Invention relates to a novel method of and
system for
ranging between an acoustic source carried on an unmanned or autonomous undersea
mobile vehicle (UUV or AUV) and preferably a plurality of
hydrophone receivers remotely deployed from the vehicle in predetermined patterns, generally suspended from sonobuoys equipped with above-the-sea
relay radio transmitting antennas, and with
time synchronization provided amongst the source and the receivers, wherein the time
delay from the transmissions of the source is measured by utilizing special
signal processing, enabling range to be measured in close to real time by determining the product of the sound velocity and the measured time
delay, and with the process continually and periodically being repeated throughout the duration of the vehicle run. Given the range, the
system may then be used to measure the acoustical properties of and / or
receiver system performance in the sea or other
water body, such as transmission or propagation loss TL,
channel impulse response, bottom geoacoustic properties,
source level,
receiver sensitivity calibration,
sonar operator readiness and
sonar receiver performance and the like. Further, in situ measured data can be assimilated with models to enable more accurate prediction of the
ocean environment than could be obtained from either individually.