Radio Interferometer Sensitivities for Three Types of Receiving Systems: DSB, SSB, and 2SB Systems

The purpose of this paper is to study the detection sensitivity suitable to the practical situation for a radio interferometer. For the radio interferometer, the three types of receiving systems are a double-sideband (DSB), a single-sideband (SSB), and a two-single-sideband (2SB) systems. The evaluation of these receiving systems is of significance to explore the best performance for a radio interferometer. In this paper, the signal-to-noise ratios of these three-type receiving systems are newly derived to investigate the performance and key features of each system. We demonstrate the system noise temperatures of SSB, 2SB, and DSB receiving systems by using the ALMA-specification receiver noise temperature and the atmosphere condition measured at the ALMA site, and present the relative sensitivities between the 2SB and DSB receiving systems at the ALMA site. From these results, we recommend the 2SB receiving system for all bands of ALMA.