Astronomical Observatory

14,000,000 Leading Edge Experts on the ideXlab platform

Scan Science and Technology

Contact Leading Edge Experts & Companies

Scan Science and Technology

Contact Leading Edge Experts & Companies

The Experts below are selected from a list of 20622 Experts worldwide ranked by ideXlab platform

Na Wang - One of the best experts on this subject based on the ideXlab platform.

  • the xinjiang Astronomical Observatory nsrt pulsar data archive
    Advances in Astronomy, 2019
    Co-Authors: Hailong Zhang, Na Wang, Markus Demleitner, Jie Wang, Jun Nie, Jianping Yuan
    Abstract:

    The sensitivity of our pulsar observation system with typical integration time of 16 minutes has reached 0.4 mJy after we have upgraded the receiver cooling system of NanShan 25-m radio telescope (NSRT) at Xinjiang Astronomical Observatory (XAO) in 2002. About 280 pulsars were observed after the upgrade. The NanShan station pulsar data is transmitted to the data center at XAO headquarters via a 300Mb/s dedicated data link for long-term storage, and the remote backup is realized by synchronous data transmission between NanShan station and XAO headquarters. Metadata extraction, archiving, and releasing are completed by the data release servers which are located in XAO headquarters. At present, more than 84000 pulsar observation data files in the PSRFITS format have been released with a maximum file size of 1GB. XAO pulsar data online service provides cone search and multiobject constraint query. We have published our data based on Virtual Observatory (VO) standards. The online pulsar data service is registered in the International Virtual Observatory Alliance’s Registry. Users can access the data through common VO tools.

  • Pulsar Timing at Urumqi Astronomical Observatory
    International Astronomical Union Colloquium, 2016
    Co-Authors: Na Wang, Xin-ji Wu, Jin Zhang, Richard N. Manchester, Aili Yusup, K. S. Cheng
    Abstract:

    AbstractA pulsar timing system has been set up using the 25-m Nanshan telescope of the Urumqi Astronomical Observatory. It uses a dual polarization receiver operating at 18 cm and a filterbank receiver. The data acquisition system is based on a PC using the Windows NT operating system. Timing properties of about 100 pulsars will be monitored with this system.

  • pulsar timing at urumqi Astronomical Observatory observing system and results
    Monthly Notices of the Royal Astronomical Society, 2001
    Co-Authors: Na Wang, Jin Zhang, Richard N. Manchester, Aili Yusup, K. S. Cheng, A. G. Lyne, M Z Chen
    Abstract:

    A pulsar timing system has been operating in the 18-cm band at the Urumqi Astronomical Observatory 25-m telescope since mid-1999. Frequency resolution allowing de-dispersion of the pulsar signals is provided by a filterbank/digitizer system. Observations of 74 pulsars over more than 12 months have resulted in updated pulsar periods and period derivatives, as well as improved positions. Comparison with previous measurements showed that the changes in period and period derivative tend to have the same sign and to be correlated in amplitude. A model based on unseen glitches gives a good explanation of the observed changes, suggesting that long-term fluctuations in period and period derivatives are dominated by glitches. In 2000 July, we detected a glitch of relative amplitude in the Crab pulsar. The post-glitch decay appears similar to other large Crab glitches.

  • The Observation of Pulsars at Urumqi Astronomical Observatory
    Stellar Astrophysics, 2000
    Co-Authors: Na Wang, Jin Zhang, Richard N. Manchester, Aili Yusup, K. S. Cheng, Ali Esamdin, A. G. Lyne, Hong-bo Zhang, Liansen Kang
    Abstract:

    The pulsar’s observation is being developed using the 25m radio telescope at Urumqi Astronomical Observatory (UAO). A pulsar timing system has been set up. It uses a dual polarization receiver operating at 18cm and a filterbank receiver. Timing properties of about 100 pulsars will be monitored with this system. The single channel system at 92 cm works since 1996 for the program of mean pulse profile and long term variation of intensity about 18 pulsars. The observation of spectrum properties for few strong pulsars at 92cm, 18cm, 13cm, 6cm, and 3.6cm is in progress.

M Z Chen - One of the best experts on this subject based on the ideXlab platform.

  • pulsar timing at urumqi Astronomical Observatory observing system and results
    Monthly Notices of the Royal Astronomical Society, 2001
    Co-Authors: Na Wang, Jin Zhang, Richard N. Manchester, Aili Yusup, K. S. Cheng, A. G. Lyne, M Z Chen
    Abstract:

    A pulsar timing system has been operating in the 18-cm band at the Urumqi Astronomical Observatory 25-m telescope since mid-1999. Frequency resolution allowing de-dispersion of the pulsar signals is provided by a filterbank/digitizer system. Observations of 74 pulsars over more than 12 months have resulted in updated pulsar periods and period derivatives, as well as improved positions. Comparison with previous measurements showed that the changes in period and period derivative tend to have the same sign and to be correlated in amplitude. A model based on unseen glitches gives a good explanation of the observed changes, suggesting that long-term fluctuations in period and period derivatives are dominated by glitches. In 2000 July, we detected a glitch of relative amplitude in the Crab pulsar. The post-glitch decay appears similar to other large Crab glitches.

G. Theureau - One of the best experts on this subject based on the ideXlab platform.

  • RFI mitigation in the context of pulsar coherent de-dispersion at the Nancay Radio Astronomical Observatory
    2009 17th European Signal Processing Conference, 2009
    Co-Authors: Ait D. Allal, R. Weber, I. Cognard, G. Desvignes, G. Theureau
    Abstract:

    Radio Astronomical pulsar observations require specific instrumentation and dedicated signal processing to cope with the dispersion caused by the interstellar medium. Moreover, the quality of observations can be limited by radio frequency interferences (RFI) generated by Telecommunications activity. This paper will present the innovative pulsar instrumentation based on Graphical Processing Units (GPU) which has been designed at the Nançay Radio Astronomical Observatory. In addition, first simulated results on RFI cyclostationary detectors, which will be implemented on the system, will be described and discussed.

Z Eker - One of the best experts on this subject based on the ideXlab platform.

  • multi criteria decision analysis integrated with gis and remote sensing for Astronomical Observatory site selection in antalya province turkey
    Advances in Space Research, 2013
    Co-Authors: Dilek Kocsan, Bekir Taner San, V Bakis, M Helvaci, Z Eker
    Abstract:

    Abstract Astronomical Observatory site selection is a complex problem that involves evaluation of multiple factors from different sources. The aim of this study is to select the best possible candidates for Astronomical observations sites using Multi-Criteria Decision Analysis integrated with Geographical Information Systems and remote sensing technologies. The study was implemented in the Antalya province of Turkey, which is convenient for Astronomical site Observatory facilities with its appropriate climate properties and weather conditions. Eleven factors (cloud cover, precipitable water, earthquake zones, geology, landslide inventory, active fault lines, Digital Elevation Model, city lights, mining activities, settlement areas, roads) were determined, splitting into three categories; meteorological, geographical and anthropogenic criteria. These factors were evaluated using Analytical Hierarchy Process method and the weights of criteria layers were determined. As a result, the most suitable areas were located extensively in western and eastern part of Antalya. This study offers a robust, accurate, cost and time effective procedure for preliminary site selection for Astronomical Observatory. However, for a final decision of the best location of Astronomical Observatory, site testing measurements and atmospheric seeing observations will be further required in these preliminary areas.

Hong Xiao-yu - One of the best experts on this subject based on the ideXlab platform.

Related terms

Astronomical Observatory - 15 days free trial to Access Experts & Abstracts