NCCOS mapping: seafloor mapping products for the Florida Keys National Marine Sanctuary from 2004-01-01 to 2019-09-22 (NCEI Accession 0170215)

In this accession, NCEI has archived multiple versions of these data. The latest (and best) version of these data has the largest version number.

Methods:
Multibeam sonar data (seabed elevation) and acoustic imagery data (backscatter) were collected using multibeam echosounders (MBES) on the NOAA Ship Nancy Foster (NF) and NOAA Ship Thomas Jefferson (TJ) from cruises during the years 2004-2019. The multibeam datasets cover areas within the FKNMS and some adjacent areas in the Atlantic Ocean. The data sets between 2004 and 2017 were preliminarily processed by NCCOS and corrected for motion, sound speed, and other major artifacts. These data were further processed and reviewed by Geodynamics, who conducted an initial processing to arrange the data into a modern working CARIS project, then conducted a full processing of the data and incorporated a NOAA zoned definition file (ZDF) to increase vertical accuracy and permit NCCOS’s later use of the data for habitat characterization.
The original bathymetry data from the NF was cleaned to IHO S-44 specs. Data from the two TJ cruises, survey areas H10957 and H11340, were accompanied with working BAG files and did not require full processing. MBES datasets collected in 2018 and 2019 were cleaned and processed by NOAA Ship Nancy Foster personnel only.

The acoustic imagery (backscatter) data that exists for 3 areas only (2004-2018 Tortugas Ecological Reserve North and South, 2010-2017 Upper Keys, 2012-2018 Marquesas) were reviewed and processed by NCCOS using Fledermaus geocoder. The resulting datasets were mosaicked together to produce a geo-referenced tiff of the main areas of interest (excluding ship transit data).
Eight complexity surfaces (bathymetry mean, bathymetry standard deviation, curvature, curvature plan, curvature profile, rugosity, slope, and slope of slope) were used to generate the Principle Component Analysis (PCA) data layers for all MBES datasets. The Geotiff is the result of a PCA using these 8 derived complexity surfaces from the MBES and LiDAR datasets. The PCA creates a file consisting of 3 bands, or principal components, that account for the maximal amount of variance in the original 8 derived complexity surfaces. The PCA is the primary layer used in the benthic habitat classification process. The classification was checked against all of the underwater videos and stills collected within the classification area to ensure the final product corresponded as closely as possible to the benthos identified in those ground verification points. NCCOS reviewed the PCA’s for logical consistency in ArcGIS.

NCCOS and its collaborators collected images and video clips during research cruises in the FKNMS during 2012-2019, which were edited to focus on benthic habitat, and analyzed for groundtruth validation of benthic habitat type. The underwater video device is referred to as a drop camera consisting of two video cameras mounted in a stainless steel frame. One is a lower resolution camera tethered to the surface with cable to allow viewing by NCCOS personnel at the surface. This allowed surface personnel to visualize the bottom and ensure the frame did not impact the bottom. The other video camera is a GoPro, used to collect HD video. The archived video were collected on a November 2018 NOAA Ship Nancy Foster cruise and an August 2019 mission on a FKNMS 30 foot outboard vessel. The video was viewed by NCCOS personnel for groundtruth validation of habitat type at pre-chosen points. These data were used for training data in benthic habitat classification using MBES data in the Dry Tortugas Ecological Reserve and a large area to the north and west of the Marquesas. No QA/QC of the video was performed.



Submission Package ID: TC3L6F and GG4LRA