爆炸地震深部探测的模拟磁带记录系统

为了进行西藏高原地区的爆炸地震研究,研制了一套模拟磁带记录系统。每台仪器包括三个两周的拾震器（LS-1型）、三个相应的低噪声线性放大器（DDF-5型）、三个调制器、一台低频磁带记录器（DCJ-1型）、石英钟、对时器和收音机。仪器频率范围是2周-20周（对速度）,时间误差小于0.1秒。采用抖动补偿和频率滤波的办法,使系统的信噪比提高到50分贝。系统的幅度误差小于10％。经过野外实地观测和资料整理分析,证明其性能和指标能够满足地壳与上地幔爆炸地震研究的需要。通过模/数转换器,把模拟磁带转录成数字磁带,可以在电子计算机上进行各种数字处理。

A MAGNETIC TAPE RECORDING SYSTEM FOR DEEP EXPLOSION SEISMIC SOUNDING

In order to study the structure of the crust and the upper mantle in the Xizang plateau, we have developed a set of analog magnetic tape recording system. Each seismograph consists of three 2Hz seismometers of type LS-1, three amplifiers of type DDF-5, three modulators and one magnetic tape recorder of type DCJ-1, a quartz clock, a timing circuit and a radio.The frequency band of the seismograph is 2Hz to 20Hz. Time error is less than 0.1 second. Being improved by the flutter compensation and filtering techniques, the S/N radio of the system is about 50 db. The amplitude error of the system is less than 10%.The field operation and the data analysis proved that this instrument could meet the needs for deep explosion seismic sounding. The analog tape can be converted to digital magnetic tape by using an A/D converter, and then data processing can be done on computer.