Multi-beam backscatter measurements used to infer seabed habits
Backscatter from multi-beam sonar (MBS) was used to discriminate ecologically relevant seabed characteristics based on 62 reference sites sampled with georeferenced video, sediment grab and rock dredge between 50 and 500 m water depth. A simple biotope characteristic of soft (unconsolidated) and har...
| Main Authors: | , , |
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| Format: | Journal Article |
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Elsevier Ltd
2010
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| Online Access: | http://hdl.handle.net/20.500.11937/38519 |
| Summary: | Backscatter from multi-beam sonar (MBS) was used to discriminate ecologically relevant seabed characteristics based on 62 reference sites sampled with georeferenced video, sediment grab and rock dredge between 50 and 500 m water depth. A simple biotope characteristic of soft (unconsolidated) and hard (consolidated) was used to compare the acoustic backscatter data with the data on mega-epifauna and substrate type obtained from video and physical sampling. Substrate type of homogeneous reference sites was predicted by matching the backscatter incidence angle profile (0–70°) to that of a seabed scattering model. Referencing the seabed backscatter to a consistent incidence angle (40°) gave a metric with high spatial resolution (2.4–20 m), which minimised errors of range, incident angle and beam compensation. This simple metric provided a consistent approach to analyse and interpret the data and was strongly correlated with substrate type and faunal functional groups. The high resolution backscatter metric was a closer match to the small spatial scale of seabed patch lengths observed by video (50% <50 m). |
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