提高光栅数字地震检波器精度的方法研究

Study on Method of Improving Digital Grating Geophone Precision

在地震勘探系统中,随着数据记录系统动态范围的突破,地震检波器的动态范围已不能满足系统的要求,提高检波器的精度和动态范围变成地震勘探技术研究的关键。光栅数字地震检波器的研制成功,提高了检波器的精度和动态范围。通过对光栅传感器机理的深入分析,采用5细分专用芯片为核心的细分电路,成功实现了光栅脉冲信号的20倍细分技术。在采用100线计量光栅的情况下,使检波器分辨率达到0.000 5 mm,动态范围达到75 dB。并采用PIC单片机系统完成了振动信号的再现。该方法将有助于光栅数字地震检波器的性能完善,为实现高精度地震勘探技术奠定基础。

Along with break through dynamic range of the data recording system, the geophone can＇ t satisfy demands of it, then enhancing precision and dynamic range of the geophone becomes key point of the seismic technique. The development of grating digital geophone enhances geophone precision and dynamic range. Through analyzing the grating sensor mechanism and adopting programmable voltage-regulator tube as core of the subdivision circuit, the grating pulsing signal with 20 times subdivision is realized. Geophone resolution ratio reaches to 0.0005mm and dynamic range reaches to 75dB by adopting 100 line/mm measuring grating. Meanwhile, the reappearance of the vibration signal is realized with PIC microcontroller. The method will conduce to perfect function of the grating digital geophone and establish foundation of high precision seismic technique.