Outputs (49)

Laboratory demonstration of single-camera PPPP wavefront sensing using neural networks (2024)
Journal Article
Gonzalez-Gutierrez, C., Bharmal, N. A., Rodriguez-Muro, J., Buendia-Roca, A., Yang, H., Fitzpatrick, L. W., Morris, T. J., & de Cos Juez, F. J. (2024). Laboratory demonstration of single-camera PPPP wavefront sensing using neural networks. International Journal of Optomechatronics, 18(1), Article 2386985. https://doi.org/10.1080/15599612.2024.2386985

Laser guide stars in astronomical adaptive optics systems have the focus anisoplanatism problem, especially for telescopes larger than 4 m in diameter. The Projected Pupil Plane Pattern (PPPP) offers an alternative solution by projecting a collimated... Read More about Laboratory demonstration of single-camera PPPP wavefront sensing using neural networks.

HARMONI at ELT: project status and instrument overview (2024)
Presentation / Conference Contribution
Thatte, N. A., Melotte, D., Neichel, B., Le Mignant, D., Rees, P., Clarke, F., Ferraro-Wood, V., Gonzalez, O., Jones, M., Álvarez Urueña, A., Vilaseca, H., Arribas Mocoroa, S., Caballero, J. A., Carracedo Carballal, G. J., Estrada Piqueras, A., Ferro, I., García García, M., Lamperti, I., Pereira Santaella, M., Perna, M., …York, A. (2024, June). HARMONI at ELT: project status and instrument overview. Paper presented at Ground-based and Airborne Instrumentation for Astronomy X, Yokohama, Japan

Adaptive optics telemetry standard: Design and specification of a novel data exchange format (2024)
Journal Article
Gomes, T., Correia, C. M., Bardou, L., Cetre, S., Kolb, J., Kulcsár, C., …Garcia, P. (2024). Adaptive optics telemetry standard: Design and specification of a novel data exchange format. Astronomy & Astrophysics, 686, Article A7. https://doi.org/10.1051/0004-6361/202348486

Context. The amount of adaptive optics (AO) telemetry generated by visible/near-infrared ground-based observatories is ever greater, leading to a growing need for a standardised data exchange format to support performance analysis, AO research, and d... Read More about Adaptive optics telemetry standard: Design and specification of a novel data exchange format.

WIVERN: a laboratory experiment for testing novel laser-based wavefront sensing techniques (2022)
Presentation / Conference Contribution
Bharmal, N. A., Bramall, D., Calcines Rosario, A. Z., Morris, T. J., Schmoll, J., & Staykov, L. (2022, December). WIVERN: a laboratory experiment for testing novel laser-based wavefront sensing techniques. Presented at Adaptive Optics Systems VIII

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 sensing capab... Read More about WIVERN: a laboratory experiment for testing novel laser-based wavefront sensing techniques.

On-sky results for the integrated microlens ring tip-tilt sensor (2021)
Journal Article
Hottinger, P., Harris, R. J., Crass, J., Dietrich, P.-I., Blaicher, M., Bechter, A., Sands, B., Morris, T., Basden, A. G., Bharmal, N. A., Heidt, J., Anagnos, T., Neureuther, P. L., Glück, M., Power, J., Pott, J.-U., Koos, C., Sawodny, O., & Quirrenbach, A. (2021). On-sky results for the integrated microlens ring tip-tilt sensor. Journal of the Optical Society of America B, 38(9), https://doi.org/10.1364/josab.421459

We present the first on-sky results of the microlens ring tip-tilt sensor. This sensor uses a 3D printed microlens ring feeding six multimode fibers to sense misaligned light, allowing centroid reconstruction. A tip-tilt mirror allows the beam to be... Read More about On-sky results for the integrated microlens ring tip-tilt sensor.

