JPL Technical Report Server

Laser Metrology for Ultra-Stable Space-Based Coronographs

Show simple item record Nissen, Joel A. Azizi, Alireza Zhao, Feng Zareh, Shannon Kian G. Rao, Shanti R. Jewell, Jeffrey B. Moore, Dustin 2020-05-07T00:58:58Z 2020-05-07T00:58:58Z 2018-08-19
dc.identifier.citation SPIE Optical Engineering + Applications, San Diego, CA, August 19 - 23, 2018 en_US
dc.identifier.clearanceno 18-2434
dc.description.abstract Sensing starlight rejected from a coronagraph is essential in stabilizing the telescope pointing and wavefront drift, but performance is degraded for dim stars. Laser Metrology (MET) provides a different, complementary sensing method, one that can be used to measure changes in the alignment of the optics at high bandwidth, independent of the magnitude of the host star. Laser metrology measures changes in the separation of optical fiducial pairs, which can be separated by many meters. The principle of operations is similar to the laser metrology system used in LISA-Pathfinder to measure the in-orbit displacement between two test masses to a precision of ~10 picometers. In closed loop with actuators, MET actively maintains rigid body alignment of the front-end optics, thereby eliminating the dominant source of wavefront drift. In the case of a segmented, active primary mirror, MET provides six degrees of freedom sensing, replacing edge sensors. MET maintains wavefront control even during attitude maneuvers, such as slews between target stars, thereby avoiding the need to repeat time-consuming speckle suppression. These features can significantly improve the performance and observational efficiency of future large-aperture space telescopes equipped with internal coronagraphs. We evaluate MET trusses for various proposed monolithic and segmented space-based coronagraphs and present the performance requirements necessary to maintain contrast drift below 10^-11. en_US
dc.description.sponsorship NASA/JPL en_US
dc.language.iso en_US en_US
dc.publisher Pasadena, CA: Jet Propulsion Laboratory, National Aeronautics and Space Administration, 2018 en_US
dc.subject Laser Metrology en_US
dc.subject Coronagraph en_US
dc.title Laser Metrology for Ultra-Stable Space-Based Coronographs en_US
dc.type Preprint en_US

Files in this item

This item appears in the following Collection(s)

Show simple item record



My Account