I recently received a challenge to determine the depth of a trench where an electrical cable needs to be laid down by a telecommunication company. The company wants to ascertain the depth using LIDAR data from an iPhone 15. Despite my efforts to find relevant papers on this topic, I haven’t had any luck. Could you please provide some ideas on how to make this possible?
I am not an expert on iPhone LiDAR, but I work with airborne LiDAR in my job. I hope to be helpful by providing some ideas and preprocessing the data you may need for your work.
I will proceed under the assumption that you only have LiDAR data at hand.
For preprocessing:
Check coordinates
Georeference
Clean noise
Classify ground and non-ground objects (like buildings, vegetation, etc.)
A particularly important aspect of preprocessing is determining the ground elevation.
For the main method, I suggest two idea:
Idea 1: Raster-Based Approach
Convert LiDAR data to DSM (Digital Surface Model) in GeoTIFF format.
Perform detection or segmentation for the trench.
Calculate the difference between ground elevation and trench elevation.
Note: DSM is a 1-band image where each pixel represents elevation. You can use any image processing technique on it.
Idea 2: Point Cloud-Based Approach
Segment the trench bottom surface. All supervised, unsupervised learning, and rule-based methods are worth trying.
Calculate the difference between ground elevation and trench elevation.
If you plan to use machine learning for point cloud data (LiDAR), please check out ‘part segmentation’ for point clouds. I believe it is similar to your task.
I apologize for my limited English skills.
Hope all of your business will be successful.