Abstract: A Wireless Slide Fence utilizing signal reflection technology to detect rockslides and can determine the size and location of fallen rocks/objects impeding travel along a train track is presented. The present disclosure solves the technological problem of determining rock size and location to validate rockslide/fall alarms to reduce false alarms, while minimizing repairs required by conventional systems through the use of obstacle detection units and vital logic controllers. The present disclosure improves the performance of the system by, generating validated alarms when fallen rocks/objects satisfy the size criteria and are located in an area hazardous to train operations. In one exemplary embodiment, a loitering time can be implemented to validate object detections to reduce false positives due to transient objects such as migrating animals.