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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.

On-sky results for the integrated microlens ring tip-tilt sensor (2021)
Journal Article
Hottinger, P., Harris, R. J., Crass, J., Dietrich, P., Blaicher, M., Bechter, A., …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., …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., …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., …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.

Identifying optical turbulence profiles for realistic tomographic error in adaptive optics (2019)
Journal Article
Farley, O., Osborn, J., Morris, T., Fusco, T., Neichel, B., Correia, C., & Wilson, R. (2019). Identifying optical turbulence profiles for realistic tomographic error in adaptive optics. Monthly Notices of the Royal Astronomical Society, 488(1), 213-221. https://doi.org/10.1093/mnras/stz1669

For extremely large telescopes, adaptive optics will be required to correct the Earth’s turbulent atmosphere. The performance of tomographic adaptive optics is strongly dependent on the vertical distribution (profile) of this turbulence. An important... Read More about Identifying optical turbulence profiles for realistic tomographic error in adaptive optics.

Efficient implementation of pseudo open loop control for adaptive optics on Extremely Large Telescopes (2019)
Journal Article
Basden, A., Jenkins, D., Morris, T., Osborn, J., & Townson, M. (2019). Efficient implementation of pseudo open loop control for adaptive optics on Extremely Large Telescopes. Monthly Notices of the Royal Astronomical Society, 486(2), 1774-1780. https://doi.org/10.1093/mnras/stz918

Closed-loop adaptive optics systems which use minimum mean square error wavefront reconstruction require the computation of pseudo open loop wavefront slopes. These techniques incorporate a knowledge of atmospheric statistics which must therefore be... Read More about Efficient implementation of pseudo open loop control for adaptive optics on Extremely Large Telescopes.

Optimizing the accuracy and efficiency of optical turbulence profiling using adaptive optics telemetry for extremely large telescopes (2018)
Journal Article
Laidlaw, D. J., Osborn, J., Morris, T. J., Basden, A. G., Beltramo-Martin, O., Butterley, T., …Wilson, R. W. (2018). Optimizing the accuracy and efficiency of optical turbulence profiling using adaptive optics telemetry for extremely large telescopes. Monthly Notices of the Royal Astronomical Society, 483(4), 4341-4353. https://doi.org/10.1093/mnras/sty3285

Advanced adaptive optics (AO) instruments on ground-based telescopes require accurate knowledge of the atmospheric turbulence strength as a function of altitude. This information assists point spread function reconstruction, AO temporal control techn... Read More about Optimizing the accuracy and efficiency of optical turbulence profiling using adaptive optics telemetry for extremely large telescopes.

Representative optical turbulence profiles for ESO Paranal by hierarchical clustering (2018)
Journal Article
Farley, O., Osborn, J., Morris, T., Sarazin, M., Butterley, T., Townson, M., …Wilson, R. (2018). Representative optical turbulence profiles for ESO Paranal by hierarchical clustering. Monthly Notices of the Royal Astronomical Society, 481(3), 4030-4037. https://doi.org/10.1093/mnras/sty2536

Knowledge of the optical turbulence profile is important in adaptive optics (AO) systems, particularly tomographic AO systems such as those to be employed by the next generation of 40-m class extremely large telescopes. Site characterization and moni... Read More about Representative optical turbulence profiles for ESO Paranal by hierarchical clustering.

Compact, modular and in-plane AOSLO for high-resolution retinal imaging (2018)
Journal Article
Young, L. K., Morris, T. J., Saunter, C. D., & Smithson, H. E. (2018). Compact, modular and in-plane AOSLO for high-resolution retinal imaging. Biomedical Optics Express, 9(9), 4275-4293. https://doi.org/10.1364/boe.9.004275

The adaptive optics scanning laser ophthalmoscope (AOSLO) was first developed in 2002 and since then the technology has been adopted in several laboratories around the world, for both clinical and psychophysical research. There have been a few major... Read More about Compact, modular and in-plane AOSLO for high-resolution retinal imaging.

