Share Email Print
cover

Proceedings Paper

Thermal behavior of the Medicina 32-meter radio telescope
Author(s): Tonino Pisanu; Franco Buffa; Marco Morsiani; Claudio Pernechele; Sergio Poppi
Format Member Price Non-Member Price
PDF $14.40 $18.00

Paper Abstract

We studied the thermal effects on the 32 m diameter radio-telescope managed by the Institute of Radio Astronomy (IRA), Medicina, Bologna, Italy. The preliminary results show that thermal gradients deteriorate the pointing performance of the antenna. Data has been collected by using: a) two inclinometers mounted near the elevation bearing and on the central part of the alidade structure; b) a non contact laser alignment optical system capable of measuring the secondary mirror position; c) twenty thermal sensors mounted on the alidade trusses. Two series of measurements were made, the first series was performed by placing the antenna in stow position, the second series was performed while tracking a circumpolar astronomical source. When the antenna was in stow position we observed a strong correlation between the inclinometer measurements and the differential temperature. The latter was measured with the sensors located on the South and North sides of the alidade, thus indicating that the inclinometers track well the thermal deformation of the alidade. When the antenna pointed at the source we measured: pointing errors, the inclination of the alidade, the temperature of the alidade components and the subreflector position. The pointing errors measured on-source were 15-20 arcsec greater than those measured with the inclinometer.

Paper Details

Date Published: 23 July 2010
PDF: 9 pages
Proc. SPIE 7739, Modern Technologies in Space- and Ground-based Telescopes and Instrumentation, 773935 (23 July 2010); doi: 10.1117/12.857422
Show Author Affiliations
Tonino Pisanu, National Institute for Astrophysics, Cagliari Astronomical Observatory (Italy)
Franco Buffa, National Institute for Astrophysics, Cagliari Astronomical Observatory (Italy)
Marco Morsiani, National Institute for Astrophysics, Institute of Radio Astronomy (Italy)
Claudio Pernechele, National Institute for Astrophysics, Cagliari Astronomical Observatory (Italy)
Sergio Poppi, National Institute for Astrophysics, Cagliari Astronomical Observatory (Italy)


Published in SPIE Proceedings Vol. 7739:
Modern Technologies in Space- and Ground-based Telescopes and Instrumentation
Eli Atad-Ettedgui; Dietrich Lemke, Editor(s)

© SPIE. Terms of Use
Back to Top