New progress of ocean bottom electromagnetic receiver
WANG Hai-Feng1,2, DENG Ming1,2, CHEN Kai1,2
1. School of geophysics and information technology, China University of Geosciences, Beijing 100083, China;
2. Key Laboratory of Geo-detection Ministry of Education, China University of Geosciences, Beijing 100083, China
The marine electromagnetic method has been widely used in physical oceanography, geophysics and underwater target detection. These applications should be based on high precision electromagnetic signal observation in the marine environment. The ocean bottom electromagnetic receiver designed for high precise ocean bottom electromagnetic observation should overcome some technical problems such as high reliable release and recovery, high stable underwater operation, low noise level, high dynamic range, and low time drift. The research experience and results as well as the latest developments of ocean bottom electromagnetic receiver from China University of Geosciences (Beijing) were reported in this paper. The new ocean bottom electromagnetic receiver's indicators are as follows:typical E-field noise:0.1 nV/m/√Hz@0.5 Hz; dynamic range:higher than 110 dB; clock drift:lower than 5 ms/day, in line with advanced receivers of other countries. By early 2016, ocean bottom electromagnetic data acquisitions on about 60 sites had been completed. Since 2012, the receiver's recovery rate has reached 100%. A lot of high-quality ocean bottom magnetotelluric data as well as controlled-source electromagnetic data were obtained by these receivers, which have been successfully used in oil-gas and hydrate explorations.