A spatiotemporal analysis of the effect of ambient temperatures on the thermal behaviour of the Lunar Laser Ranging optical telescope at Hartebeesthoek Radio Astronomy Observatory

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dc.contributor.author Tsela, Philemon Lehlohonolo
dc.contributor.author Combrinck, Ludwig
dc.contributor.author Ngcobo, B.
dc.date.accessioned 2017-05-10T07:42:33Z
dc.date.available 2017-05-10T07:42:33Z
dc.date.issued 2016-11
dc.description.abstract Development of the 1-meter aperture Lunar Laser Ranging (LLR) telescope is underway at the Hartebeesthoek Radio Astronomy Observatory (HartRAO) which is expected to achieve sub-centimeter range precision and accuracy to the Moon, for enhanced tests of Earth-Moon system dynamics. Key to the operational performance of the telescope is thermal analysis of the telescope composite structure including the optical mirrors. This study presents a thermal analysis on the integrated component materials comprising the LLR telescope in ANSYS, with the aim of simulating its thermal behaviour in response to site-based ambient air temperature (TA). Results show that for a full day TA profile spanning the time period 00:00 to 23:59 the resulting range of simulated thermal variations measured at 12:00 midday and 23:59 nighttime across the telescope composite structure was found to be 9.11 ºC to 10.03 ºC and 9.12 ºC to 9.86 ºC respectively. In particular, the spider assembly and outer tube surface had the largest range of thermal variations i.e. greater than absolute 1 ºC and thus, could be the main areas on the telescope where most thermal variations would occur. Furthermore, validation of the outer tube thermal variations using the 64 Resistant Temperature Detector (RTD) sensors mounted onto the test tube, showed relatable overall thermal variations of about 2 ºC, at wind speeds of 0 to 0.4 km/h. In overall, these findings provide a typical expectation of the LLR telescope thermal behavior in response to TA at the site; and thus could be used as a guide to develop an RTD-based thermal monitoring system for the HartRAO LLR optical telescope. en_ZA
dc.description.department Geography, Geoinformatics and Meteorology en_ZA
dc.description.librarian am2017 en_ZA
dc.description.sponsorship The National Research Foundation of South Africa en_ZA
dc.description.uri http://www.sajg.org.za/index.php/sajg en_ZA
dc.identifier.citation Tsela, PL, Combrinck, L & Ngcobo, BL 2016, 'A spatiotemporal analysis of the effect of ambient temperatures on the thermal behaviour of the Lunar Laser Ranging optical telescope at Hartebeesthoek Radio Astronomy Observatory', South African Journal of Geomatics, vol. 5, no. 3, pp. 373-392. en_ZA
dc.identifier.issn 2225-8531
dc.identifier.other 10.4314/sajg.v5i3.8
dc.identifier.uri http://hdl.handle.net/2263/60311
dc.language.iso en en_ZA
dc.publisher CONSAS Conference en_ZA
dc.rights CONSAS Conference en_ZA
dc.subject Lunar laser ranging (LLR) en_ZA
dc.subject Hartebeesthoek Radio Astronomy Observatory (HartRAO) en_ZA
dc.subject Thermal analysis en_ZA
dc.subject Integrated component material en_ZA
dc.subject Thermal behaviour en_ZA
dc.subject Site-based ambient air temperature en_ZA
dc.subject Air temperature (TA) en_ZA
dc.title A spatiotemporal analysis of the effect of ambient temperatures on the thermal behaviour of the Lunar Laser Ranging optical telescope at Hartebeesthoek Radio Astronomy Observatory en_ZA
dc.type Article en_ZA


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