Abstract: A low flow noise sonobuoy suspension system having a surface float, a sussion cable having a compliant portion, a bridle, a hydrophone, a mechanical cable, a terminal weight, and a drogue. The hydrophone is located within the bridle and is attached to the bridle so as to allow the hydrophone to remain roughly vertical if the bridle is tilted. The bridle is located below the surface float and is connected to the surface float by means of the suspension cable. The drogue is located below the bridle and is connected to the bridle by a mechanical cable. The drogue is connected at an attachment point on the mechanical cable such that the relative velocity of the hydrophone is negligible. The terminal weight is also attached to the mechanical cable. By means of this arrangement, both the horizontal motion noise caused by the relative velocity of the hydrophone, and the vertical motion noise caused by the surface waves are reduced.

Abstract: A deep ocean recoverable, tethered acoustic sensor system launchable from aircraft or ship. Upon water entry, the system separates into an upper flotation module containing a receiver/transmitter, antenna and inflatable bag, and a lower flotation module containing an expandable hydrophone array, transmission cable, flotation chamber, cable disconnect means, radio transmitter and antenna, and a flashing beacon light. The lower flotation module also includes a releasable anchor assembly containing a tethering cable. Recovery of the lower flotation module is accomplished by actuation of the cable disconnect means either by a preset timer means contained within the flotation module or by remote electrical command; upon cable disconnect, the anchor assembly and upper flotation module are discarded, and the lower flotation module floats to the surface for recovery.