| 摘要 |
<p>An electronic filter for use in determining the position of a body travelling through water relative to a datum such as mean sea level, and having specific application to underwater seismic systems that produce profiles of the terrain beneath bodies of water. The filter is connected to an accelerometer and a pressure transducer, physically located within the body, that respectively produce an acceleration signal indicative of the body's vertical acceleration and a pressure signal indicative of the body's vertical displacement with respect to the datum. The filter combines the acceleration and pressure signals to effectively isolate a signal proportional to noise generated by the pressure transducer. The filter then combines the signal so isolated with the pressure transducer signal to produce a vertical displacement signal relatively free from noise. The filter is used in association with apparatus that produces a correction signal that approximates accelerometer signal components corresponding to the effect of gravity on the accelerometer. The filter combines the correction signal with the acceleration signal to attenuate noise components in the filter output signal that correspond to the gravity effects.</p> |
