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1. Demonstrating 24-hour continuous vertical monitoring of atmospheric optical turbulence

Author

Griffiths, Ryan, Osborn, James, Farley, Ollie, Butterley, Tim, Townson, Matthew J., and Wilson, Richard

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

We report what is believed to be the first example of fully continuous, 24-hour vertical monitoring of atmospheric optical turbulence. This is achieved using a novel instrument, the 24-hour Shack-Hartmann Image Motion Monitor (24hSHIMM). Optical turbulence is a fundamental limitation for applications such as free-space optical communications, where it limits the achievable bandwidth, and ground-based optical astronomy, restricting the observational precision. Knowledge of the turbulence enables us to select the best sites, design optical instrumentation and optimise the operation of ground-based optical systems. The 24hSHIMM estimates the vertical optical turbulence coherence length, time, angle and Rytov variance from the measurement of a four-layer vertical turbulence profile and a wind speed profile retrieved from meteorological forecasts. To illustrate our advance we show the values of these parameters recorded during a 35-hour, continuous demonstration of the instrument. Due to its portability and ability to work in stronger turbulence, the 24hSHIMM can also operate in urban locations, providing the field with a truly continuous, versatile turbulence monitor for all but the most demanding of applications., Comment: Accepted in Optics Express

Published
2023
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2. Astrosat: Forecasting satellite transits for optical astronomical observations

Author

Osborn, James, Blacketer, Laurence, Townson, Matthew J., and Farley, Ollie J. D.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The impact of large-scale constellations of satellites, is a concern for ground-based astronomers. In recent years there has been a significant increase in the number of satellites in Low-Earth Orbit and this trend is set to continue. The large number of satellites increases the probability that one will enter the field of view of a ground-based telescope at the right solar angle to appear bright enough that it can corrupt delicate measurements. We present a new tool Astrosat that will project satellite orbits onto the RA/DEC coordinate system for a given observer location and time and field of view. This enables observers to mitigate the effects of satellite trails through their images by either avoiding the intersection, post-processing using the information as a prior or shuttering the observation for the duration of the transit. We also provide some analysis on the apparent brightness of the largest of the constellations, Starlink, as seen by a typical observatory and as seen with the naked eye. We show that a naked eye observer can typically expect to see a maximum of 5 Starlink satellites at astronomical twilight, when the sky is dark. With the intended 40000 satellites in the constellation, that number would increase to 30.

Published
2021
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3. Efficient implementation of pseudo open loop control for adaptive optics on Extremely Large Telescopes

Author

Basden, Alastair, Jenkins, David, Morris, Tim, Osborn, James, and Townson, Matthew

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

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 represented within the wavefront slope measurements. These pseudo open loop slopes are computed from the sum of the measured residual slopes and the reconstructed slopes that would be given if the deformable mirror was flat, generally involving the multiplication of an interaction matrix with actuator demands from the previous time-step. When using dense algebra, this multiplication is computationally expensive for Extremely Large Telescopes, requiring a large memory bandwidth. Here we show that this requirement can be significantly reduced, maintaining mathematical correctness and significantly reducing system complexity. This therefore reduces the cost of these systems and increases robustness and reliability., Comment: Accepted for publication in MNRAS

Published
2019
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4. Optimizing the accuracy and efficiency of optical turbulence profiling using adaptive optics telemetry for extremely large telescopes

Author

Laidlaw, Douglas J, Osborn, James, Morris, Timothy J, Basden, Alastair G, Beltramo-Martin, Olivier, Butterley, Timothy, Gendron, Eric, Reeves, Andrew P, Rousset, Gérard, Townson, Matthew J, and Wilson, Richard W

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

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 techniques and is required by wide-field AO systems to optimize the reconstruction of an observed wavefront. The variability of the atmosphere makes it important to have a measure of the optical turbulence profile in real time. This measurement can be performed by fitting an analytically generated covariance matrix to the cross-covariance of Shack-Hartmann wavefront sensor (SHWFS) centroids. In this study we explore the benefits of reducing cross-covariance data points to a covariance map region of interest (ROI). A technique for using the covariance map ROI to measure and compensate for SHWFS misalignments is also introduced. We compare the accuracy of covariance matrix and map ROI optical turbulence profiling using both simulated and on-sky data from CANARY, an AO demonstrator on the 4.2 m William Herschel telescope, La Palma. On-sky CANARY results are compared to contemporaneous profiles from Stereo-SCIDAR - a dedicated high-resolution optical turbulence profiler. It is shown that the covariance map ROI optimizes the accuracy of AO telemetry optical turbulence profiling. In addition, we show that the covariance map ROI reduces the fitting time for an extremely large telescope-scale system by a factor of 72. The software package we developed to collect all of the presented results is now open source.

