SALT segmented primary mirror: inductive edge sensors

Hitesh Gajjar; John Menzies; David Buckley; Christian Neel; Philippe Parbaud; Stéphane Royet

doi:10.1117/12.2056217

22 July 2014 SALT segmented primary mirror: inductive edge sensors

Hitesh Gajjar, John Menzies, David Buckley, Christian Neel, Philippe Parbaud, Stéphane Royet

Proceedings Volume 9145, Ground-based and Airborne Telescopes V; 91454X (2014) https://doi.org/10.1117/12.2056217
Event: SPIE Astronomical Telescopes + Instrumentation, 2014, Montréal, Quebec, Canada

Abstract

The development of an inductive edge sensor is in process for the control of the Southern African Large Telescope’s (SALT)1 segmented mirror primary. The original capacitive edge sensing system was not capable of maintaining the figure of the primary mirror due to excessive noise and a severe sensitivity to humidity despite exhaustive attempts at characterisation1. The prototype of the inductive edge sensor has progressed to a mature industrialised version that is in the process of being installed and commissioned on SALT. The performance of the sensor in response to temperature and RH is very good with a maximum error of 10nm typical after temperature compensation. The noise and control characteristics of the array have been simulated in order to establish the maximum cumulative error and error rate tolerable for the SALT specific case. It has been established through simulation that over the expected 5 day alignment cycle, a maximum cumulative error of 30nm can be tolerated.

Citation Download Citation

Hitesh Gajjar, John Menzies, David Buckley, Christian Neel, Philippe Parbaud, and Stéphane Royet "SALT segmented primary mirror: inductive edge sensors", Proc. SPIE 9145, Ground-based and Airborne Telescopes V, 91454X (22 July 2014); https://doi.org/10.1117/12.2056217

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available