Improved processing of sensor data (e.g., LiDAR data) can be used to distinguish between free space and objects/hazards. Autonomous vehicles can use such information for performing autonomous driving and/or parking operations. LiDAR data can include a plurality of range measurements (e.g., forming a 3D point cloud). Each of the range measurements can correspond to a respective LiDAR channel and azimuth angle. The processing of LiDAR data can include identifying one or more paths as candidate ground paths based on one or more path criteria. The processing of LiDAR data can also include identifying one or more of the plurality of range measurements as ground points or non-ground points based on the one or more paths identified as candidate ground paths and based on one or more point criteria.