arXiv subjects

Stefan Schlenstedt

Publications and source records attributed to Stefan Schlenstedt.

3 recordsLinked to original sources

arXiv2016

Techniques And Results For The Calibration Of The MST Prototype For The Cherenkov Telescope Array

The next generation instrument for ground-based gamma-ray astronomy will be the Cherenkov Telescope Array (CTA), consisting of approximately 100 telescopes in three sizes, built on two sites with one each in the Northern and Southern Hemi- spheres. Up to 40 of these will be Medium Size Telescopes (MSTs) which will dominate sensitivity in the core energy range. Since 2012, a full size mechanical prototype for the modified 12 m Davies-Cotton design MST has been in operation in Berlin. This doc- ument describes the techniques which have been implemented to calibrate and optimise the mechanical and optical performance of the prototype, and gives the results of over three years of observations and measurements. Pointing calibration techniques will be discussed, along with the development of a bending model, and calibration of the CCD cameras used for pointing measurements. Additionally alignment of mirror segments using the Bokeh method is shown.

astro-ph.IM↗

arXiv2015

Status of the Medium-Sized Telescope for the Cherenkov Telescope Array

The Cherenkov Telescope Array (CTA), is an international project for the next generation ground- based observatory for gamma-ray astronomy in the energy range from 20 GeV to 300 TeV. The sensitivity in the core energy range will be dominated by up to 40 Medium-Sized Telescopes (MSTs). The MSTs, of Davies-Cotton type with a 12 m diameter reflector are currently in the prototype phase. A full-size mechanical telescope structure has been assembled in Berlin. The telescope is partially equipped with different mirror prototypes, which are currently being tested and evaluated for performances characteristics. A report concentrating on the details of the tele- scope structure, the drive assemblies and the optics of the MST prototype will be given.

astro-ph.IM↗

arXiv2013

Pointing Calibration for the Cherenkov Telescope Array Medium Size Telescope Prototype

Pointing calibration is an offline correction applied in order to obtain the true pointing direction of a telescope. The Cherenkov Telescope Array (CTA) aims to have the precision to determine the position of point-like as well as slightly extended sources, with the goal of systematic errors less than 7 arc seconds in space angle. This poster describes the pointing calibration concept being developed for the CTA Medium Size Telescope (MST) prototype at Berlin-Adlershof, showing test results and preliminary measurements. The MST pointing calibration method uses two CCD cameras, mounted on the telescope dish, to determine the true pointing of the telescope. The "Lid CCD" is aligned to the optical axis of the telescope, calibrated with LEDs on the dummy gamma-camera lid; the "Sky CCD" is pre-aligned to the Lid CCD and the transformation between the Sky and Lid CCD camera fields of view is precisely modelled with images from special pointing runs which are also used to determine the pointing model. During source tracking, the CCD cameras record images which are analysed offline using software tools including Astrometry.net to determine the true pointing coordinates.

astro-ph.IM↗