SARAS: a precision system for measurement of the Cosmic Radio Background and signatures from the Epoch of Reionization

Understand

SARAS is a correlation spectrometer purpose designed for precision measurements of the cosmic radio background and faint features in the sky spectrum at long wavelengths that arise from redshifted 21-cm from gas in the reionization epoch.

• SARAS operates in the octave band 87.5-175 MHz.
• We present herein the system design arguing for a complex correlation spectrometer concept.
• The SARAS design concept provides a differential measurement between the antenna temperature and that of an internal reference termination, with measurements in switched system states allowing for cancellation of additive contaminants from a large part of the signal flow path including the digital spectrometer.