This thesis reports on recent advances made in real-time intruder detection for an intrusion system developed at Texas A&M University that utilizes a phase-sensitive optical time-domain reflectometer. The system uses light pulses from a highly coherent laser to interrogate a length of buried optical fiber. The Rayleigh backscattered light is detected, and a FPGA-based system is used to implement real-time signal processing algorithms. With the introduction of real-time signal processing, the system can run continuously, only triggering intrusions when they are detected. These recent advances allow for more effective processing of intruder signatures, while still giving results comparable to previous off-line signal processing results. With these advances, this technology is a prime candidate for low-cost perimeter monitoring of high-value and high-security targets, such as nuclear power plants, military bases, and national borders