Published
2019
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5. Optimizing astrophotonic spatial reformatters using simulated on-sky performance

Author

Anagnos, Theodoros, Harris, Robert J., Corrigan, Mark K., Reeves, Andrew P., Townson, Matthew J., MacLachlan, David G., Thomson, Robert R., Morris, Tim J., Schwab, Christian, and Quirrenbach, Andreas

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

One of the most useful techniques in astronomical instrumentation is image slicing. It enables a spectrograph to have a more compact angular slit, whilst retaining throughput and increasing resolving power. Astrophotonic components like the photonic lanterns and photonic reformatters can be used to replace bulk optics used so far. This study investigates the performance of such devices using end-to-end simulations to approximate realistic on-sky conditions. It investigates existing components, tries to optimize their performance and aims to understand better how best to design instruments to maximize their performance. This work complements the recent work in the field and provides an estimation for the performance of the new components., Comment: Conference proceedings in SPIE 2018 Austin Texas

Published
2018
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7. Correlation wavefront sensing and turbulence profiling for solar adaptive optics

Author

Townson, Matthew James

Subjects
621.36
Abstract

Ground based telescopes suffer from degraded resolution due to aberrations induced by the atmosphere which prevent them from reaching the diffraction limit. Adaptive Optics (AO) is a technology which corrects for this effect in real-time, restoring the resolution of a telescope. However, it only corrects for a very narrow field of view (FOV) around the guide source. Tomographic AO uses multiple guide sources to increase the size of the corrected FOV, however, these forms of AO are affected by the vertical distribution of turbulence in the atmosphere (turbulence profile). This thesis presents work to develop turbulence profiling instruments for daytime astronomy and improve centroiding techniques for correlating wavefront sensors (WFS) which are used in slope based turbulence profiling instruments. The development of centroiding techniques for use on extended objects is based on cross-correlation techniques. Two methods are presented, one for optimising centroiding parameters on cross-correlation images and another for improving the signal to noise in cross-correlation images created from images with large relative shifts by using supersized reference images. Choosing optimal centroiding parameters for correlating WFSs is demonstrated in simulation, optimising a windowed, thresholded center of mass. The creation and use of supersized reference images is also demonstrated in simulation, where they are created from WFS data and shown to drastically improve the accuracy of centroiding for centroiding extended objects which have continuous structure across the whole field. So-SLODAR (solar-slope detection and ranging) was developed as a slope based instrument for measuring the turbulence profile on the Swedish Solar Telescope (SST), La Palma. The technique is based on SLODAR, with developments to take advantage of the continuous structure of the solar surface offering multiple guide sources. A full description of the technique and its data reduction is presented, along with the first results from on-sky tests on the SST.

Published
2016

16. CaNaPy facility: opto-mechanical design and requirements for optimal visible systems LGS-AO

Author

Janout, Petr, primary, Martinez Rey, Noelia, additional, Bonaccini Calia, Domenico, additional, Hinterschuster, Renate, additional, Dieter Conzelmann, Ralf, additional, Pinna, Enrico, additional, Bonaglia, Marco, additional, Reyes García-Talavera, Marcos, additional, Townson, Matthew, additional, Osborn, James, additional, Faccini, Marco, additional, and Centrone, Mauro, additional

Published
2022
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17. CaNaPy: LGS-AO experimental facility for visible wavelengths

Author

Bonaccini Calia, Domenico, primary, Osborn, James, additional, Haguenauer, Pierre, additional, Reyes García-Talavera, Marcos, additional, Alaluf, David, additional, Centrone, Mauro, additional, Martínez Rey, Noelia, additional, Jenkins, David R., additional, Janout, Petr, additional, Faccini, Marco, additional, Puglisi, Alfio ., additional, Jost, Andreas, additional, Agapito, Guido, additional, Hinterschuster, Renate, additional, Conzelmann, Ralf D., additional, Guidolin, Ivan M., additional, Townson, Matthew J., additional, Bonaglia, Marco, additional, Pinna, Enrico, additional, Ambrosino, Filippo, additional, Rodríguez Ramos, Luis Fernando, additional, and Hackenberg, Wolfgang K., additional

Published
2022
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18. HARMONI at ELT: overview of the capabilities and expected performance of the ELT's first light, adaptive optics assisted integral field spectrograph.

