Abstract: A system for determining the time between the receipt of two different sils, includes a voltage ramp generator which generates a time dependent voltage signal upon receipt of a timing pulse at a time T.sub.1, and provides the instantaneous value of the voltage signal when the voltage ramp generator receives an input signal having a predetermined threshold value at time T.sub.2. A data processor coupled to receive the voltage signal, generates the timing pulse, and determines a time difference .DELTA.T from the voltage signal, where .DELTA.T=T.sub.2 -T.sub.1.

Abstract: A buoyed sensor array communications system comprises multiple sensor syss electrically connected to a signal transmission line which are positioned at predetermined locations along the signal transmission line to form a linear sensor array. Each of the sensor systems generates a data signal in response to receiving an address signal. The system further includes; a processor system electrically connected to the signal transmission line for transmitting address signals to enable any one of the sensor systems at a time in a selectively accessed order and has a data storage memory for storing the data signal from each of the sensor systems as stored data. A radio frequency transmitting system is coupled to the data processor and transmits the stored data at a predetermined time. A negatively buoyant structure connected to the signal transmission line pulls the communications system to the bottom of a body of water upon deployment.

Abstract: A buoyed sensor array communications system comprises multiple sensor syss electrically connected to a signal transmission line which are positioned at predetermined locations along the signal transmission line to form a linear sensor array. Each of the sensor systems generates a data signal in response to receiving an address signal. The system further includes; a processor system electrically connected to the signal transmission line for transmitting address signals to enable any one of the sensor systems at a time in a selectively accessed order and has a data storage memory for storing the data signal from each of the sensor systems as stored data. A radio frequency transmitting system is coupled to the data processor and transmits the stored data at a predetermined time. A negatively buoyant structure connected to the signal transmission line pulls the communications system to the bottom of a body of water upon deployment.