Status of PRIMA for the VLTI: heading to astrometry

Schmid, Christian; Abuter, R.; Mérand, A.; Alonso, Jaime; Andolfato, Luigi; Belle, Gerard van; Delplancke, F.; Dérie, F.; Lieto, Nicola Di; Frahm, R.; Gitton, Ph.; Gomes, Nuno; Haguenauer, Pierre; Justen, B.; Lévêque, S.; Ménardi, Serge; Morel, S.; Müller, André; Duc, Than Phan; Pozna, Eszter; Ramírez, Andrés; Schuhler, Nicolas; Ségransan, D.

doi:10.1117/12.926426

Cited by 6 publications

(5 citation statements)

References 9 publications

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“…On the left side of Figure 11 fringes of IRS16C (mK=10) are shown which have been taken with the SAPHIRA fringe tracker to stabilize the dispersed science fringes (middle) of the star S2 (mK=14) in the Galactic center, shown as image on the right side. The previous VLTI instrument was PRIMA [17]. It used a PICNIC detector and could do fringe tracking up to a correlated magnitude of mK=8.5 with the 8-meter telescopes, while with GRAVITY the limiting magnitude for fringe tracking is about mK=11.…”

Section: On-sky Performance Of Saphira In Gravitymentioning

confidence: 99%

On-sky performance verification of near infrared eAPD technology for wavefront sensing at ground based telescopes, demonstration of e-APD pixel performance to improve the sensitivity of large science focal planes and possibility to use this technology in space

Finger

Baker

Álvarez

et al. 2019

International Conference on Space Optics — ICSO 2018

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On-sky performance verification of near infrared eAPD technology for wavefront sensing at ground based telescopes, demonstration of e-APD pixel performance to improve the sensitivity of large science focal planes and possibility to use this technology in G. FingerABSTRACT Ground based near infrared adaptive optics as well as fringe tracking for coherent beam combination in optical interferometry required the development of high-speed sensors. Because of the high speed, a large analog bandwidth is needed. The short exposure times result in small signal levels which require noiseless detection. Both of these conflicting requirements cannot be met by state-of-the-art conventional CMOS technology of near infrared arrays as has been attempted previously[1] [2]. The HgCdTe electron avalanche photo diode (eAPD) technology is the only way to overcome the limiting CMOS noise barrier of near infrared sensors. Therefore, ESO funded the development of the near infrared SAPHIRA 320x256 pixel e-APD arrays at LEONARDO [3][4][5][6] [7]. SAPHIRA arrays have now become the devices of choice for control loops with unsurpassed performance [21]. This has also been demonstrated by the four wavefront sensors and the fringe tracker deployed in the VLTI instrument GRAVITY which set a new sensitivity standard in infrared interferometry [8] [9]. It has also been demonstrated that APD arrays have extremely low dark current (1E-3 electrons/s/pixel) and may outperform conventional CMOS arrays for 100 second integrations when operated with moderate APD gains. For AO systems of extremely large telescopes and for co-phasing segmented mirror telescopes larger formats are needed. Therefore, a 512x512 pixel SAPHIRA array with 64 parallel video outputs optimized for pyramid wavefront sensing is in development. Since the SAPHIRA array has successfully passed radiation hardness testing it soon may be used for future instruments in space. Apart from the large array common voltage for high APD gain it can also be operated with voltages compatible with the space qualified SIDECAR ASIC [10].

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Section: On-sky Performance Of Saphira In Gravitymentioning

confidence: 99%

On-sky performance verification of near infrared eAPD technology for wavefront sensing at ground based telescopes, demonstration of e-APD pixel performance to improve the sensitivity of large science focal planes and possibility to use this technology in space

Finger

Baker

Álvarez

et al. 2019

International Conference on Space Optics — ICSO 2018

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“…It consists of star-separator modules at the telescopes (STS 13 ), differential delay lines (DDL 14 ), an internal laser metrology, 15 and the fringe sensor unit (FSU 16 ) in the beam-combination laboratory. The status of the PRIMA facility is presented in [17]. Figure 1 shows the schematic beampath of PRIMA operating with two 1.8 m auxiliary telescopes for astrometry: Two stars within the field-of-view are observed and their light is fed into separate beams by the star separator, which splits the image plane between the stars.…”

