Scott Roberts's research while affiliated with United States Naval Observatory and other places

... In addition, GIRMOS will play a significant role for the future development of multiobject spectrograph concepts for the TMT such as IRMOS (Eikenberry et al. 2006) GIRMOS was initially designed as an instrument to be installed behind the Gemini Multi-Conjugate AO system (GeMS, Rigaut et al. 2014) at Cerro Pacon, Chile Sivanandam et al. 2018). However, during the conceptual phase, several points have been identified in favor of a deployment behind the future Gemini North AO system (GNAO, Sivo et al. 2020), at Maunakea, Hawaii (Sivanandam et al. 2020). First, the better atmospheric conditions at Maunakea would enable a significantly improved AO image quality over Gemini South. ...

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The Adaptive Optics System for the Gemini Infrared Multi-Object Spectrograph: Performance Modeling

... Despite these differences, large ground telescopes are precision, opto-mechanical systems, and space telescopes could use similar modeling efforts as these ground-based systems. Angeli et al. [12,13] are developing an integrated modeling environment for cost and performance predictions for large, ground-based telescope systems. They advocate versatile models that can be used for design and can accurately predict relevant performance parameters under typical disturbances. ...

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Integrated Modeling and Design of Lightweight, Active Mirrors for Launch Survival and On-Orbit Performance

... The need to properly quantify and ultimately minimize modeling uncertainty for small error terms by achieving higher precision was evident. Efforts to this end are described in [9] [13] and in sections herein. ...

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On the relationship between thermal seeing and observatory design

... The hexagonal design allows for tight packing of the segments and low weight, at the cost of a greater challenge of aligning and phasing so many mirrors. The TMT system will, for example, have over 10,000 degrees of freedom in the final system, all of which must be operating in precise coordination to achieve the required positioning and alignment of the system [25]. The telescope optical design is that of a Ritchey-Chrétien with an f/1 primary and an f/15 overall focus ratio [26]. ...

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Precision Optics Manufacturing and Control for Next-Generation Large Telescopes

... The atmosphere above the Canary Islands, and especially the western islands Tenerife and La Palma, has been extensively characterized over the past 50 years (Kiepenheuer 1972;McInnes and Walker 1974;Murdin 1985;Brandt and Righini 1985;Stickland et al. 1987;Whittet et al. 1987;Menéndez-Valdés and Blanco 1992;Jímenez et al. 1998;Mahoney et al. 1998;Maring et al. 2000;Torres et al. 2002;Rodríguez et al. 2004;Alonso-Pérez et al. 2007;Basart et al. 2009;Lombardi et al. 2009;Delgado et al. 2010;Vernin et al. 2011;Rodriguez-Franco and Cuevas 2013;Cuevas et al. 2013;Varela et al. 2014;Laken et al. 2016;Vogiatzis et al. 2018;Hidalgo et al. 2021). Due to the combination of large-scale atmospheric circulation on the descending branch of the Hadley cell (see e.g. ...

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Characterizing the aerosol atmosphere above the Observatorio del Roque de los Muchachos by analyzing seven years of data taken with an GaAsP HPD-readout, absolutely calibrated elastic LIDAR

... Though, the knowledge of both temporal and spatial statistics in a general framework can be useful for the development of new analytical expressions to estimate the adaptive optics performance. These tools can help in the analysis of existing Single-Conjugated Adaptive Optics (SCAO) or Wide-Field AO (WFAO) systems [16][17][18][19] and future systems that are going to equip the next generation of telescopes [20][21][22][23][24][25]. Indeed, the classical approach for the analysis of the performance of an AO system is to decompose the overall residual in several sources of errors (temporal, anisoplanatism, noise, aliasing, fitting. . . ...

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Spatiotemporal statistics of the turbulent piston-removed phase and Zernike coefficients for two distinct beams

... In particular, the LGS MCAO current best estimate has been updated i) to further detail the NFIRAOS error terms (such as optical alignment and polishing terms), ii) to include the IRIS wavefront error budget, iii) to include the telescope mechanical vibration budget, and iv) to include the LGSF contribution to the LGS MCAO wavefront error budget and applicable error terms from the AO components, such as the DM dynamic effects. A total of 72 terms for the LGS MCAO wavefront error budget have been assessed through simulations and traced up to requirements [4] . The LGS MCAO wavefront error budget top-level budget is given in Table 1. ...

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Adaptive Optics Program Update at TMT

... The GOGREEN survey is based on a Gemini Large and Long Program using the GMOS instruments (Murowinski et al. 1998;Hook et al. 2004) on Gemini North and South telescopes to obtain unbiased multi-object spectroscopy of galaxies of all types down to stellar masses M * ∼ 10 10.3 M 1 . The survey targets 21 systems spanning a wide range in halo mass at 1.0 < z < 1.5. ...

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The GOGREEN survey: The environmental dependence of the star-forming galaxy main sequence at $1.0<z<1.5

... It should be noted that setting up an adaptive optics system for observation in less than a minute is quite rapid, 2 and the next generation large telescopes all will require an automation of tasks of the same order of magnitude as the Robo-AO robotic system in order to achieve their operational requirements. 3 ...

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The Robo-AO software: Fully autonomous operation of a laser guide star adaptive optics and science system

... For the 39 m diameter Extremely Large Telescope (formerly the European Extremely Large Telescope) under construction on top of Cerro Armazones in northern Chile and other giant telescopes (the Thirty Meter Telescope or the Giant Magellan Telescope), a classical adaptive optics (AO) system reaches its limitations mainly when correction is needed over a large fieldof-view. Other AO concepts called wide-field adaptive optics (WFAO) have been proposed for this large-field compensation for those future ELTs ( [1][2][3]). The optimization of the performance of the WFAO techniques requires a precise specification of the different components of these systems. ...

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PML: a generalized monitor of atmospheric turbulence profile with high vertical resolution