Simulation and optimisation of an astrophotonic reformatter (2018)
Journal Article
Anagnos, T., Harris, R., Corrigan, M., Reeves, A., Townson, M., MacLachlan, D., …Quirrenbach, A. (2018). Simulation and optimisation of an astrophotonic reformatter. Monthly Notices of the Royal Astronomical Society, 478(4), 4881-4889. https://doi.org/10.1093/mnras/sty1396

Image slicing is a powerful technique in astronomy. It allows the instrument designer to reduce the slit width of the spectrograph, increasing spectral resolving power whilst retaining throughput. Conventionally this is done using bulk optics, such a... Read More about Simulation and optimisation of an astrophotonic reformatter.

Centroid error compensation method for a star tracker under complex dynamic conditions (2017)
Journal Article
Tan, W., Qin, S., Myers, R., Morris, T., Jiang, G., Zhao, Y., …Dai, D. (2017). Centroid error compensation method for a star tracker under complex dynamic conditions. Optics Express, 25(26), 33559-33574. https://doi.org/10.1364/oe.25.033559

The traditional approach of a star tracker for reducing the dynamic error concentrates on a single frame of star images. Through correlating adjacent star images together with their angular relations sensed by a gyroscope unit (GU), the attitude-corr... Read More about Centroid error compensation method for a star tracker under complex dynamic conditions.

Wave-front error breakdown in laser guide star multi-object adaptive optics validated on-sky by CANARY (2017)
Journal Article
Martin, O., Gendron, É., Rousset, G., Gratadour, D., Vidal, F., Morris, T., …Henry, D. (2017). Wave-front error breakdown in laser guide star multi-object adaptive optics validated on-sky by CANARY. Astronomy & Astrophysics, 598, Article A37. https://doi.org/10.1051/0004-6361/201629271

Context. Canary is the multi-object adaptive optics (MOAO) on-sky pathfinder developed in the perspective of multi-object spectrograph on extremely large telescopes (ELTs). In 2013, Canary was operated on-sky at the William Herschel telescope (WHT),... Read More about Wave-front error breakdown in laser guide star multi-object adaptive optics validated on-sky by CANARY.

Photometry and Spectrum measurements of the Laser Guide Star beam emission at Observatorio del Roque de Los Muchachos with the Gran Telescope Canarias (2017)
Presentation / Conference Contribution

In the past years ESO has built together with industry a transportable Laser Guide Star Unit (WLGSU) to test the laser technology while supporting some strategic experiments for the LGS-AO technologies. Since July 2016, the WLGSU has been installed a... Read More about Photometry and Spectrum measurements of the Laser Guide Star beam emission at Observatorio del Roque de Los Muchachos with the Gran Telescope Canarias.

Turbulence velocity profiling for high sensitivity and vertical-resolution atmospheric characterization with Stereo-SCIDAR (2016)
Journal Article
Osborn, J., Butterley, T., Townson, M., Reeves, A., Morris, T., & Wilson, R. (2017). Turbulence velocity profiling for high sensitivity and vertical-resolution atmospheric characterization with Stereo-SCIDAR. Monthly Notices of the Royal Astronomical Society, 464(4), 3998-4007. https://doi.org/10.1093/mnras/stw2685

As telescopes become larger, into the era of ∼40 m Extremely Large Telescopes, the high-resolution vertical profile of the optical turbulence strength is critical for the validation, optimization and operation of optical systems. The velocity of atmo... Read More about Turbulence velocity profiling for high sensitivity and vertical-resolution atmospheric characterization with Stereo-SCIDAR.

