Disclosed are buried cable protection systems and methods that employ impulse signal detection by optical fiber sensing technologies, and which provide such protection automatically and in real-time. The methods theoretically model a time difference of arrival (TDoA) of an impulse wave travelling to a DFOS sensor fiber cable. A model employing a set of propagation relationships that account for vague knowledge about wave propagation speed and threat range(s) is fitted with parameters based on a numerical simulation—without specific knowledge of a source of vibration. As compared to vibration magnitude information, time of arrival (ToA) information is more consistent and less sensitive to ambiguities and inaccuracies. In addition, the model parameter can be adjusted adaptively when temporal resolution of the sensor changes or fluctuates. As a result, our inventive systems and methods effectively detect impulse signals from machines or other activities generating vibratory impulse ground events at different distances to a fiber optic cable and distinguish same from background noises including those caused by transportation modes such as train or vehicular traffic.