&lt;title&gt;Palomar adaptive optics project: status and performance&lt;/title&gt;

Troy, Mitchell; Dekany, Richard; Brack, Gary L.; Oppenheimer, Ben R.; Bloemhof, E. E.; Trinh, Thang; Dekens, Frank; Shi, Fang; Hayward, T. L.; Brandl, Bernhard R.

doi:10.1117/12.390302

Cited by 95 publications

(32 citation statements)

References 4 publications

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“…The Palomar Adaptive-Optics system 21,22 ͑PALAO͒ is a facility-class AO system, developed jointly by the Jet Propulsion Laboratory and Caltech, and has been in use at the f͞15.7 Cassegrain focus of the 5-m telescope since March of 1999. At the time of these experiments, the PALAO routinely achieved 50% K-band Strehl ratios on natural guide stars brighter than 10th magnitude in the presence of 1-arc sec seeing ͑500-nm wavelength͒ and wind velocities of 5-10 m͞s.…”

Section: B Palomar Adaptive-optics Systemmentioning

confidence: 99%

Comparison of measurements of the outer scale of turbulence by three different techniques

Ziad

Schöck²,

Chanan³

et al. 2004

Appl. Opt.

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We have made simultaneous and nearly simultaneous measurements of ᏸ 0 , the outer scale of turbulence, at the Palomar Observatory by using three techniques: angle-of-arrival covariance measurements with the Generalized Seeing Monitor ͑GSM͒, differential-image-motion measurements with the adaptiveoptics system on the Hale 5-m telescope, and fringe speed measurements with the Palomar Testbed Interferometer ͑PTI͒. The three techniques give consistent results, an outer scale of approximately 10 -20 m, despite the fact that the spatial scales of the three instruments vary from 1 m for the GSM to 100 m for the PTI.

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Section: B Palomar Adaptive-optics Systemmentioning

confidence: 99%

Comparison of measurements of the outer scale of turbulence by three different techniques

Ziad

Schöck²,

Chanan³

et al. 2004

Appl. Opt.

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“…(17) ensures that the estimate x in Eq. (15) converges to the correct value in steady state. Taking the z transform of Eq.…”

Section: Local Control Revisitedmentioning

confidence: 82%

“…15 This system has 241 actuators and a 256-element Shack-Hartmann wave-front sensor (D ϭ 16); the actuator and sensor geometry is shown in Fig. 1.…”

Section: Control Problem a Actuators And Sensorsmentioning

confidence: 99%

Local, hierarchic, and iterative reconstructors for adaptive optics

MacMartin

2003

J. Opt. Soc. Am. A

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Adaptive optics systems for future large optical telescopes may require thousands of sensors and actuators. Optimal reconstruction of phase errors using relative measurements requires feedback from every sensor to each actuator, resulting in computational scaling for n actuators of n 2 . The optimum local reconstructor is investigated, wherein each actuator command depends only on sensor information in a neighboring region. The resulting performance degradation on ''global'' modes is quantified analytically, and two approaches are considered for recovering global performance. Combining local and global estimators in a two-layer hierarchic architecture yields computations scaling with n 4/3 ; extending this approach to multiple layers yields linear scaling. An alternative approach that maintains a local structure is to allow actuator commands to depend on both local sensors and prior local estimates. This iterative approach is equivalent to a temporal low-pass filter on global information and gives a scaling of n 3/2 . The algorithms are simulated by using data from the Palomar Observatory adaptive optics system. The analysis is general enough to also be applicable to active optics or other systems with many sensors and actuators.

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“…After decades of development, AO is now in routine operation at all major large-diameter astronomical observatories [11][12][13][14][15][16][17][18].…”

mentioning

confidence: 99%

Laser-Guide-Star Satellite for Ground-Based Adaptive Optics Imaging of Geosynchronous Satellites

Marlow

Carlton

Yoon

et al. 2017

Journal of Spacecraft and Rockets

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In this study, the feasibility and utility of using a maneuverable nanosatellite laser guide star from a geostationary equatorial orbit have been assessed to enable ground-based, adaptive optics imaging of geosynchronous satellites with next-generation extremely large telescopes. The concept for a satellite guide star was first discussed in the literature by Greenaway and Clark in the early 1990s ("PHAROS: An Agile Satellite-Borne Laser Guidestar," Proceedings of SPIE, Vol. 2120, 1994, and expanded upon by Albert in 2012 ("Satellite-Mounted Light Sources as Photometric Calibration Standards for Ground-Based Telescopes," Astronomical Journal, Vol. 143, No. 1, 2012, p. 8). With a satellite-based laser as an adaptive optics guide star, the source laser does not need to scatter, and is well above atmospheric turbulence. When viewed from the ground through a turbulent atmosphere, the angular size of the satellite guide star is much smaller than a backscattered source. Advances in small-satellite technology and capability allowed the revisiting of the concept on a 6U CubeSat, measuring 10 × 20 × 30 cm. It is shown that a system that uses a satellite-based laser transmitter can be relatively low power (∼1 W transmit power) and operated intermittently. Although the preliminary analysis indicates that a single satellite guide star cannot be used for observing multiple astronomical targets, it will only require a little propellant to relocate within the geosynchronous belt. Results of a design study on the feasibility of a small-satellite guide star have been presented, and the potential benefits to astronomical imaging and to the larger space situational awareness community have been highlighted.

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<title>Palomar adaptive optics project: status and performance</title>

Cited by 95 publications

References 4 publications

Comparison of measurements of the outer scale of turbulence by three different techniques

Comparison of measurements of the outer scale of turbulence by three different techniques

Local, hierarchic, and iterative reconstructors for adaptive optics

Laser-Guide-Star Satellite for Ground-Based Adaptive Optics Imaging of Geosynchronous Satellites

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