Mitigation of Pulsed Interference to Redshifted H I and OH Observations between 960 and 1215 Megahertz
Mitigation of Pulsed Interference to Redshifted H I and OH Observations between 960 and 1215 Megahertz
复制标题
减轻 960 至 1215 兆赫之间红移 H I 和 OH 观测的脉冲干扰
DOI：
--
复制
发表时间：
2005
期刊：
影响因子：
--
通讯作者：
R. Bradley
中科院分区：
文献类型：
--
作者：
J. Fisher;Qing Zhang;Yibin Zheng;S. G. Wilson;R. Bradley
中性氢的21厘米谱线(1420.4兆赫)和羟基分子的四条18厘米谱线(1612-1720兆赫)的红移是可以观察到的，这使得它们的测量线频远远低于它们受保护的频带。部分红移范围(HI的z=0.171-0.477，OH的z=0.37-0.73)落在分配给飞机导航的960至1215兆赫兹频段内。该频段中的大多数信号都是低占空比的脉冲发射，因此脉冲之间的大部分时间是无干扰的。本文概述了该频段信号的结构和测量特性，并演示了一种有效的信号处理策略，该策略可以有效地从光谱中去除具有数小时积分所产生的灵敏度的脉冲信号。
The neutral hydrogen 21 cm spectral line (1420.4 MHz) and the four 18 cm lines of the hydroxyl molecule (1612–1720 MHz) are observable at redshifts that put their measured line frequencies well below their protected frequency bands. Part of the redshift ranges (z = 0.171–0.477 for H I and z = 0.37–0.73 for OH) fall in the 960 to 1215 MHz band that is allocated to aircraft navigation. Most of the signals in this band are pulsed emissions of low duty cycle so much of the time between pulses is interference-free. This paper outlines the structure and measured properties of signals in this band and demonstrates a signal processing strategy that is effective at removing the pulsed signals from spectra at sensitivities produced by several hours of integration.