基于短时1.5维谱的脉冲星个别脉冲检测

Detection of Pulsar Individual Pulse Based on Short-Time 1.5 Spectrum

为改善脉冲星微弱脉冲信号的检测性能,分析了个别脉冲及其背景噪声1.5维谱特征,以脉冲星辐射脉冲谱能量与噪声谱能量的比值作为脉冲星辐射脉冲出现的判据,以1.5维谱的短时设计反映判据发展的时变特性,提出了基于短时1.5维谱的脉冲星个别脉冲检测算法。对PSR J1056-6258等多颗脉冲星观测数据进行了实验,结果表明基于短时1.5维谱的脉冲星个别脉冲检测的可检测信噪比可达到约-26d B,且大于30%的色散预修正即可保证低信噪比情况下射电脉冲星色散脉冲信号的检测性能。

In order to improve the detection performance of pulsar weak individual pulse, the characteristics of 1.5 spectrum of pulsar individual pulse and its background noise are analyzed respectively, then the technology of pulsar individual pulse detection from background noise based on short-time 1.5 spectrum is presented, whose criterion is the ratio of the peak value of between individual pulse spectrum and the average of background noise spectrum. Short-time spectrum window is designed in order to reflect the change of the criterion with time. The experiments on the datum of a few pulsars, such as PSR J1056-6258, show that pulsar individual pulse can be detected from its background noise effectively by using short-time 1.5 spectrum, and the detection performance can be assured by prededispersion partly.