Author

Thatte, Niranjan ., primary, Melotte, Dave, additional, Neichel, Benoit, additional, Le Mignant, David, additional, Bryson, Ian, additional, Clarke, Fraser, additional, Ferraro-Wood, Vanessa, additional, Fusco, Thierry, additional, Gonzalez, Oscar, additional, Schnetler, Hermine, additional, Tecza, Matthias, additional, Wilson, Sandi, additional, Álvarez Urueña, Alonso, additional, Vilaseca, Heribert A., additional, Arribas Mocoroa, Santiago, additional, Carracedo Carballale, Gonzalo José, additional, Crespo, Alejandro, additional, Estrada Piqueras, Alberto, additional, García García, Miriam, additional, Martínez Martín, Cecilia, additional, Pereira Santaella, Miguel, additional, Perna, Michele, additional, Piqueras López, Javier, additional, Bouché, Niolas, additional, Boudon, Didier, additional, Daguisé, Eric, additional, Disseau, Karen, additional, Fensch, Jérémy J., additional, Girardot, Adrien, additional, Guibert, Matthieu, additional, Jarno, Aurélien, additional, Jeanneau, Alexandre, additional, Krogager, Jens-Kristian, additional, Laurent, Florence, additional, Loupias, Magali, additional, Migniau, Jean-Emmanuel, additional, Piqueras, Laure, additional, Remillieux, Alban, additional, Richard, Johan, additional, Pecontal, Arlette, additional, Bardou, Lisa F., additional, Barr, David, additional, Cetre, Sylvain, additional, Deshmukh, Rishi, additional, Dimoudi, Sofia, additional, Dubbledam, Marc, additional, Dunn, Andrew, additional, Gadotti, Dimitra, additional, Guy, Joss J., additional, King, David L., additional, Little, David J., additional, McLeod, Anna, additional, Morris, Simon, additional, Morris, Tim, additional, O'Brien, Kieran S., additional, Ronson, Emily, additional, Smith, Russell, additional, Staykov, Lazar, additional, Swinbank, Mark, additional, Townson, Matthew, additional, Accardo, Matteo, additional, Alvarez Mendez, Domingo, additional, George, Elizabeth, additional, Hopgood, Joshua, additional, Ives, Derek, additional, Mehrgan, Leander, additional, Mueller, Eric, additional, Reyes-Moreno, Javier, additional, Conzelmann, Ralf, additional, Gutierrez Cheetham, Pablo, additional, Alonso-Sánchez, Ángel, additional, Battaglia, Giuseppina, additional, Cagigas Garcia, Miguel Angel, additional, Chulani, Haresh M., additional, Delgado García, Graciela C., additional, Fernández-Izquierdo, Patricia, additional, Fragoso López, Ana Belén, additional, García-Lorenzo, Begoña, additional, Hernández González, Alberto, additional, Hernández Suárez, Elvio, additional, Herreros Linares, Jose Miguel, additional, Joven, Enrique, additional, López López, Roberto, additional, Lujan Gonzalez, Alejandro Antonio, additional, Martín, Yolanda, additional, Mediavilla, Evencio, additional, Menéndez Mendoza, Saúl, additional, Montoya Martínez, Luz Maria, additional, Peñate Castro, José, additional, Pérez, Álvaro, additional, Rasilla, José Luis, additional, Rebolo-López, Rafael, additional, Rodríguez-Ramos, Luis Fernando, additional, Vega Moreno, Afrodisio, additional, Viera-Curbelo, Teodora, additional, Zanon Dametto, Natacha, additional, Carlotti, Alexis, additional, Correia, Jean-Jacques, additional, Curaba, Stéphane, additional, Delboulbé, Alain, additional, Guieu, Sylvain, additional, Hours, Adrien, additional, Hubert, Zoltan, additional, Jocou, Laurent, additional, Magnard, Yves, additional, Moulin, Thibaut, additional, Pancher, Fabrice, additional, Rabou, Patrick, additional, Stadler, Eric, additional, Vérove, Maxime, additional, Contini, Thierry, additional, Larrieu, Marie, additional, Boebion, Olivier, additional, Fantéï-Caujolle, Yan, additional, Lecron, Daniel, additional, Rousseau, Sylvain, additional, Amram, Philippe, additional, Beltramo-Martin, Olivier, additional, Bon, William, additional, Bonnefoi, Anne, additional, Ceria, William, additional, Challita, Zalpha, additional, Charles, Yannick, additional, Choquet, Elodie, additional, Correia, Carlos, additional, Costille, Anne, additional, Dohlen, Kjetil, additional, Ducret, Franck, additional, El Hadi, Kacem, additional, Gach, Jean-Luc, additional, Gimenez, Jean-Luc, additional, Groussin, Olivier, additional, Jaquet, Marc, additional, Jouve, Pierre, additional, Madec, Fabrice, additional, Pedreros Bustos, Felipe, additional, Renault, Edgard, additional, Sanchez, Patrice, additional, Vigan, Arthur, additional, Vola, Pascal, additional, Zavago, Annie, additional, Fétick, Romain, additional, Lim, Caroline, additional, Petit, Cyril, additional, Sauvage, Jean-Francois, additional, Védrenne, Nicolas, additional, Bagci, Fehim Taha, additional, Caldwell, Martin E., additional, Elliott, Ellis, additional, Hiscock, Peter, additional, Johnson, Emma, additional, Nalagatla, Murali, additional, Seitis, Aristea, additional, Wells, Mark, additional, Black, Martin, additional, Bond, Charlotte Z., additional, Brierley, Saskia, additional, Campbell, Kenneth, additional, Campbell, Neil, additional, Carruthers, James, additional, Cochrane, William, additional, Evans, Chris, additional, Harman, Joel, additional, Humphreys, William, additional, Louth, Thomas, additional, Miller, Chris, additional, Montgomery, David, additional, Murali, Meenu, additional, Murray, John, additional, O'Malley, Norman, additional, Sanchez-Janssen, Ruben, additional, Schwartz, Noah, additional, Smith, Patrick, additional, Strachan, Jonathan, additional, Todd, Stephen, additional, Watt, Stuart, additional, Wells, Martyn, additional, Yaqoob, Asim, additional, Bell, Eric, additional, Gnedin, Oleg O., additional, Gultekin, Kayhan, additional, Mateo, Mario, additional, Meyer, Michael, additional, Ahmad, Munadi, additional, Birkby, Jayne, additional, Booth, Michael, additional, Cappellari, Michele, additional, Castillo Dominguez, Edgar, additional, Chao Ortiz, Jorge, additional, Gooding, David, additional, Grisdale, Kearn, additional, Hidalgo Valadez, Andrea, additional, Hogan, Laurence, additional, Kariuki, James, additional, Lewis, Ian, additional, Lowe, Adam, additional, Ozer, Zeynep, additional, Routledge, Laurence, additional, Rigopoulou, Dimitra, additional, and York, Alec, additional

