OPR-G380-TJ-24 Approaches to Charleston, SC South Carolina H13983 11NM SSE of Charleston Entrance -0400 2024-07-25 2024-10-13 DOC/NOAA/NOS/OCS -- Office of Coast Survey hsd.chief@noaa.gov NOAA Ship Thomas Jefferson (S222) CC0-1.0 (NOAA Field Units) CC0-1.0 https://creativecommons.org/publicdomain/zero/1.0/ https://creativecommons.org/publicdomain/zero/1.0/legalcode These data were produced by NOAA and are in the public domain within the United States. NOAA waives any potential copyright and related rights in these data worldwide through the Creative Commons Zero 1.0 Universal Public Domain Dedication (CC0). H13983_MB_1m_MLLW_1of1 Projected UTM 17 North American Datum 1983 (2011) Mean Lower Low Water found by multi beam Yes Yes 2.0m (General 1) 10% (General 1) Yes Yes No 1m (Exceptional) N/A 0.25m (Critical) 0.75% (Exceptional/Critical) 369958000 S222 Positioning and Attitude System Applanix POS MV 320 v5 POS MV 6497 2024-06-05 Positioning and Attitude System Applanix POS MV 320 v5 POS MV 8959 1970-01-01 Multibeam Kongsberg Maritime EM 2040 EM 2040 40122 kHz 2024-03-27 2024-04-04 Conductivity, Temperature, and Depth Sensor AML Oceanographic MVP200 M12981 n/a n/a 1970-01-01 Conductivity, Temperature, and Depth Sensor AML Oceanographic MVP-X MVP-X CTD 9006 n/a 2024-02-08 2024-04-01 Sound Speed System Teledyne RESON SVP 70 SVP 70 1013077 n/a 2024-01-09 Sound Speed System Teledyne RESON SVP 70 SVP 70 0614179 n/a 2023-10-23 The NOAAS Thomas Jefferson (Vessel S222), on a sheet encompassing 1002.1 linear nautical miles of survey, collected a combined total of approximately 53.1 linear nautical miles of MBES crosslines, constituting roughly 5.3% of mainscheme mileage. A 1 meter Combined Uncertainty and Bathymetric Estimator (CUBE) surface was created for both the mainscheme and crossline data and compared using the Pydro 24 tool, "Compare Grids." The results of this comparison indicate that 100% of compared gridnodes are within the fraction of allowable error for depth/height, exceeding the minimum specification of 95% set in NOAA's 2024 Hydrographic Surveys Specification and Deliverables (HSSD). The resulting mean and standard deviation of uncertainty between the two surfaces was -0.01m and 0.03m, respectively. Summary plot of uncertainty between mainscheme and crossline surfaces of H13983 file:///Q:/OPR-G380-TJ-24/Surveys/H13983/01_HDR/Reports/AHB_Made/H13983_MB_1m_MLLW_Final-H13983_XL_1m_MLLW_depth_delta_2024.png A Node Depth vs. Allowable Error Fraction plot of mainscheme and crossline surfaces for H13983 file:///Q:/OPR-G380-TJ-24/Surveys/H13983/01_HDR/Reports/AHB_Made/H13983_MB_1m_MLLW_Final-H13983_XL_1m_MLLW_fracAllowErr_vsDepth_Overview.png A statistical analysis of grid layers was conducted to assess the quality of bathymetry. The Pydro 24 tool, "Grid QC," was used to assess grid density, resolution, and uncertainty against the allowable standards specified in the 2024 HSSD. This survey was assigned the quality metrics of General 1 - a metric which over 99.5%+ of delivered grids surpassed. a histogram of node data density file:///Q:/OPR-G380-TJ-24/Surveys/H13983/01_HDR/Reports/AHB_Made/H13983_MB_1m_MLLW_Final_1of1.QAv7.density.png a histogram of node uncertainty as a fraction of allowable TVU file:///Q:/OPR-G380-TJ-24/Surveys/H13983/01_HDR/Reports/AHB_Made/H13983_MB_1m_MLLW_Final_1of1.QAv7.tvu_qc.gn1.png AHB HDR Review found H13983 attained quality metric Critical during Grid QC, where 99.9% soundings pass. Grid QC derived histogram of node uncertainty as a fraction of allowable TVU attaining quality metric "Critical." file:///Q:/OPR-G380-TJ-24/Surveys/H13983/01_HDR/Images/HDR_Images/H13983_MB_1m_MLLW_1of1.QAv7.tvu_qc.cri.png After initial collection, MBES data underwent a thorough process of editing and inspection using a series of visual inspections and NOAA's Pydro 24 QC tool, "Flier Finder," to clean gridded surfaces of erroneous fliers that inaccurately affected seabed measurements - and to ensure that no systematic errors were present. Teledyne's CARIS software was used to generate and examine a 1m CUBE surface as well as its uncertainty and standard deviation layers in order to further visually inspect for fliers. Survey coverage was assessed daily by the field unit as part of night processing to identify data gaps to be addressed. Gaps in coverage that are larger than HSSD specifications are known as holidays. Various methods were utilized to aid in holiday identification including visual inspection and NOAA's Pydro 24 QC tool, "Holiday Finder." "Holiday Finder," when given a 100% bathymetric CUBE surface, finds gaps in data larger than HSSD specifications and returns a number of files used in Caris HIPS & SIPS that aids in holiday identification and acquisition planning. Holidays were iteratively collected throughout the survey operation - ultimately ensuring no distinguishable holidays exist by the submittal of this survey. The data of this entire survey was acquired in accordance with the requirements