Section: Measurement Principle and Implementationmentioning

confidence: 99%

Narrow-angle astrometry with PRIMA

Ségransan

Mérand²,

Zimmerman

et al. 2012

Optical and Infrared Interferometry III

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The Extrasolar Planet Search with PRIMA project (ESPRI) aims at characterising and detecting extrasolar planets by measuring the host star's reflex motion using the narrow-angle astrometry capability of the PRIMA facility at the Very Large Telescope Interferometer. A first functional demonstration of the astrometric mode was achieved in early 2011. This marked the start of the astrometric commissioning phase with the purpose of characterising the instrument's performance, which ultimately has to be sufficient for exoplanet detection. We show results obtained from the observation of bright visual binary stars, which serve as test objects to determine the instrument's astrometric precision, its accuracy, and the plate scale. Finally, we report on the current status of the ESPRI project, in view of starting its scientific programme.Comment: 11 pages, 6 figures. To appear in the proceedings of the 2012 SPIE Conference "Astronomical Telescopes and Instrumentation

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Section: Introductionmentioning

confidence: 99%

“…The status of the instrument and the performance achieved at the time are detailed in Sahlmann et al (2013) [2] . This contribution is in the continuation of Sahlmann et al (2012) [3] , an update of the Extrasolar Planet Search with PRIMA project (ESPRI [4] ), and Schmid et al (2012) [5] , an update of the PRIMA-Astrometry instrument itself. Section 2 presents the modifications made to the metrology of PRIMA to improve the astrometric performance, as well as the impact and correction of major polarization effects.…”

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confidence: 99%

Improving the astrometric performance of VLTI-PRIMA

Woillez¹,

Abuter²,

Andolfato³

et al. 2014

SPIE Proceedings

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In the summer of 2011, the first on-sky astrometric commissioning of PRIMA-Astrometry delivered a performance of 3 m″ for a 10 ″ separation on bright objects, orders of magnitude away from its exoplanet requirement of 50 µ″ ~ 20 µ″ on objects as faint as 11 mag ~ 13 mag in K band. This contribution focuses on upgrades and characterizations carried out since then.The astrometric metrology was extended from the Coudé focus of the Auxillary Telescopes to their secondary mirror, in order to reduce the baseline instabilities and improve the astrometric performance. While carrying out this extension, it was realized that the polarization retardance of the star separator derotator had a major impact on both the astrometric metrology and the fringe sensors. A local compensation of this retardance and the operation on a symmetric baseline allowed a new astrometric commissioning. In October 2013, an improved astrometric performance of 160 µ″ was demonstrated, still short of the requirements. Instabilities in the astrometric baseline still appear to be the dominating factor.In preparation to a review held in January 2014, a plan was developed to further improve the astrometric and faint target performance of PRIMA Astrometry. On the astrometric aspect, it involved the extension of the internal longitudinal metrology to primary space, the design and implementation of an external baseline metrology, and the development of an astrometric internal fringes mode. On the faint target aspect, investigations of the performance of the fringe sensor units and the development of an AO system (NAOMI) were in the plan. Following this review, ESO decided to take a proposal to the April 2014 STC that PRIMA be cancelled, and that ESO resources be concentrated on ensuring that Gravity and Matisse are a success. This proposal was recommended by the STC in May 2014, and endorsed by ESO.

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Status of PRIMA for the VLTI: heading to astrometry

Cited by 6 publications

References 9 publications

On-sky performance verification of near infrared eAPD technology for wavefront sensing at ground based telescopes, demonstration of e-APD pixel performance to improve the sensitivity of large science focal planes and possibility to use this technology in space

On-sky performance verification of near infrared eAPD technology for wavefront sensing at ground based telescopes, demonstration of e-APD pixel performance to improve the sensitivity of large science focal planes and possibility to use this technology in space

Narrow-angle astrometry with PRIMA

Improving the astrometric performance of VLTI-PRIMA

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