The Caveatron has interchangeable LIDAR modules to support scanning different sizes of passages and to provide options for the cost of the LIDAR, which is the most expensive component of the system. At the present time, two LIDAR module types are supported – a 4 m range LIDAR and a 25 m range LIDAR. Plans are in the works to support a third module type with a 12 m range.
The 4 m LIDAR module is the lowest cost LIDAR and is based on the Neato XV LIDAR scanner. It works well at shorter distances down to 0.13 m and has a sampling rate of over 1700 points/second. For crawling to hallway-sized passages it is the better choice due to its denser sampling and accuracy at close-range. It has a low power consumption allowing for longer battery life. This was the LIDAR originally developed for the Caveatron and was used to collect most of the sample data. The 4 m LIDAR is a triangulation-based system design so requires the use of flat windows for its enclosure, resulting in a small occluded area at corner.
The 25 m LIDAR module is based on the Scanse SWEEP LIDAR. It is suited for hallway sized passages and larger and has good long range sensitivity out to 25 m. It is also a little smaller and lighter than the 4 m LIDAR module. However, it has a 1000 points/second sampling rate so provide a lower point cloud density and has measurement error that increases to large values at ranges less than 1 meter, so is not well suited to crawlways or other small passages. It also has a higher power consumption than the 4 m LIDAR, so has about 15-20% less run time. The 25 m LIDAR is a Time-of-Flight based system so can be designed inside a clear dome-style enclosure, providing a full 360º of unobscured scanning.
The LIDAR modules are connected only by two thumb screws and a twist-lock cable connector, so can be quickly and easily changed in the field. That way the LIDARs can be interchanged depending on the type of cave passage to scan. Separate calibrations are performed for each LIDAR module and the system automatically detects the type of LIDAR attached to load the correct calibration parameters. The Caveatron can also be used without any LIDAR module attached allowing it to act as an electronic survey instrument for collecting conventional survey shot data.