Published
2022
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19. HARMONI- the Extremely Large Telescope first light integral field spectrograph: a novel functional model based system engineering methodology for the design of an integrated instrument control system architecture

Author

Schnetler, Hermine, primary, Bond, Charlotte, additional, Chulani, Haresh, additional, Clarke, Fraser, additional, Costille, Anne, additional, Delgado Garcia, Graciela, additional, Delgado, Jose Miguel, additional, Dimoudi, Sofia, additional, Dunn, Andrew, additional, George, Elizabeth, additional, Estrada Piqueras, Alberto, additional, Guieu, Sylvain, additional, Joven, Enrique, additional, Larrieu, Marie, additional, Martín Hernando, Yolanda, additional, Martínez Martín, Cecilia, additional, Menéndez Mendoza, Saul, additional, Miller, Chris, additional, Morris, Tim, additional, Pecontal, Arlette, additional, Piqueras López, Javier, additional, Rodríguez Ramos, Luis Fernando, additional, Stegmeier, Jörg, additional, Townson, Matthew, additional, Viera Cuberlo, Teodora, additional, Fusco, Thierry, additional, Le Mignant, David, additional, Neichel, Benoit, additional, Melotte, Dave, additional, Tecza, Matthias, additional, and Thatte, Niranjan, additional

Published
2022
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22. ELT-scale elongated LGS wavefront sensing: on-sky results

