Tree height measurement with smartphone embedded sensors

This paper proposed a tree height estimation method using light detection and ranging (LiDAR) and red, green, blue (RGB), and inertial measurement unit (IMU) sensors on an iPhone. The method scans the trunk, adaptively selects the key frames, reconstructs the 3D map via visual SLAM together with LiDAR and camera intrinsic parameters. Tree height is estimated by computing the distance between the selected point at the base and any point of interest on the trunk. Experiments show that the proposed method can measure tree height with bias values of 0.199, 0.016, –0.173, and 0.029 feet, RMSE values of 0.415, 0.404, 0.727, and 0.922 feet, and maximum absolute errors of 0.869, 0.878, 1.870, and 2.770 feet for target heights of 8, 12, 16, and 20 feet, respectively.