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SUMMARY:Optical configuration and optical tests of the HartRAO Lunar Laser
  Ranger
DTSTART;VALUE=DATE-TIME:20140930T100000Z
DTEND;VALUE=DATE-TIME:20140930T101500Z
DTSTAMP;VALUE=DATE-TIME:20261006T154426Z
UID:indico-contribution-3951@events.saip.org.za
DESCRIPTION:Speakers: Nokwazi Purity Nkosi (Hartebeesthoek Radio Astronomy
  Observatory:Space Geodesy)\nThe Hartebeesthoek Radio Astronomy Observator
 y\, in collaboration with the Observatoire de la Côte d’Azur (OCA) and 
 NASA are developing a dual Satellite/Lunar Laser Ranging system in South A
 frica. This project will strengthen the International Laser Ranging Servic
 e network and limit the biases caused by the under representation of satel
 lite and lunar laser ranging in the Southern Hemisphere. The new system wi
 ll be designed and developed as a permanent lunar laser ranging system wit
 h high precision laser and electronic equipment to achieve millimetre accu
 racy. The telescope used is a 1-m Classical Cassegrain donated by OCA. Lim
 ited technical details of the telescope exist so tests need to be conducte
 d to determine the optical characteristics and performance of the telescop
 e. Optical testing will determine parameters such as the reflectivity\, fo
 cal lengths\, radii of curvature\, aberrations in the mirrors and the over
 all quality of the optical system. The primary mirror and its support stru
 cture will both be analysed by finite element analysis software to determi
 ne gravitational distortion. Taking into account the mirror weight\, thick
 ness and glass type\, we can determine the deformation error of the mirror
 s and see how that affects the image quality of the telescope. Based on th
 e RMS wavefront variation over the optical surface\, estimation can be mad
 e on how good the mirror was figured. The accuracy of the technique will b
 e verified once the optical quality of the system has been established thr
 ough a star test. A mirror of high quality should yield a surface accuracy
  of approximately 25 nm rms. A coudé path will be created by directing a 
 laser beam into and through the telescope via a connecting tube and a set 
 of reflective mirrors. A high quality mirror will mean minimal loss of lig
 ht in each reflection through the coudé optical path. We report on progre
 ss to date and describe the tests conducted and instruments built.\n\nhttp
 s://events.saip.org.za/event/40/contributions/3951/
LOCATION:Matjiesfontein's Lord Milner Hotel Conference Room\, Matjiesfonte
 in Station
URL:https://events.saip.org.za/event/40/contributions/3951/
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