Abstract: A continuously oscillating cantilevered beam having a velocity transducer that produces a preferably voltage signal as a function of the beam's velocity. An amplifier receives the signal and amplifies accordingly to produce an amplified signal that varies as a function of the beam's velocity. The amplified signal powers an electromagnet that is disposed in close proximity to a magnet on the beam. The resulting apparatus is a system that is driven cyclically by a force that is essentially generated in proportion to, and then amplified, the velocity of the beam itself. This ensures that the timing of applying the driving force is precisely synchronized with the movement of the beam.

Abstract: In accordance with the present invention, a marine streamer test system and method (MARSTEST) is disclosed for testing field-worthiness of hydrophone sections within the streamer under both passive and dynamic operating conditions. With regard to a passive operating state, five (5) test parameters are automatically generated and compared with upper and lower limits stored within a mini-computer housed aboard the marine exploration boat. Any out-of-specification values trip an alarm network and a printer to warn of the malfunctioning streamer section. Result: replacement or other repair can be effected. With regard to dynamic operating conditions, acceptable "signature" characteristics of the streamer (such characteristics can be 2 or more of the above 5 parameters) are stored within the computer aboard the exploration boat and are compared with actually generated field parameter values acquired during operations, say between "shots", i.e.