A method of calibrating a radar-based vibration sensor that includes a radar head coupled to a vibration device includes disposing the vibration sensor at a fixed distance from a target, and transmitting radio frequency (RF) signals toward, and receiving RF signals reflected by, the target. An excitation voltage is supplied, at a plurality of different excitation frequencies, to the vibration device to cause the vibration sensor to vibrate. Vibration sensor acceleration is determined at each of the different excitation frequencies. A calibration curve is generated based on the determined vibration sensor acceleration at each of the different excitation frequencies, and on the reflected RF signals at each of the different excitation frequencies.