海底大地电磁探测的实时数据备份技术

海洋环境复杂.国外的文献和国内的应用例子均表明, 电磁探测仪器在海底工作时, 由于各种不测因素导致数据丢失的现象时有发生.相对于陆上同类测量而言, 海底大地电磁探测成本高, 作业难度大, 且不易实施数据采集的重复观测.因此, 实时数据备份技术的研发, 对确保实测数据的完整性, 从而提取探测区域的全部介质电性信息, 将具有重要的科学意义.在所确定的技术方案中, 以PC104计算机为主控单元, 自主开发ISA总线转USB总线的接口电路, 实现将海底采集的大地电磁数据实时地同时存入IDE盘和U盘.电路采用了CPLD译码及逻辑控制、双向数据收发及CH375A接口转换等芯片, 并在PC104源程序中扩展了对上述芯片的控制指令.仪器具备了实时数据备份的功能后, 以冗余的数存量确保了海底大地电磁信息的完整保存.经黄海海试, 证实了本技术的实用效果. 

The Technique for Memorizing Acquisition Data Doubly and Simultaneously on the Marine Magnetotellurics

The marine environment is complex. Both the overseas literatures and the domestic applications indicate that when the detecting device is working on the seafloor, losing the data occasionally happens because of various unexpected factors. Compared with continental operation, there are higher risk and expenses in detecting and more difficult in acquisition repeatedly on the marine magnetotellurics. Therefore, it is of great scientific significance to study the technique prospecting doubly and simultaneously so as to extract the whole medium electric information in exploration areas and ensure the integrality of the real acquisition data. The project chooses the PC104 computer as microcontroller and also comprises of the interface circuit, which converts the PC104 bus to the USB bus and saves the real time data acquired on the marine magnetotellurics into the IDE disk and U disk simultaneously. The chips adopted by the circuit include CPLD in encoding and logic controlling, bidirectional data received and transmitted and CH375A of interface conversion, and the source program of PC104 also contains their corresponding instructions. With that function, it has insured the full preservation of the acquisition because of redundant data. The practicality has been approved by Huanghai Sea experimentation.