On the modern battlefield, Global Positioning System (GPS) can be unreliable in contested environments due to jamming or signal loss. Existing alternatives like high-accuracy inertial navigation systems (INS) are prone to higher drifts over distances with platform dependent performance, while solutions like Visual-Inertial Odometry (VIO) and Lidar-Inertial Odometry (LIO) lack accuracy and robustness on challenging terrain. We present a novel Positioning, Navigation, and Timing (PNT) solution that overcomes these limitations. It integrates inertial measurements from an IMU and doppler measurements from a Frequency Modulated Continuous Wave (FMCW) LiDAR within a non-linear filtering framework to robustly measure motion states that achieve up to 0.1% Cross Track Error (CTE) rate in real-time. Furthermore, unlike solutions reliant on wheel speed sensors, our method requires no platform-specific information and is resilient to environmental factors such as wheel-slip, dynamic lighting, and weather conditions. This makes it highly portable, scalable, dependable, and readily deployable on a diverse set of platforms like ground vehicles, low-altitude drones, and even dismounted soldiers. Compared to traditional Time-of-Flight (ToF) LiDAR systems that operate in the Near Infrared (NIR) spectrum, FMCW LiDARs offer lower detectability due to their operation at lower peak power and within the Short-wave Infrared (SWIR) spectrum. In the face of increasing GPS disruptions and the proliferation of autonomy in military applications, our method provides a dependable solution for Positioning, Navigation, and Timing (PNT) in a broad variety of challenging scenarios.