Author

Bardou, Lisa, primary, Gendron, Éric, additional, Rousset, Gérard, additional, Gratadour, Damien, additional, Basden, Alastair, additional, Bonaccini Calia, Domenico, additional, Buey, Tristant, additional, Centrone, Mauro, additional, Chemla, Fanny, additional, Gach, Jean-Luc, additional, Geng, Deli, additional, Hubert, Zoltán, additional, Laidlaw, Douglas J., additional, Morris, Timothy J., additional, Myers, Richard M., additional, Osborn, James, additional, Reeves, Andrew P., additional, Townson, Matthew J., additional, and Vidal, Fabrice, additional

Published
2021
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25. HARMONI: first light spectroscopy for the ELT: instrument final design and quantitative performance predictions

Author

Thatte, Niranjan, primary, Bryson, Ian, additional, Clarke, Fraser, additional, Ferraro-Wood, Vanessa, additional, Fusco, Thierry, additional, Le Mignant, David, additional, Melotte, Dave J., additional, Neichel, Benoit, additional, Schnetler, Hermine, additional, Tecza, Matthias, additional, Arribas, Santiago, additional, Crespo, Alejandro, additional, Estrada Piqueras, Alberto, additional, García García, Miriam, additional, Pereira Santaella, Miguel, additional, Piqueras López, Javier, additional, Blaizot, Jeremy, additional, Bouché, Nicholas, additional, Boudon, Didier, additional, Chapuis, Diane, additional, Daguise, Eric, additional, Disseau, Karen, additional, Guibert, Mtthieu, additional, Jarno, Aurelien, additional, Jeanneau, Alexandre, additional, Laurent, Florence, additional, Loupias, Magali, additional, Migniau, Jean-Emmanuel, additional, Piqueras, Laure, additional, Remillieux, Alban, additional, Richard, Johan, additional, Pécontal-Rousset, Arlette, additional, Bardou, Lisa, additional, Close, Madeline M., additional, Deshmukh, Rishi, additional, Dimoudi, Sofia, additional, Dubbledam, Marc, additional, King, David, additional, Morris, Simon, additional, Morris, Timothy J., additional, O'Brien, Kieran S., additional, Staykov, Lazar, additional, Swinbank, Mark, additional, Townson, Matthew, additional, Younger, Eddy, additional, Accardo, Matteo, additional, Avarez Mendez, Domingo, additional, Conzelmann, Ralf, additional, Egner, Sebastian, additional, George, Elizabeth M., additional, Gonté, Frederic, additional, Hopgood, Joshua, additional, Ives, Derek, additional, Mehrgan, Leander, additional, Mueller, Eric, additional, Peroux, Celine, additional, Vernet, Joel, additional, Alonso-Sánchez, Ángel, additional, Giuseppina, Battaglia, additional, Cagigas, Miguel, additional, Delgado, Jose Miguel, additional, Fernandez Izquierdo, Patricia, additional, Fragoso López, Ana Belén, additional, García-Lorenzo, Maria Begoña, additional, Hernandez Suarez, Elvio, additional, Herreros Linares, José Miguel, additional, Joven, Enrique, additional, López, Roberto, additional, Martín Hernando, Yolanda, additional, Mediavilla, Evencio, additional, Monreal, Ana, additional, Peñate Castro, José, additional, Rasilla, Jose Luis, additional, Rebolo, Rafael, additional, Rodríguez-Ramos, Luis Fernando, additional, Vega Moreno, Afrodisio, additional, Viera, Teodora, additional, Carlotti, Alexis, additional, Correia, Jean-Jacques, additional, Delboulbe, Alain, additional, Guieu, Sylvain, additional, Hours, Adrien, additional, Hubert, Zoltan, additional, Jocou, Laurent, additional, Magnard, Yves, additional, Moulin, Thibaut, additional, Pancher, Fabrice, additional, Rabou, Patrick, additional, Stadler, Eric, additional, Contini, Thierry, additional, Larrieu, Marie, additional, Fantei-Caujolle, Yan, additional, Lecron, Daniel, additional, Rousseau, Sylvain, additional, Beltramo-Martin, Olivier, additional, Bon, William, additional, Bonnefoi, Anne, additional, Ceria, William, additional, Choquet, Elodie, additional, Correia, Carlos, additional, Costille, Anne, additional, Dohlen, Kjetil, additional, Ducret, Franck, additional, El Hadi, Kacem, additional, Epinat, Benoit, additional, Fetick, Romain, additional, Gach, Jean-Luc, additional, Groussin, Oliver, additional, Jaafar, Issa, additional, Le Merrer, Joel, additional, Llored, Marc, additional, Pedreros, Felipe, additional, Renault, Edgard, additional, Sanchez, Patrice, additional, Vigan, Arthur, additional, Vola, Pascal, additional, Lim, Caroline, additional, Vedrenne, Nicola, additional, Petit, Cyril, additional, Sauvage, Jean-Francois, additional, Bagci, Taha, additional, Cann, Nick, additional, Chao Ortiz, Jorge, additional, Elliott, Ellis, additional, Seitis, Tea, additional, Tosh, Ian, additional, Anderson, Josh, additional, Black, Martin, additional, Bond, Charlotte, additional, Born, Andy J., additional, Campbell, Kenny, additional, Campbell, Neil, additional, Carruthers, James, additional, Cochrane, William, additional, Dobson, Naomi, additional, Evans, Chris J., additional, Gallie, Angus, additional, Gonzalez, Oscar, additional, Harman, Joel, additional, Henry, David M., additional, Humphreys, William, additional, Louth, Tom, additional, Miller, Chris, additional, Montgomery, David M., additional, Murray, John, additional, O'Malley, Norman, additional, Ritchie, Lynn, additional, Sanchez-Janssen, Ruben, additional, Schwartz, Noah, additional, Smith, Patrick, additional, Watt, Stuart, additional, Wells, Martyn, additional, Wilson, Sandi, additional, Gultekin, Kayhan K., additional, Mateo, Mario L., additional, Meyer, Michael, additional, Valluri, Monica, additional, Ahmad, Munadi, additional, Booth, Michael, additional, Capone, John I., additional, Cappellari, Michele, additional, Gooding, David, additional, Grisdale, Kearn, additional, Hidalgo, Andrea, additional, Kariuki, James, additional, Lewis, Ian, additional, Lowe, Adam, additional, Lynn, Jim, additional, Menduina, Alvaro, additional, Ozer, Zeynep, additional, Preece, Roy, additional, Rigopoulou, Dimitra, additional, Rodrigues, Myriam, additional, and Routledge, Laurence, additional

