Explanipedia

Overview of the Fiber System for the Dark Energy Spectroscopic Instrument Open

Claire Poppett, Luke Tyas, J. Aguilar, C. Bebek, David G. Bramall , et al. · 2024

The Dark Energy Spectroscopic Instrument (DESI) is a revolutionary instrument designed for precise measurements of cosmic distances and the investigation of dark energy. DESI utilizes 5000 optical fibers to simultaneously measure the spect…

Overview of Space-Based Laser Communication Missions and Payloads: Insights from the Autonomous Laser Inter-Satellite Gigabit Network (ALIGN) Open

Othman Isam Younus, Amna Riaz, Richard Binns, E. Scullion, R. T. Wicks , et al. · 2024

This paper examines the growing adoption of laser communication (lasercom) in space missions and payloads for identifying emerging trends and key technology drivers of future optical communications satellite systems. It also presents a com…

MOSAIC GLAO performance and system architecture: AO for the entire ELT focal plane Open

Nazim A. Bharmal, Tim Morris, T. Butterley, Polly Gill, J. Schmoll , et al. · 2024

International audience

MOSAIC at the ELT: a unique instrument for the largest ground-based telescope Open

R. Pelló, M. Puech, Éric Prieto, M. Rodrigues, Rubén Sánchez-Janssen , et al. · 2024

Pelló, Roser et al.-- Full list of authors: Pelló, Roser; Puech, Mathieu; Prieto, Éric; Rodrigues, Myriam; Sanchez-Janssen, Rubén.; Dalton, Gavin B.; Ducret, Franck; El Hadi, Kacem; García-Vargas, María. L.; Lynn, Jeff; Bharmal, Nazim A.; …

Steering Mirror System with Closed-Loop Feedback for Free-Space Optical Communication Terminals Open

Christopher Graham, David G. Bramall, Othman Isam Younus, Amna Riaz, Richard Binns , et al. · 2024

Precision beam pointing plays a critical role in free-space optical communications terminals in uplink, downlink and inter-satellite link scenarios. Among the various methods of beam steering, the use of fast steering mirrors (FSM) is wide…

Topology Optimization of a Single-Point Diamond-Turning Fixture for a Deployable Primary Mirror Telescope Open

Cyril Bourgenot, Valdis Krumins, David G. Bramall, Abdul M. Haque · 2024

CubeSats, known for their compact size and cost effectiveness, have gained significant popularity. However, their limited size imposes restrictions on the optical aperture and, consequently, the Ground Resolution Distance in Earth Observat…

Topology Optimization Of A Single Point Diamond Turning Fixture For A Deployable Primary Mirror Telescope Open

Cyril Bourgenot, Valdis Krumins, David G. Bramall, Abdul M. Haque · 2023

CubeSats, known for their compact size and cost-effectiveness, have gained significant popularity. However, their limited size imposes restrictions on optical aperture and, consequently, Ground Resolution Distance in Earth Observation miss…

Advances with the WIVERN laboratory experiment for testing novel laser-based wavefront sensing techniques Open

Nazim A. Bharmal, Barr David, David G. Bramall, Ariadna Calcines-Rosario, Sylvain Cetre , et al. · 2023

In order to overcome some existing challenges with the use of laser guide stars (LGS), including complexity,expense, and implementation challenges, we describe in this work WIVERN which is a testbed for laboratoryexperiments in laser-based…

WIVERN: a laboratory experiment for testing novel laser-based wavefront sensing techniques Open

Nazim A. Bharmal, David G. Bramall, Ariadna Z. Calcines Rosario, Tim Morris, J. Schmoll , et al. · 2022

WIVERN is a testbed for laboratory experiments in laser-based wavefront sensing. It emulates laser uplink from a 4m telescope with 1.6 arcsec seeing and laser back-scattering from up to 20 km. Currently there are three current wavefront se…

Performance of the Dark Energy Spectroscopic Instrument (DESI) fiber system Open

Claire Poppett, Patrick N. Jelinsky, J. Guy, Jerry Edelstein, Sharon R. Jelinsky , et al. · 2020

The recently commissioned Dark Energy Spectroscopic Instrument (DESI) will measure the expansion historyof the universe using the Baryon Acoustic Oscillation technique. The spectra of 35 million galaxies and quasarsover 14000 sq deg will b…

A four mirror anastigmat collimator design for optical payload calibration Open

Stephen Rolt, Ariadna Calcines, B. Lomanowski, David G. Bramall · 2016

We present here a four mirror anastigmatic optical collimator design intended for the calibration of an earth observation satellite instrument. Specifically, the collimator is to be applied to the ground based calibration of the Sentinel-4…

An efficient stable optical polariser module for calibration of the S4UVN earth observation satellite Open

Stephen Rolt, Ariadna Calcines, B. Lomanowski, David G. Bramall, Benjamin J. R. Shaw · 2016

We describe here an optical polariser module intended to deliver well characterised polarised light to an imaging spectrometer instrument. The instrument in question is the Sentinel-4/UVN Earth observation imaging spectrometer due to be de…

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