in the lunar regolith change with depth to the uppermost surface,and the change is complex over the lunar surface. Finally, the distribution of volume FTAs hints that the highlands crust is probably homogeneous, at least in terms of the microwave thermophysical parameters.展开更多
基金Fund for Astronomical Telescopes and Facility Instrumentsbudgeted from the Ministry of Finance of China(MOF)and administrated by the Chinese Academy of Sciences(CAS)+3 种基金supported by the National Natural Science Foundation of China(Grant Nos.11873092,11533009 and 11503084)the Science and Technology Development FundMacao SAR(File No.0002/2019/APD)the One Belt and One Road project of the West Light Foundation,Chinese Academy of Sciences。
文摘The Daocheng site is one of the three candidate sites for the Large Optical/infrared Telescope(LOT)of China.It was discovered by Yunnan Observatories during the survey of potential sites for the next-generation large-aperture solar telescopes of China.This paper describes the overview of the site,the observation platform and the monitor instrument.In addition,simple statistical results are presented(from November,2016 up to December,2017).Detailed data results can refer to the overview of LOT site testing and data analysis articles,which were published during the same period.
基金supported in part by the Key Research Program of the Chinese Academy of Sciences under Grant (XDPB11)in part by opening fund of State Key Laboratory of Lunar and Planetary Sciences (Macao University of Science and Technology) (Macao FDCT Grant No. 119/2017/A3)+1 种基金in part by the National Natural Science Foundation of China (Grant Nos. 41490633, 41371332 and 41802246)in part by the Science and Technology Development Fund of Macao (Grant 0012/2018/A1)
文摘The volume FeO and TiO_2 abundances(FTAs) of lunar regolith can be more important for understanding the geological evolution of the Moon compared to the optical and gamma-ray results. In this paper, the volume FTAs are retrieved with microwave sounder(CELMS) data from the Chang'E-2 satellite using the back propagation neural network(BPNN) method. Firstly, a three-layered BPNN network with five-dimensional input is constructed by taking nonlinearity into account. Then, the brightness temperature(TB) and surface slope are set as the inputs and the volume FTAs are set as the outputs of the BPNN network.Thereafter, the BPNN network is trained with the corresponding parameters collected from Apollo, Luna,and Surveyor missions. Finally, the volume FTAs are retrieved with the trained BPNN network using the four-channel TBderived from the CELMS data and the surface slope estimated from Lunar Orbiter Laser Altimeter(LOLA) data. The rationality of the retrieved FTAs is verified by comparing with the Clementine UV-VIS results and Lunar Prospector(LP) GRS results. The retrieved volume FTAs enable us to re-evaluate the geological features of the lunar surface. Several important results are as follows. Firstly, very-low-Ti(<1.5 wt.%) basalts are the most spatially abundant, and the surfaces with TiO_2> 5 wt.% constitute less than 10% of the maria. Also, two linear relationships occur between the FeO abundance(FA) and the TiO_2 abundance before and after the threshold, 16 wt.% for FA. Secondly, a new perspective on mare volcanism is derived with the volume FTAs in several important mare basins, although this conclusion should be verified with more sources of data. Thirdly, FTAs in the lunar regolith change with depth to the uppermost surface,and the change is complex over the lunar surface. Finally, the distribution of volume FTAs hints that the highlands crust is probably homogeneous, at least in terms of the microwave thermophysical parameters.