The European Southern Observatory gives the opportunity to develop new third generation instruments for the Very Large Telescope Interferometer. Therefore, adaptive optics systems need to be upgraded, either for NAOMI on a 1.8-m auxiliary telescope or for MACAO on a 8-m unit telescope. It enables to access to new science cases such as active galactic nuclei with the GRAVITY+ project. We study here the requirements of such AO upgrade by increasing the number of sub-apertures of the wave-front sensor and the number of actuators of the deformable mirror. We evaluate the needs for a high-Strehl mode in the visible and near infrared wavelengths in various conditions of observation. We present numerical simulations to quantify the performance. We show that a moderate upgrade of NAOMI, and a significant upgrade of MACAO can enable both better dynamic range and sensitivity with the VLTI.
The scientific detector systems for the ESO ELT first-light instruments, HARMONI, MICADO, and METIS, together will require 27 science detectors: seventeen 2.5 μm cutoff H4RG-15 detectors, four 4K x 4K 231-84 CCDs, five 5.3 μm cutoff H2RG detectors, and one 13.5 μm cutoff GEOSNAP detector. This challenging program of scientific detector system development covers everything from designing and producing state-of-the-art detector control and readout electronics, to developing new detector characterization techniques in the lab, to performance modeling and final system verification. We report briefly on the current design of these detector systems and developments underway to meet the challenging scientific performance goals of the ELT instruments.
In this paper, we present our concept of an on-the-fly image processing pipeline for ground-based telescopes. Our focus lies on the correction of undesired but unavoidable detector effects like persistence. State of the art systems like ESO’s NGC perform operation of detectors and acquisition of science data. Instrument operators monitor the science data stream during measurement. Detector issues like persistence worsen the image quality and impair the inspection tasks. To overcome these difficulties, we develop the real-time data processing system EIDAS (Enhanced Infrared Detector Acquisition System) as an add-on to the NGC. Therewith, detector effects in the raw image stream are corrected on-the-fly and astronomical objects are visualized more clearly for direct inspections. EIDAS accompanies CPU, FPGA and GPU as well as algorithms optimized for this hardware architecture. The system is designed generically, matching various types of detectors and their respective science data output
The Teledyne HxRG detectors have versatile and programmable output options to allow operation of them in a variety of configurations such as slow unbuffered, slow buffered, fast buffered or unbuffered modes to optimise the detector performance for a given application. Normally at ESO, for low noise operation, the detectors are operated in slow unbuffered mode. Whilst the slow unbuffered mode offers a simple interface to the external preamplifier electronics, the detector operation in this mode can suffer from reduced pixel frequency response and higher electrical crosstalk between the readout channels. In the context of the detector systems required for the first generation instruments of the ELT (MICADO, HARMONI and METIS), an exercise was undertaken to evaluate the noise, speed and crosstalk performance of the detectors in the slow buffered mode. A test preamplifier has been designed with options to operate a H2RG detector in buffered or unbuffered and with or without using the reference output, so a direct performance comparison can be made between different modes. This paper presents the performance advantages such as increased pixel frequency response, elimination of electrical crosstalk between the readout channels and the noise performance in the buffered mode operation. These improvements allow us to achieve the same frame readout time using half the detector cryogenic electronics and detector controller electronics for the ELT instruments, which significantly reduces the associated cryomechanical complexities in the instrument.
MICADO will enable the ELT to perform diffraction limited near-infrared observations at first light. The instrument’s capabilities focus on imaging (including astrometric and high contrast) as well as single object spectroscopy. This contribution looks at how requirements from the observing modes have driven the instrument design and functionality. Using examples from specific science cases, and making use of the data simulation tool, an outline is presented of what we can expect the instrument to achieve.
MICADO, the Multi-AO-Imaging-Camera and Spectrometer for Deep Observations, is one of the first light instruments for the future 40 m class Extremely Large Telescope (ELT). MICADO utilizes the advanced laser guide star multiconjugate adaptive optics system MCAO developed by the MAORY consortium and the jointly developed singleconjugate adaptive optics system (SCAO). We present an overview on the conceptual design of the MICADO Cold Optical Instrument (COI) which comprises the infrared focal plane imager with its 3 x 3 4k2 HgCdTe detector array and a compact cross-dispersing slit spectrometer operating in the spectral range of 0.8 to 2.4 μm. High contrast imaging is enabled via a classical configuration of coronagraph and Lyot stops. The paper summarizes the MICADO COI interchangeable optics, its cryogenic implementation together with the modular opto-mechanical configuration of the cryo-mechanisms and the cryo-vacuum cooling system, which consists of a continuous LN2 flow cryostat.