Efficient photonic reformatting of celestial light for diffraction-limited spectroscopy (2016)
Journal Article
MacLachlan, D., Harris, R., Gris-Sánchez, I., Morris, T., Choudhury, D., Gendron, E., …Thomson, R. (2017). Efficient photonic reformatting of celestial light for diffraction-limited spectroscopy. Monthly Notices of the Royal Astronomical Society, 464(4), 4950-4957. https://doi.org/10.1093/mnras/stw2558

The spectral resolution of a dispersive astronomical spectrograph is limited by the trade-off between throughput and the width of the entrance slit. Photonic guided wave transitions have been proposed as a route to bypass this trade-off, by enabling... Read More about Efficient photonic reformatting of celestial light for diffraction-limited spectroscopy.

Monte-Carlo modelling of multi-object adaptive optics performance on the European Extremely Large Telescope (2016)
Journal Article
Basden, A., & Morris, T. (2016). Monte-Carlo modelling of multi-object adaptive optics performance on the European Extremely Large Telescope. Monthly Notices of the Royal Astronomical Society, 463(4), 4184-4193. https://doi.org/10.1093/mnras/stw2306

The performance of a wide-field adaptive optics system depends on input design parameters. Here we investigate the performance of a multi-object adaptive optics system design for the European Extremely Large Telescope, using an end-to-end Monte-Carlo... Read More about Monte-Carlo modelling of multi-object adaptive optics performance on the European Extremely Large Telescope.

Experience with wavefront sensor and deformable mirror interfaces for wide-field adaptive optics systems (2016)
Journal Article
Basden, A., Atkinson, D., Bharmal, N., Bitenc, U., Brangier, M., Buey, T., …Younger, E. (2016). Experience with wavefront sensor and deformable mirror interfaces for wide-field adaptive optics systems. Monthly Notices of the Royal Astronomical Society, 459(2), 1350-1359. https://doi.org/10.1093/mnras/stw730

Recent advances in adaptive optics (AO) have led to the implementation of wide field-of-view AO systems. A number of wide-field AO systems are also planned for the forthcoming Extremely Large Telescopes. Such systems have multiple wavefront sensors o... Read More about Experience with wavefront sensor and deformable mirror interfaces for wide-field adaptive optics systems.

A tomographic algorithm to determine tip-tilt information from laser guide stars (2016)
Journal Article
Reeves, A., Morris, T., Myers, R., Bharmal, N., & Osborn, J. (2016). A tomographic algorithm to determine tip-tilt information from laser guide stars. Monthly Notices of the Royal Astronomical Society, 459(1), 333-341. https://doi.org/10.1093/mnras/stw622

Laser Guide Stars (LGS) have greatly increased the sky-coverage of Adaptive Optics (AO) systems. Due to the up-link turbulence experienced by LGSs, a Natural Guide Star (NGS) is still required, preventing full sky-coverage. We present a method of obt... Read More about A tomographic algorithm to determine tip-tilt information from laser guide stars.

Photonic spatial reformatting of stellar light for diffraction-limited spectroscopy (2015)
Journal Article
Harris, R., MacLachlan, D., Choudhury, D., Morris, T., Gendron, E., Basden, A., …Thomson, R. (2015). Photonic spatial reformatting of stellar light for diffraction-limited spectroscopy. Monthly Notices of the Royal Astronomical Society, 450(1), 428-434. https://doi.org/10.1093/mnras/stv410

The spectral resolution of a dispersive spectrograph is dependent on the width of the entrance slit. This means that astronomical spectrographs trade-off throughput with spectral resolving power. Recently, optical guided-wave transitions known as pho... Read More about Photonic spatial reformatting of stellar light for diffraction-limited spectroscopy.

Sensitivity improvements for Shack-Hartmann wavefront sensors using total variation minimization (2015)
Journal Article
Basden, A., Morris, T., Gratadour, D., & Gendron, E. (2015). Sensitivity improvements for Shack-Hartmann wavefront sensors using total variation minimization. Monthly Notices of the Royal Astronomical Society, 449(4), 3537-3542. https://doi.org/10.1093/mnras/stv617

We investigate the improvements in Shack–Hartmann wavefront sensor image processing that can be realized using total variation minimization techniques to remove noise from these images. We perform Monte Carlo simulation to demonstrate that at certain... Read More about Sensitivity improvements for Shack-Hartmann wavefront sensors using total variation minimization.

