The Canary Hosted Upgrade for High-Order Adaptive Optics is an experimental test-bench for high-order SCAO, in R-and I-bands, designed to utilize the Canary experiment at the 4.2m William Herschel Telescope. Chough consists of a pick-off that diverts light from after the 2nd DM in Canary up onto a custom breadboard which hosts the Chough sub-systems. These consist primarily of a ADC, an optical relay, a 1020-actuator DM, a 31 x 31 SH-WFS, and finally a Science Imager. Each of these sub-systems is detailed, with emphasis on interesting and unusual features. As an integrated experiment, the October/2016 on-sky engineering run is first described and then the re-integration of Chough in the laboratory during 2017 as a standalone instrument. In its latter guise, it is a host for additional instrumentation dedicated for high-order AO. An example briefly described is the CAWS interferometer, designed to produce absolute phase residual measurements over a wide chromatic bandwidth (paper #10703-212 in this meeting). We report on consequences of design decisions made for cost reasons, the bench’s fundamental performance, lessons learnt during the various stages of the project so far, and end by describing plans for Chough’s exploitation in the future for high-order SCAO research in the visible and near-IR.
Free-atmosphere, and surface-layer optical-turbulence have been extensively monitored over the years. The
optical-turbulence inside a telescope enclosure en the other hand has yet to be as fully characterized. For this
latest purpose, an experimental concept, LOTUCE (LOcal TUrbulenCe Experiment) has been developed in
order to measure and characterise the so-called dome-seeing. LOTUCE2 is an upgraded prototype whose main
aim is to measure optical turbulence characteristics more precisely by minimising cross-contamination of signals.
This characterisation is both quantitative (optical turbulence strength) and qualitative (assessing the optical
turbulence statistical model). We present the new opto-mechanical design, with the theoretical capabilities and
limitations to the actual models.
The Durham adaptive Optics Real Time Controller (DARC)<sup>1</sup> is a real-time system for astronomical adaptive optics systems originally developed at Durham University and in use for the CANARY instrument. One of its main strengths is to be a generic and high performance real-time controller running on an off-the-shelf Linux computer. We are using DARC for two different implementations: BEAGLE,<sup>2</sup> a Multi-Object AO (MOAO) bench system to experiment with novel tomographic reconstructors and LOTUCE2<sup>,3</sup> an in-dome turbulence instrument. We present the software architecture for each application, current benchmarks and lessons learned for current and future DARC developers.