BSA LPI Radio Telescope

The BSA is a meridian instrument, and is one of the most sensitive radio telescopes operating at meter wavelengths. Starting in 2000, the operating frequency range of this instrument has been 111 MHz ± 1.25 MHz. The fluctuational sensitivity of the radio telescope in a 2.5 MHz bandwidth with a time resolution of 0.1 s is 140 mJy. The signal is registered using a multichannel digital receiver that enables the signal to be recorded in two modes. The first recording mode has relatively low frequency resolution of six frequency channels, each with a receiver bandwidth of 415 kHz. The time interval between readouts is 100 ms. The data obtained in this mode are used to continuously monitor scintillating sources. The second recording mode uses 32 frequency channels with a bandwidth of 78 kHz and a time resolution of 12.5 ms. In both modes, the signals are digitally processed using a 512-sample FFT processor. In our current study, we used data recorded with a time resolution of 100 ms. To study large numbers of interplanetary scintillations of compact radio sources in a monitoring regime, a stationary, 96-beam antenna beam was created, which covers the sky from −9 to 42 degrees in declination. The full width at half-maximum of an individual beam depends on the declination of the observed source, and ranges from 24' to 48'. The time for the passage of a source through the antenna beam is 4–7 min. The maximum effective area of the antenna (47 000 square meters) is realized at the zenith, and decreases toward the horizon as cos z, where z is the zenith angle. The system noise temperature fluctuates in the range 550–3500 K, depending on the sky background. An advantage of the BSA for searching for signals similar to FRBs is its large field of view (about 50 square degrees), and also its continuous and round-the-clock monitoring of the sky, with recording of data on a server for subsequent reduction.