摘要
A multi-function digital baseband data acquisition system is designed for the sampling,distribution and recording of wide-band multi-channel astronomical signals.The system hires a SNAP2board as a digital baseband converter to digitize,channelize and packetize the received signal.It can be configured dynamically from a single channel to eight channels with a maximum bandwidth of 4096 MHz.Eight parallel HASHPIPE instances run on four servers,each carrying two NVMe SSD cards,achieving a total continuous write rate of 8 GB s^(-1).Data are recorded in the standard VDIF file format.The system is deployed on a 25-meter radio telescope to verify its functionality based on pulsar observations.Our results indicate that during the 30-minute observation period,the system achieved zero data loss at a data recording rate of 1 GB s^(-1) on a single server.The system will serve as a verification platform for testing the functions of the QTT(Qi Tai radio Telescope)digital backend system.In addition,it can be used as a baseband/VLBI(Very Long Baseline Interferometry)recorder or D-F-engine of correlator/beamformer as well.
基金
funded by the National Natural Science Foundation of China(NSFC,Nos.12073066,61931002 and 12073067)
the Youth Innovation Promotion Association of Chinese Academy of Sciences(CAS,No.2020063)
partly supported by the Operation,Maintenance and Upgrading Fund for Astronomical Telescopes and Facility Instruments,budgeted from the Ministry of Finance of China(MOF)and administrated by the CAS。
