Snow / water level detection with distributed acoustic sensing integrated ultrasonic device

A distributed fiber optic sensing (DFOS) system comprising:

• a length of optical sensor fiber;
• a DFOS interrogator that generates optical pulses at one or more frequencies, introduces the generated pulses into the length of optical sensor fiber, receives backscattered signals from the length of optical sensor fiber, and determines from the backscattered signals acoustic/vibrational activity occurring at one or more points along the length of the optical sensor fiber;
• an ultrasonic transducer positioned at a location along the length of the optical sensor fiber, said ultrasonic transducer positioned above ground level, and configured to:
• determine a baseline distance between the ultrasonic transducer and the ground;
• determine a measured distance between the ultrasonic transducer and the ground;
• determine a snow/water level from a difference between the baseline distance and the measured distance;
• and
• encode the snow/water level into a vibration pattern that is mechanically produced by the ultrasonic transducer, the mechanical vibration pattern producing mechanical vibrations in the length of optical sensor fiber for detection by the DFOS interrogator;
• wherein said DFOS interrogator is further configured to determine the snow/water level from the backscattered acoustic signals;
• wherein the DFOS interrogator is further configured to determine a location along the length of the optical sensor fiber at which the snow/water level is determined;
• wherein the snow/water level is mapped to a vibration pattern in a one-to-one manner;
• wherein the vibration pattern exhibits a center frequency and a duration;
• and
• wherein the snow/water level is represented as a series of digits, wherein a ones digit of the snow/water level is D1, and the frequency of the vibration pattern F, is represented by:
• F=400 Hz+D1*50 Hz.