On-sky tests of the CuReD and HWR fast wavefront reconstruction algorithms with CANARY (2015)
Journal Article
Bitenc, U., Basden, A., Bharmal, N., Morris, T., Dipper, N., Gendron, E., …Myers, R. (2015). On-sky tests of the CuReD and HWR fast wavefront reconstruction algorithms with CANARY. Monthly Notices of the Royal Astronomical Society, 448(2), 1199-1205. https://doi.org/10.1093/mnras/stv003

CuReD (Cumulative Reconstructor with domain Decomposition) and HWR (Hierarchical Wavefront Reconstructor) are novel wavefront reconstruction algorithms for the Shack–Hartmann wavefront sensor, used in the single-conjugate adaptive optics. For a high-... Read More about On-sky tests of the CuReD and HWR fast wavefront reconstruction algorithms with CANARY.

Characterising daytime atmospheric conditions on La Palma (2015)
Journal Article
Townson, M., Kellerer, A., Osborn, J., Butterley, T., Morris, T., & Wilson, R. (2015). Characterising daytime atmospheric conditions on La Palma. Journal of Physics: Conference Series, 595, Article 012035. https://doi.org/10.1088/1742-6596/595/1/012035

Day-time turbulence profiles are important for the next generation of Solar Telescopes, which will be equipped with multi conjugate adaptive optics systems. We measured daytime turbulence profiles above La Palma from 17th to 19th September 2013 using... Read More about Characterising daytime atmospheric conditions on La Palma.

Wide-field adaptive optics performance in cosmological deep fields for multi-object spectroscopy with the European Extremely Large Telescope (2014)
Journal Article
Basden, A., Evans, C., & Morris, T. (2014). Wide-field adaptive optics performance in cosmological deep fields for multi-object spectroscopy with the European Extremely Large Telescope. Monthly Notices of the Royal Astronomical Society, 445(4), 4008-4014. https://doi.org/10.1093/mnras/stu2022

A multi-object spectrograph on the forthcoming European Extremely Large Telescope will be required to operate with good sky coverage. Many of the interesting deep cosmological fields were deliberately chosen to be free of bright foreground stars, and... Read More about Wide-field adaptive optics performance in cosmological deep fields for multi-object spectroscopy with the European Extremely Large Telescope.

Characterization of a Commercial, Front-Illuminated Interline Transfer CCD Camera for use as a Guide Camera on a Balloon-Borne Telescope (2014)
Journal Article
Clark, P., Massey, R., Chang, H., Galloway, M., Israel, H., Jones, L., …Susca, S. (2014). Characterization of a Commercial, Front-Illuminated Interline Transfer CCD Camera for use as a Guide Camera on a Balloon-Borne Telescope. Journal of Astronomical Instrumentation, 3(2), Article 1440003. https://doi.org/10.1142/s2251171714400030

We report results obtained during the characterization of a commercial front-illuminated progressive scan interline transfer CCD camera. We demonstrate that the unmodified camera operates successfully in temperature and pressure conditions (-40°C, 4... Read More about Characterization of a Commercial, Front-Illuminated Interline Transfer CCD Camera for use as a Guide Camera on a Balloon-Borne Telescope.

Analysis of on-sky MOAO performance of CANARY using natural guide stars (2014)
Journal Article
Vidal, F., Gendron, E., Rousset, G., Morris, T., Basden, A., Myers, R., …Younger, E. (2014). Analysis of on-sky MOAO performance of CANARY using natural guide stars. Astronomy & Astrophysics, 569, Article A16. https://doi.org/10.1051/0004-6361/201322991

The first on-sky results obtained by CANARY, the multi-object adaptive optics (MOAO) demonstrator, are analysed. The data were recorded at the William Herschel Telescope, at the end of September 2010. We describe the command and calibrations algorith... Read More about Analysis of on-sky MOAO performance of CANARY using natural guide stars.

