Unmanned ground systems equipped with sensors, such as cameras, radar, and LiDAR, play a crucial role in detecting environmental conditions. Specifically, recognizing drivable areas in uneven terrain is essential in establishing stable navigation plans. Information on the oncoming road's height profile and roughness obtained from LiDAR sensors will help ensure safe navigation and effective control planning. This study introduces a real-time, LiDAR-based approaching road height profile and a roughness estimation system in perceiving unstructured outdoor environments. Considering the mechanical characteristics of the system, the proposed method estimates the driving path, and generates a road height profile by using LiDAR point clouds. Finally, we will be analyzing road roughness in the frequency domain, and will be classifying roughness based on the ISO 8608:2016 standard. Real-world experiments conducted in both off-road and on-road environments demonstrate the feasibility and effectiveness of the proposed system in estimating terrain roughness in real time