Matlab codes for measuring bubble sizes and heights above the seafloor from underwater video footage by manually picking bubble axes.
The footage must contain the exit point of the bubbles on the seafloor and a known reference distance on the seafloor (usually in the form of two lasers for most underwater cameras).
The geometry of the calculations uses Canadian Grids (Wakefield and Genin, 1987, doi:10.1016/0198-0149(87)90148-8) combined with additional geometry (McGovern, 2012 (thesis)).
Uncertainties in the bubble sizes and rise heights come from the amount of bubble deviation towards or away from the camera as it rises. Since this deviation can't be measured, the code contains hard-coded deviation distances that increase with rise height. These deviations were originally measured from a selection of seeps along the Hikurangi Margin New Zealand (Higgs, 2019).
Higgs, Ben; Mountjoy, Joshu J; Crutchley, Gareth J; Townend, John; Ladroit, Yoann; Greinert, Jens; McGovern, Colin (2019): Seep-bubble characteristics and gas flow rates from a shallow-water, high-density seep field on the shelf-to-slope transition of the Hikurangi subduction margin. Marine Geology, 417, 105985, https://doi.org/10.1016/j.margeo.2019.105985
Median Latitude: -38.583500 * Median Longitude: 178.667000 * South-bound Latitude: -38.917000 * West-bound Longitude: 178.417000 * North-bound Latitude: -38.250000 * East-bound Longitude: 178.917000