Published
2020
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26. Astrosat: forecasting satellite transits for optical astronomical observations.

Author

Osborn, James, Blacketer, Laurence, Townson, Matthew J, and Farley, Ollie J D

Subjects
ASTRONOMICAL observations, ASTRONOMICAL transits, SOLAR telescopes, FORECASTING, HAWTHORNE effect, LOW earth orbit satellites, OBSERVATORIES
Abstract

The impact of large-scale constellations of satellites, is a concern for ground-based astronomers. In recent years there has been a significant increase in the number of satellites in low-Earth orbit and this trend is set to continue. The large number of satellites increases the probability that one will enter the field of view of a ground-based telescope at the right solar angle to appear bright enough that it can corrupt delicate measurements. We present a new tool 'Astrosat' that will project satellite orbits onto the RA/Dec. coordinate system for a given observer location and time and field of view. This enables observers to mitigate the effects of satellite trails through their images by either avoiding the intersection, post-processing using the information as a prior or shuttering the observation for the duration of the transit. We also provide some analysis on the apparent brightness of the largest of the constellations, Starlink, as seen by a typical observatory and as seen with the naked eye. We show that a naked eye observer can typically expect to see a maximum of 5 Starlink satellites at astronomical twilight, when the sky is dark. With the intended 40 000 satellites in the constellation that number would increase to 30. [ABSTRACT FROM AUTHOR]

Published
2022
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30. Optimizing the accuracy and efficiency of optical turbulence profiling using adaptive optics telemetry for extremely large telescopes

Author

Laidlaw, Douglas J, primary, Osborn, James, additional, Morris, Timothy J, additional, Basden, Alastair G, additional, Beltramo-Martin, Olivier, additional, Butterley, Timothy, additional, Gendron, Eric, additional, Reeves, Andrew P, additional, Rousset, Gérard, additional, Townson, Matthew J, additional, and Wilson, Richard W, additional

Published
2018
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31. Automated wind velocity profiling from adaptive optics telemetry.

