| 摘要 |
The level of signal noise caused by fluid flow at a pressure transducer, such as a hydrophone or geophone, is determined by measuring the electric field induced when the fluid flows through a magnetic field B. The electric field, which is proportional to flow rate, is measured by electrodes 4a-d positioned about the transducer. The pressure due to the flow is derived from the flow rate voltage by a digital filter which may be adaptive, to allow for varying flow conditions, or which may employ a predetermined electric field/flow noise relation. This flow noise is then subtracted from the received signal, the resultant signal then being substantially noise free. <IMAGE> |