First stellar photons for an integrated optics discrete beam combiner at the William Herschel Telescope (2021)
Journal Article
Nayak, A. S., Labadie, L., Sharma, T. K., Piacentini, S., Corrielli, G., Osellame, R., Gendron, É., Buey, J.-T. M., Chemla, F., Cohen, M., Bharmal, N. A., Bardou, L. F., Staykov, L., Osborn, J., Morris, T. J., Pedretti, E., Dinkelaker, A. N., Madhav, K. V., & Roth, M. M. (2021). First stellar photons for an integrated optics discrete beam combiner at the William Herschel Telescope. Applied Optics, 60(19), D129-D142. https://doi.org/10.1364/ao.423881

We present the first on-sky results of a four-telescope integrated optics discrete beam combiner (DBC) tested at the 4.2 m William Herschel Telescope. The device consists of a four-input pupil remapper followed by a DBC and a 23-output reformatter. T... Read More about First stellar photons for an integrated optics discrete beam combiner at the William Herschel Telescope.

Global tip-tilt and high-order aberration correction with plenoptic wavefront sensors in closed-loop AO systems (2021)
Journal Article
Zhang, Z., Morris, T., Bharmal, N., & Liang, Y. (2021). Global tip-tilt and high-order aberration correction with plenoptic wavefront sensors in closed-loop AO systems. Applied Optics, 60(14), 4208 - 4216. https://doi.org/10.1364/ao.420729

The plenoptic wavefront sensor (PlWFS) has been proposed as being suitable for operating on extended objects in adaptive optics (AO) systems. We propose a new self-referencing method that uses the cell image of PlWFS as a correlation reference and en... Read More about Global tip-tilt and high-order aberration correction with plenoptic wavefront sensors in closed-loop AO systems.

Limitations imposed by optical turbulence profile structure and evolution on tomographic reconstruction for the ELT (2020)
Journal Article
Farley, O., Osborn, J., Morris, T., Fusco, T., Neichel, B., Correia, C., & Wilson, R. (2020). Limitations imposed by optical turbulence profile structure and evolution on tomographic reconstruction for the ELT. Monthly Notices of the Royal Astronomical Society, 494(2), 2773-2784. https://doi.org/10.1093/mnras/staa795

The performance of tomographic adaptive optics (AO) systems is intrinsically linked to the vertical profile of optical turbulence. First, a sufficient number of discrete turbulent layers must be reconstructed to model the true continuous turbulence p... Read More about Limitations imposed by optical turbulence profile structure and evolution on tomographic reconstruction for the ELT.

Automated wind velocity profiling from adaptive optics telemetry (2019)
Journal Article
Laidlaw, D. J., Osborn, J., Morris, T. J., Basden, A. G., Gendron, E., Rousset, G., Townson, M. J., & Wilson, R. W. (2020). Automated wind velocity profiling from adaptive optics telemetry. Monthly Notices of the Royal Astronomical Society, 491(1), 1287-1294. https://doi.org/10.1093/mnras/stz3062

Ground-based adaptive optics (AO) systems can use temporal control techniques to greatly improve image resolution. A measure of wind velocity as a function of altitude is needed to minimize the temporal errors associated with these systems. Spatio-te... Read More about Automated wind velocity profiling from adaptive optics telemetry.

Experience with Artificial Neural Networks Applied in Multi-object Adaptive Optics (2019)
Journal Article
Suárez Gómez, S. L., González-Gutiérrez, C., Alonso, E. D., Santos, J. D., Rodríguez, M. L. S., Morris, T., Osborn, J., Basden, A., Bonavera, L., González, J. G.-N., & de Cos Juez, F. J. (2019). Experience with Artificial Neural Networks Applied in Multi-object Adaptive Optics. Publications of the Astronomical Society of the Pacific, 131(1004), Article 108012. https://doi.org/10.1088/1538-3873/ab1ebb

The use of artificial Intelligence techniques has become widespread in many fields of science, due to their ability to learn from real data and adjust to complex models with ease. These techniques have landed in the field of adaptive optics, and are... Read More about Experience with Artificial Neural Networks Applied in Multi-object Adaptive Optics.