Author

Laidlaw, Douglas J, Osborn, James, Morris, Timothy J, Basden, Alastair G, Gendron, Eric, Rousset, Gérard, Townson, Matthew J, and Wilson, Richard W

Subjects
WIND speed, ADAPTIVE optics, TELEMETRY, LONG-range weather forecasting, DOPPLER lidar, TELESCOPES, INTEGRATED software
Abstract

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-temporal analysis of AO telemetry can express the wind velocity profile using the slope detection and ranging (SLODAR) technique. However, the limited altitude-resolution of current AO systems makes it difficult to disentangle the movement of independent layers. It is therefore a challenge to create an algorithm that can recover the wind velocity profile through SLODAR data analysis. In this study, we introduce a novel technique for automated wind velocity profiling from AO telemetry. Simulated and on-sky centroid data from CANARY – an AO testbed on the 4.2 m William Herschel telescope, La Palma – is used to demonstrate the proficiency of the technique. Wind velocity profiles measured on-sky are compared to contemporaneous measurements from Stereo-SCIDAR, a dedicated high-resolution atmospheric profiler. They are also compared to European centre for medium-range weather forecasts. The software package that we developed to complete this study is open source. [ABSTRACT FROM AUTHOR]

Published
2020
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32. Phase A AO system design and performance for MOSAIC at the ELT

Author

Morris, Timothy J., primary, Gendron, Éric, primary, Morel, Carine, primary, Fusco, Thierry, primary, Rousset, Gérard, primary, Dohlen, Kjetil, primary, El Hadi, Kacem, primary, Vola, Pascal, primary, Basden, Alastair G., primary, Townson, Matthew J., primary, Jenkins, David R., primary, Dubbeldam, Cornelis M., primary, Calcines-Rosario, Ariadna, primary, Morris, Simon L., primary, Fitzsimons, Ewan D., primary, Hammer, François, primary, Jagourel, Pascal, primary, and Younger, Edward, primary

Published
2018
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33. Multi-node homogeneous Xeon Phi architecture for ELT scale Adaptive Optics RTC (Conference Presentation)

Author

Jenkins, David, primary, Basden, Alastair G., additional, Myers, Richard M., additional, Osborn, James, additional, Townson, Matthew J., additional, Reeves, Andrew P., additional, Staykov, Lazar, additional, Younger, Edward J., additional, Geng, Deli, additional, Dipper, Nigel A., additional, Gratadour, Damien, additional, Sevin, Arnaud, additional, and Perret, Denis, additional

Published
2018
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34. Closed loop operation with extremely elongated LGS spots in CANARY Phase D

Author

Basden, Alastair G., primary, Bardou, Lisa, primary, Buey, Jean-Tristan M., primary, Castro-Almazán, Julio A., primary, Centrone, Mauro, primary, Chemla, Fanny, primary, Bonaccini Calia, Domenico, primary, Gach, Jean-Luc, primary, Gendron, Éric, primary, Geng, Deli, primary, Hubert, Zoltán, primary, Laidlaw, Douglas J., primary, Lombardi, Gianluca, primary, Morris, Timothy J., primary, Myers, Richard M., primary, Osborn, James, primary, Reeves, Andrew P., primary, Rousset, Gérard, primary, Sevin, Arnaud, primary, Townson, Matthew J., primary, and Vidal, Fabrice, primary

Published
2018
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35. Error breakdown of ELT-elongated LGS wavefront-sensing using CANARY on-sky measurements

Author

Bardou, Lisa, primary, Gendron, Éric, primary, Rousset, Gérard, primary, Gratadour, Damien, primary, Basden, Alastair G., primary, Bonaccini Calia, Domenico, primary, Buey, Jean-Tristan M., primary, Centrone, Mauro, primary, Chemla, Fanny, primary, Gach, Jean-Luc, primary, Geng, Deli, primary, Hubert, Zoltán, primary, Laidlaw, Douglas J., primary, Morris, Timothy J., primary, Myers, Richard M., primary, Osborn, James, primary, Reeves, Andrew P., primary, Townson, Matthew J., primary, and Vidal, Fabrice, primary

Published
2018
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36. Prototyping AO RTC using emerging high performance computing technologies with the Green Flash project

