Low-Frequency Observation of Taurus-A with Signal Processing Techniques in Passive Mode Operation of CU-ST Radar

Calcutta University Stratosphere Troposphere Radar is a Pulse Doppler Active Phased Array of 473 Yagi-Uda Antennas at central frequency of 53 MHZ with a bandwidth of 8 MHz, arranged almost as a circular array. The facility under the University of Calcutta is located in Kalyani, West Bengal, India. It is a monostatic radar, devised to work primarily in active mode in atmospheric, ionospheric, and weather studies. And passive mode operation though supported by the system, involved various signal processing techniques and plotting methods. Passive mode is very lucrative considering no power being transmitted which reduces operational costs for Active Arrays. This paper outlines the steps involved in the radar operation and data processing in passive mode observation of astronomical source Taurus-A (see Table. 1), also known as 3C 144 or the Crab Nebula, on 18th April, 2023. It serves as a proof of concept as well as serves to understand its beam pointing accuracy and beam pattern.