Open loop tomography with artificial neural networks on CANARY: on-sky results (2014)
Journal Article
Osborn, J., Guzman, D., De Cos Juez, F., Basden, A., Morris, T., Gendron, E., …Rousset, G. (2014). Open loop tomography with artificial neural networks on CANARY: on-sky results. Monthly Notices of the Royal Astronomical Society, 441(3), 2508-2514. https://doi.org/10.1093/mnras/stu758

We present recent results from the initial testing of an artificial neural network (ANN)-based tomographic reconstructor Complex Atmospheric Reconstructor based on Machine lEarNing (CARMEN) on CANARY, an adaptive optics demonstrator operated on the 4... Read More about Open loop tomography with artificial neural networks on CANARY: on-sky results.

Stereo-SCIDAR: optical turbulence profiling with high sensitivity using a modified SCIDAR instrument (2013)
Journal Article
Shepherd, H., Osborn, J., Wilson, R., Butterley, T., Avila, R., Dhillon, V., & Morris, T. (2014). Stereo-SCIDAR: optical turbulence profiling with high sensitivity using a modified SCIDAR instrument. Monthly Notices of the Royal Astronomical Society, 437(4), 3568-3577. https://doi.org/10.1093/mnras/stt2150

The next generation of adaptive optics systems will require tomographic reconstruction techniques to map the optical refractive index fluctuations, generated by the atmospheric turbulence, along the line of sight to the astronomical target. These sys... Read More about Stereo-SCIDAR: optical turbulence profiling with high sensitivity using a modified SCIDAR instrument.

Monte-Carlo simulation of ELT scale multi-object adaptive optics deformable mirror requirements and tolerances (2013)
Journal Article
Basden, A., Bharmal, N., Myers, R., Morris, S., & Morris, T. (2013). Monte-Carlo simulation of ELT scale multi-object adaptive optics deformable mirror requirements and tolerances. Monthly Notices of the Royal Astronomical Society, 435(2), 992-998. https://doi.org/10.1093/mnras/stt1302

Multi-object adaptive optics (MOAO) has been demonstrated by the CANARY instrument on the William Herschel Telescope. However, for proposed MOAO systems on the next-generation extremely large telescopes (ELTs), such as ELT Adaptive optics for GaLaxy... Read More about Monte-Carlo simulation of ELT scale multi-object adaptive optics deformable mirror requirements and tolerances.

WIde-field adaptive optics correction using a single rotating laser guide star (2006)
Journal Article
Morris, T., & Myers, R. (2006). WIde-field adaptive optics correction using a single rotating laser guide star. Monthly Notices of the Royal Astronomical Society, 370(4), 1783-1789. https://doi.org/10.1111/j.1365-2966.2006.10588.x

The problem of providing Adaptive Optics (AO) correction over a wide field of view is one that can be alleviated by using multiple conjugate AO (MCAO), or a low-altitude Laser Guide Star (LGS) that is projected to an altitude below any high layer tur... Read More about WIde-field adaptive optics correction using a single rotating laser guide star.

A Shack-Hartmann wavefront sensor projected on to the sky with reduced focal anisoplanatism (2006)
Journal Article
Butterley, T., Love, G., Wilson, R., Myers, R., & Morris, T. (2006). A Shack-Hartmann wavefront sensor projected on to the sky with reduced focal anisoplanatism. Monthly Notices of the Royal Astronomical Society, 368(2), 837-843. https://doi.org/10.1111/j.1365-2966.2006.10160.x

A method for producing a laser guide star wavefront sensor for adaptive optics with reduced focal anisoplanatism is presented. A theoretical analysis and numerical simulations have been carried out and the results are presented. The technique, named... Read More about A Shack-Hartmann wavefront sensor projected on to the sky with reduced focal anisoplanatism.