Structure from Motion Photogrammetry

In 2022, Structure from Motion (SfM) photogrammetry was implemented at 35 Amaala and 113 TRS sites. All of those are in shallow (5m-20m deep) coral reef habitat. Each SfM site is a permanently marked 20m-by-5m plot. As the same sections of reef are re-surveyed each time, we conduct an SfM, and the resulting data sets allow us to make precise and accurate estimates of change.

SfM photogrammetry allows our team to generate highly detailed digital models of the sites. These include scaled 2D photomosaics and digital elevation models (DEMs).

We use a machine learning tool (CoralNet) to automatically extract cover data from the photomosaics and extract measures of reef structural complexity from the DEMs. As the AI analysis tools improve over the next few years, we aim to use more automated SfM approaches to track the fate (growth, mortality, recruitment) of individual corals within these plots.