Paper 14145-247
Paper 14145-247
Lyot-based low-order wavefront sensor (LLOWFS) for the Habitable Worlds Observatory
8 July 2026 • 17:30 - 19:00 CEST | Room B4-M3
Abstract
The Habitable Worlds Observatory (HWO) coronagraph contrast stability required to differentiate planets from residual speckles in the dark hole and to detect planets with proper signal-to-noise ratio (SNR) drives very tight tolerances for wavefront variation. The wavefront needs to be stable within 10 pm over 10 minutes and the tip-tilt control needs to be at the sub-milliarcsecond level. Here we describe a Lyot-based low-order wavefront sensor (LLOWFS) for the Exploratory Analytic Case 1 (EAC1) design for the HWO using the scalar vortex coronagraph (SVC) to estimate dynamic low-order wavefront aberrations. The LLOWFS uses rejected starlight from the Lyot stop and slightly defocused images to infer thermally induced low-order aberrations. In this paper, we review the theory of LLOWFS operation, describe the LLOWFS algorithm, and summarize various numerical sensitivity studies on sensor performance.
Presenter
NASA Goddard Space Flight Ctr. (United States)
Hari Subedi is an optical engineer at NASA Goddard Space Flight Center in Greenbelt, Maryland. He received his bachelor's degree in aerospace engineering from the University of Arizona in 2013 and his PhD in mechanical and aerospace engineering from Princeton University in 2018. During his graduate studies, Hari was an NSF Graduate Research Fellow. His research interests include wavefront sensing and control, deformable mirrors, and instrumentation for space-based telescopes.