We present seeing measurements of the Guoshoujing Telescope （formerly named the Large Sky Area Multi-Object Fiber Spectroscopic Telescope- LAMOST） site at Xinglong station during the period from 2007 March 12 to Apr...We present seeing measurements of the Guoshoujing Telescope （formerly named the Large Sky Area Multi-Object Fiber Spectroscopic Telescope- LAMOST） site at Xinglong station during the period from 2007 March 12 to April 25. The measurements were carried out with the Differential Image Motion Monitor （DIMM）, and a total of 9259 data sets was obtained. The median seeing was measured to be 1.1″, with 25% being better than 0.8″and 75% better than 1.5″. The experiment shows that the DIMM exposure time has significant effects on the results of seeing measurements. An SBIG Polaris seeing monitor, which had been planned to be installed on the LAMOST site for long-term monitoring, was also employed during the DIMM observations. The results show that the SBIG seeing monitor is easily affected by gusty wind, resulting in larger seeing values. Considering the previous seeing measurements at Xinglong station over the last 15 yr, we conclude that an acceptable seeing condition at Xinglong station is around 1″-2″.展开更多
An astronomical observatory is the core component of any astronomical research facility that connects astronomers with their lab: the Cosmos. The research quality of an astronomical facility is rooted in the precision...An astronomical observatory is the core component of any astronomical research facility that connects astronomers with their lab: the Cosmos. The research quality of an astronomical facility is rooted in the precision of data, collected by its observatory. For optimal performance, an observatory is sited while considering certain astronomical, environmental, geological and social parameters. This study aims to identify the potential sites in Pakistan for locating an optical-astronomical observatory using the Multicriteria Decision Analysis(MCDA) technique. The study uses the Analytic Hierarchy Process(AHP) for deriving the influence weights of nine evaluation criteria: Photometric Night Fraction;Night-time Sky Brightness;Sky Transparency;Aerosol Concentration;Altitude;Terrain Slope;Accessibility;Seismic Vulnerability;and Landuse/Land Cover. On the basis of experts’ opinions and previous studies, the evaluation criteria have been ordered in two possible preference sequences for identifying their influence weights with respect to each other for taking part in MCDA. Consequently, the process of MCDA identified certain areas with respect to each preference sequence, whereas some areas were found to be suitable according to both preference sequences. The study synchronizes the required eclectic data into an evaluation matrix that augments the process of astronomical site selection. In the future, this study will be useful for astronomical societies and for furthering astronomical research in the country.展开更多
Dome A,Antarctica,has been thought to be one of the best astronomical sites on the Earth for decades.Since it was first visited by astronomers in 2008,dozens of facilities for astronomical observation and site testing...Dome A,Antarctica,has been thought to be one of the best astronomical sites on the Earth for decades.Since it was first visited by astronomers in 2008,dozens of facilities for astronomical observation and site testing were deployed.Due to its special geographical location,the data and message exchange between Dome A and the domestic control center could only depend on Iridium.Because the link bandwidth of Iridium is extremely limited,the network traffic cost is quite expensive and the network is rather unstable,the commonly used data transfer tools,such as rsync and scp,are not suitable in this case.In this paper,we design and implement a data transfer tool called NBFTP(narrow bandwidth file transfer protocol)for the astronomical observation of Dome A.NBFTP uses a uniform interface to arrange all types of data and matches specific transmission schemes for different data types according to rules.Break-point resuming and extensibility functions are also implemented.Our experimental results show that NBFTP consumes 60%less network traffic than rsync when detecting the data pending to be transferred.When transferring small files of 1 KB,the network traffic consumption of NBFTP is 40%less than rsync.However,as the file size increases,the network traffic consumption of NBFTP tends to approach rsync,but it is still smaller than rsync.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.10903014 and10778709)supported by the Young Researcher Grant of National Astronomical Observatories,Chinese Academy of Sciences
文摘We present seeing measurements of the Guoshoujing Telescope （formerly named the Large Sky Area Multi-Object Fiber Spectroscopic Telescope- LAMOST） site at Xinglong station during the period from 2007 March 12 to April 25. The measurements were carried out with the Differential Image Motion Monitor （DIMM）, and a total of 9259 data sets was obtained. The median seeing was measured to be 1.1″, with 25% being better than 0.8″and 75% better than 1.5″. The experiment shows that the DIMM exposure time has significant effects on the results of seeing measurements. An SBIG Polaris seeing monitor, which had been planned to be installed on the LAMOST site for long-term monitoring, was also employed during the DIMM observations. The results show that the SBIG seeing monitor is easily affected by gusty wind, resulting in larger seeing values. Considering the previous seeing measurements at Xinglong station over the last 15 yr, we conclude that an acceptable seeing condition at Xinglong station is around 1″-2″.
文摘An astronomical observatory is the core component of any astronomical research facility that connects astronomers with their lab: the Cosmos. The research quality of an astronomical facility is rooted in the precision of data, collected by its observatory. For optimal performance, an observatory is sited while considering certain astronomical, environmental, geological and social parameters. This study aims to identify the potential sites in Pakistan for locating an optical-astronomical observatory using the Multicriteria Decision Analysis(MCDA) technique. The study uses the Analytic Hierarchy Process(AHP) for deriving the influence weights of nine evaluation criteria: Photometric Night Fraction;Night-time Sky Brightness;Sky Transparency;Aerosol Concentration;Altitude;Terrain Slope;Accessibility;Seismic Vulnerability;and Landuse/Land Cover. On the basis of experts’ opinions and previous studies, the evaluation criteria have been ordered in two possible preference sequences for identifying their influence weights with respect to each other for taking part in MCDA. Consequently, the process of MCDA identified certain areas with respect to each preference sequence, whereas some areas were found to be suitable according to both preference sequences. The study synchronizes the required eclectic data into an evaluation matrix that augments the process of astronomical site selection. In the future, this study will be useful for astronomical societies and for furthering astronomical research in the country.
基金supported by the Joint Research Fund in Astronomy(U1931130)under the cooperative agreement between the National Natural Science Foundation of China(NSFC)and the Chinese Academy of Sciences(CAS)support from NFSC(Grant Nos.11873010and 117330037)the Operation,Maintenance and Upgrading Fund for Astronomical Telescopes,and Facility Instruments,budgeted from the Ministry of Finance of China(MOF)and administrated by the CAS。
文摘Dome A,Antarctica,has been thought to be one of the best astronomical sites on the Earth for decades.Since it was first visited by astronomers in 2008,dozens of facilities for astronomical observation and site testing were deployed.Due to its special geographical location,the data and message exchange between Dome A and the domestic control center could only depend on Iridium.Because the link bandwidth of Iridium is extremely limited,the network traffic cost is quite expensive and the network is rather unstable,the commonly used data transfer tools,such as rsync and scp,are not suitable in this case.In this paper,we design and implement a data transfer tool called NBFTP(narrow bandwidth file transfer protocol)for the astronomical observation of Dome A.NBFTP uses a uniform interface to arrange all types of data and matches specific transmission schemes for different data types according to rules.Break-point resuming and extensibility functions are also implemented.Our experimental results show that NBFTP consumes 60%less network traffic than rsync when detecting the data pending to be transferred.When transferring small files of 1 KB,the network traffic consumption of NBFTP is 40%less than rsync.However,as the file size increases,the network traffic consumption of NBFTP tends to approach rsync,but it is still smaller than rsync.
