Development of the Plate Antenna and Research for ELF EMW at Deep Sea Bed

我们成功地研制了用于深海床的平板天线，并获得了有关海底电环境的信息。该平板天线系统由两块20 cm×20 cm×1 mm的不锈钢平板和幅度为2×10~(-4)的放大电路和用于数据记录的DAT组成。采用FWT(第一小波变换)方法时，系统在海面上的最小可检测幅度为0.1微伏。因此，如果我们使用带织机跨度的平板天线，最小可探测电压将是10 nV。由于浮动装置(TR6000，Benthos Inc.)的故障，在浅海底而不是深海海底进行观测，深度超过100米。在美国海湾附近50m处观测到的电场小于+-10.5微伏，这是由电路噪声控制的。通过与球状天线在陆地上和在深度20m处测量的电磁脉冲的数据进行比较，我们发现，在距离美国海岸5.47公里的50m深度处，该系统可以探测到相当于海水20m厚的分段层下的脉冲，并且估计了商业交流信号的幅度为+-63nV/m。

We succeeded to develop the plate antenna for the deep sea bed and obtained information on the electrical environment at the sea bed. The plate antenna system consist of two stainless steal plates of 20cm X 20cm X 1mm and the amplifier circuit with a gain of 2X10^4 in amplitude and the DAT for the data recording housed in a glass sphere. The performed minimum detectable amplitude of the system is 0.1 micro-Volts in the sea when we utilize the FWT (First Wavelet Transfer) method. So if we use the plate antenna with lOOm span, the minimum detectable voltage will be 10 nV.Due to the trouble of the floating device (Model TR6000, Benthos Inc), observation performed at the shallow sea bed instead of the deep sea bottom, more than lOOOm in depth. The observed electric field at depth 50m, near Usa bay is less than +- 10.5 micro volts which is governed by circuit noises.Comparison with the data of the EM pulses on land measured by the ball antenna and in the sea at depth 20m, we showed that the pulses under the segment layer of a thickness of 20m equivalent of sea water, can be detected with the present system in the case of their amplitude more than 100 mV.Moreover, we estimated the amplitude of the commercial AC signals at the 50m depth, at 5.47 km away from the Usa sea shore, as +-63 nV/m.