In situ sediment profile images from south San Francisco Bay, California, 2023-2025

In situ images of the sediment-water interface and sediment profiles were collected to characterize the top layer of the sediment bed (less than 15 cm sediment depth) prior to dredged material placement and post dredge material placement in south San Francisco Bay, California. Several sites within the placement area, as well as sites outside of the placement area, and near time-series stations were collected. The photos were acquired during four separate trips: August 2023 (pre-placement), October 2023 (pre-placement), January 2023 (post-placement), and February (greater than 1 year post-placement). The sediment profile imaging system consisted of a Blackfly S Board-level BFS-GE-50S5C0BD2 camera that incorporates a Sony IMX264 sensor and has an m12-mount type wide-angle 4.4 mm lens. The resulting field of view was approximately 7x15 cm at the window, with a resolution of 0.0667 mm per pixel when the vertically (portrait) oriented window of the housing was pushed into the sediment bed. The camera was secured horizontally in Sediment Profile Imaging (SPI) camera waterproof housing from OceanInstruments, which was lowered to the bay floor at the different stations and pushed from above into the sediment bed using a rigidly attached pole. The images captured using the system show a profile view which includes a surface view of the sediment bed where the window was above the water-sediment interface, and/or a high-resolution sediment profile where the window extended vertically down into the sediment bed and was flush with the sediment. The maximum depth below the water-sediment interface recorded by the sediment profile imaging camera was approximately 15 cm.

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  "010:12"
]

[
  "geospatial"
]