Photogrammetry is the future in inspection surveys providing high detail 3D mosaics of subsurface features or installations.
MMT has since 2015 been performing coarse photogrammetry for larger areas and detailed high resolution photogrammetry for several different applications such as site surveys, wreck inspections, pipeline inspections and structure inspections.
Multiple overlapping photos (typical overlap is 80%) are taken with two ROV parallel-mounted Cathx cameras. The images are positioned using time-tagging with microsecond precision stored in a database. This enables the use of post-processed high precision tracks to be used and even better final accuracy of the positioning.
By using markers digitised from several sources, the photos can be aligned perfectly and modelled into 3D.
MMTs photogrammetry processing work flow is semi-automated with ongoing development towards full automation, lowering costs for personnel and increasing utilization of the processing PC cluster without waiting time for human intervention.