Localization plays a pivotal role in numerous military and commercial applications, including homeland security, electronic warfare, and intelligent control, guidance, and navigation systems. This paper investigates passive localization of Wi-Fi network users employing the Time Difference of Arrival (TDOA) method. Real-world radio signals were acquired using USRP N210 devices for evaluating the system's performance in practical environments. This paper presents a method to improve localization accuracy by correcting sampling time errors and interpolating sampling points, addressing discrepancies in receiver sampling rates. Accurate synchronization between receivers is achieved by implementing a multi-stage synchronization algorithm. The user's position was calculated with a mean error of 3.62 meters using the LS method and 1.52 meters using intersection averaging. Simulation results demonstrate that the proposed method holds significant potential for application in wireless network-based localization systems. Compared to similar systems, this system significantly reduces costs and can passively track users without interfering with existing Wi-Fi infrastructure, making it an attractive option for security applications.