Analog Front-End: Circuit of Pulsar-Based Timing Synchronization for the WAMS

The front-end circuit used in the pulsar acquisition of the radio telescope determines the availability of the entire pulsar-based timing framework. However, it would be expensive and resource consuming to use a real radio telescope in the circuit design process. To address this issue, in this article, the hardware-in-the-loop simulation solution is proposed to generate, sample, and extract pulse signals in real time. The artificial pulse generation method is first proposed to generate the pulses that are close to real pulsar signals. Then, three analog front-end circuit architectures (AFCAs) are proposed to generate the analog pulses, including the superposition, attenuator, and attenuator-based superposition structures. The generated pulses are close to the real pulsar signal in shape, amplitude, and noise level. Next, a pulsar-based timing synchronization framework that can be used to improve the timing accuracy of the wide-area monitoring systems is developed to process the sampled data. Multiple experiments are conducted to verify the effectiveness of the analog front-end and the pulsar-based timing synchronization framework using the simulated pulse and real pulsar signals. The results demonstrated that the designed AFCAs can generate effective analog pulses, and is convenient and flexible.