Author

Gratadour, Damien, primary, Osborn, James, primary, Deneux, Hugues, primary, Biasi, Roberto, primary, Perret, Denis, primary, Sevin, Arnaud, primary, Morris, Timothy J., primary, Younger, Edward J., primary, Rouaud, Christophe, primary, Buey, Jean-Tristan M., primary, Pretet, Damien, primary, Lemaitre, Jerome, primary, Palazzari, Paolo, primary, Patauner, Christian, primary, Townson, Matthew J., primary, Geng, Deli, primary, Staykov, Lazar, primary, Basden, Alastair G., primary, Pescoller, Dietrich, primary, Andrighettoni, Mario, primary, Bernard, Julien, primary, Lainé, Maxime, primary, Ferreira, Florian, primary, and Doucet, Nicolas, primary

Published
2018
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38. An ELT scale MCAO real-time control prototype using Xeon Phi technologies

Author

Jenkins, David R., primary, Basden, Alastair G., primary, Myers, Richard M., primary, Osborn, James, primary, Townson, Matthew J., primary, Reeves, Andrew P., primary, Staykov, Lazar, primary, Younger, Edward J., primary, Geng, Deli, primary, Dipper, Nigel A., primary, Gratadour, Damien, primary, Sevin, Arnaud, primary, and Perret, Denis, primary

Published
2018
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39. Representative atmospheric turbulence profiles for ESO Paranal

Author

Farley, Ollie, primary, Osborn, James, primary, Wilson, Richard W., primary, Butterley, Timothy, primary, Laidlaw, Douglas J., primary, Townson, Matthew J., primary, Morris, Timothy J., primary, Le Louarn, Miska, primary, Chacón-Oelckers, Arlette, primary, Haubois, Xavier, primary, Navarrete, Julio, primary, Milli, Julien, primary, Sarazin, Marc, primary, and Derie, Frédéric, primary

Published
2018
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43. Photometry and Spectrum measurements of the Laser Guide Star beam emission at Observatorio del Roque de Los Muchachos with the Gran Telescopio CANARIAS

Author

Lombardi, Gianluca, primary, Bonaccini Calia, Domenico, additional, Centrone, Mauro, additional, Reyes Garcia Talavera, Marcos, additional, Morris, Tim, additional, Pfrommer, Thomas, additional, Basden, Alastair, additional, Vidal, Fabrice, additional, Gendron, Eric, additional, Rousset, Gerard, additional, Mayers, Richard, additional, Osborn, James, additional, Reeves, Andrew, additional, Talbot, Robert, additional, Townson, Matthew, additional, Cabrera Lavers, Antonio, additional, and de Ugarte Postigo, Antonio, additional

Published
2017
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44. Preliminary on-sky results of the CANARY experiment with an ELT-elongated sodium LGS

Author

Bardou, Lisa, primary, Gendron, Éric, additional, Rousset, Gérard, additional, Gratadour, Damien, additional, Basden, Alastair G., additional, Bonaccini Calia, Domenico, additional, Buey, Tristan, additional, Centrone, Mauro, additional, Chemla, Fanny, additional, Gach, Jean-Luc, additional, Lombardi, Gianluca, additional, Marchetti, Enrico, additional, Morris, Timothy J., additional, Myers, Richard M., additional, Osborn, James, additional, Townson, Matthew, additional, Vidal, Fabrice, additional, and Reyes García-Talavera, Marcos, additional

Published
2017
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48. Turbulence profiling for adaptive optics tomographic reconstructors

Author

Laidlaw, Douglas J., additional, Osborn, James, additional, Wilson, Richard W., additional, Morris, Timothy J., additional, Butterley, Timothy, additional, Reeves, Andrew P., additional, Townson, Matthew J., additional, Gendron, Éric, additional, Vidal, Fabrice, additional, and Morel, Carine, additional

Published
2016
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49. ALASCA: the ESA Laser Guide Star Adaptive Optics Optical Feeder Link demonstrator facility

Author

Minoglou, Kyriaki, Karafolas, Nikos, Cugny, Bruno, Biasi, Roberto, Bonaccini Calia, Domenico, Centrone, Mauro, Enderlein, Martin, Faccini, Marco, Farley, Ollie J., Gallieni, Daniele, Gooding, D., Haguenauer, Pierre, Janout, Petr, Jenkins, David, Lison, Frank, Luis, J., Martinez Rey, Noelia, Osborn, James, Patauner, Christian, Pescoller, Dietrich, Reyes, M., Sabatini, L., Salvi, L., Sodnik, Zoran, Alaluf, David, Tintori, Matteo, Tordi, M., Townson, Matthew, Virdee, Hira, Wei, Daoping, and Clements, Wallace R.

Published
2023
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