Pulsar Emission Recorders of Low-Frequency Radio Telescopes at the PRAO ASC LPI

Abstract

Digital pulsar emission recorders (PER) for the BSA and DKR-1000 radio telescopes of the PRAO ASC LPI are described. The signal of the operating band of the radio telescope is transferred to the range 0‒2.5 MHz using a down converter, digitized using an analog-to-digital converter (ADC) and processed by PER hardware. All further processing (spectral analysis, accumulation of power spectra to a given time resolution, data binding to the pulsar period, control of data transfer for recording to a hard disk) is performed using field programmable gate arrays (FPGAs) of the recorder. In addition to the modes with signal processing by the drive’s circuit resources, a recording mode has been introduced directly from the ADC, followed by recording the ADC sample stream to the hard disk. For this mode, an example is given of obtaining pulsar B1133+16 profiles with different time resolutions of 1.024 milliseconds and 51.2 microseconds using the same data for processing.