OCRA (ang. One Centimeter Receiver Array) is a set of differential, 30-GHz, broadband receivers, installed in the focal plane of the 32-m radio telescope. OCRA-p is a two-beam prototype system available since winter 2004, and OCRA-F is an 8-beam array, installed in December 2009. For an assumed noise level using multi-beam systems enables to map any given patch of the sky with less observational time. The two receivers were built at the University of Manchester, although some of the system components (such as parts of back-end modules, absorber as well as data acquisition and control software) were developed in Toruń Centre for Astronomy of the Nicolaus Copernicus University. The parameters and operation scheme of the receivers were described in details in two PhD theses (“Simulations and Observations of the Microwave Universe“, and “The One Centimeter Receiver Array Prototype – Evaluation, Operation and future steps”).
OCRA was used in a number of scientific projects. Since 2016 is it mostly used to observe Sunyaev–Zel’dovich effects in selected galaxy clusters.
- “OCRA calibrations” – B. Lew (2016/1, local access)
- “OCRA-SZ – user’s reference (PL)” – B. Lew (2016, local access)
Bartosz Lew, PhD