set forth in the 2024 HSSD and all data falls within applicable IHO and HSSD standards (encompassing data gaps, density, and uncertainty). Thus, the data in this entire survey is adequate to supersede previous data. Imagery coverage assessment was not performed for this survey Data interpolation was not performed for this survey Sheet H13983 junctions with the 2015 sheet H12805. Junction comparisons were run on both distinct sections of H12805 that overlap with H13983 using the Pydro 24 tool, "Compare Grids," and the results are shown below: A junction comparison was conducted between sheets H13983 and H12805 (the 50cm SR bag_2of4 as found on NCEI's data bathymetric viewer). The results of this comparison indicate that 100% of the compared grid nodes exceed General 1 standards for allowable error fraction. The resulting mean of this comparison was a mean of -0.05m and a standard deviation of 0.16m - verifying the consistency of the data. Summary plot of uncertainty between mainscheme of H13983 and H12805 file:///Q:/OPR-G380-TJ-24/Surveys/H13983/01_HDR/Reports/AHB_Made/H13983_MB_1m_MLLW_Final-H12805_MB_50cm_MLLW_2of4_depth_delta_2024.png A Node Depth vs. Allowable Error Fraction plot for mainscheme junction of H13983 and H12805 file:///Q:/OPR-G380-TJ-24/Surveys/H13983/01_HDR/Reports/AHB_Made/H13983_MB_1m_MLLW_Final-H12805_MB_50cm_MLLW_2of4_fracAllowErr_vsDepth_Overview.png A junction comparison was conducted between sheets H13983 and H12805 (the 1m SR bag_3of4 as found on NCEI's data bathymetric viewer). The results of this comparison indicate that 100% of the compared grid nodes exceed General 1 standards for allowable error fraction. The resulting mean of this comparison was a mean of 0.05m and a standard deviation of 0.16m - verifying the consistency of the data. Summary plot of uncertainty between mainscheme of H13983 and H12805 file:///Q:/OPR-G380-TJ-24/Surveys/H13983/01_HDR/Reports/AHB_Made/H13983_MB_1m_MLLW_Final-H12805_MB_1m_MLLW_3of4_depth_delta_2024.png A Node Depth vs. Allowable Error Fraction plot for mainscheme junction of H13983 and H12805 file:///Q:/OPR-G380-TJ-24/Surveys/H13983/01_HDR/Reports/AHB_Made/H13983_MB_1m_MLLW_Final-H12805_MB_1m_MLLW_3of4_fracAllowErr_vsDepth_Overview.png N/A The system echo sounders have the dynamic range to accommodate the relatively homogeneous survey area. The frequency was held constant at 300 kHz while the system automatically controlled pulse type. No special techniques were used outside of normal considerations for quality data acquisition for a bathymetric survey. Sound speed profiles were collected at the start of acquisition each day and at a minimum of once every four hours in order to apply appropriate absorption coefficients during acquisition. Please refer to section 4.3.2.1.2 Acoustic Backscatter Imagery of the Field Procedures Manual (FPM 2020) for the backscatter post-processing workflow. Information about uncertainty values used for data processing can be found within the Caris HIPS & SIPS processing project and in the associated Hydrographic Vessel Files (HVFs) for each platform. Uncertainty results for H13983 can be found in the Statistical Analysis section of the Quality Control Procedutes in this document. Holiday lines collected on DN287 (10/13/24) display evidence of applied sound speed data which does not fully represent the real-time sound speed through the water column - as evidenced by an upside down parabolic shape at the edges of the swath. Due to operational time constraints and no available applicable sound speed profiles, this data was unable to be corrected. However, DN287 lines and previously collected data display an approximate difference in depth of 0.1m with a further 0.1m standard deviation. Overall, no significant change in the surface is created from this error source - and, as outlined in the Quality Control Procedures tab, this survey still surpasses all data quality metrics. Unusual IMU dropouts and vertical offset issues were encountered on this survey. In an effort to troubleshoot, the POS computer system (PCS POS MC320 v5) was replaced (DN261 – 09/17/24) and a subsequent patch test was conducted to update the HIPS Vessel File (hvf). As S222 continued to encounter issues, the POS Inertial Measurement Unit (IMU) was replaced (DN272 - 09/28/24) alongside a new patch test and updated hvf. Any affected lines were either updated or reacquired and processed with the newest hvf - and no significant offsets persist. Coast Pilot Report 2024-11-06 Trained Marine Mammal Observers list 2024-03-05 NCEI Sound Speed Data 2024-11-04 Final Survey Outline 2024-10-18 Potentially Sensitive Data Findings 2024-10-08 As Chief of Party, field operations for this hydrographic survey were conducted under my direct supervision, with frequent personal checks of progress and adequacy. I have reviewed and approved all data and metadata. The survey meets or exceeds requirements as set forth in the Project Instructions and NOS Hydrographic Surveys Specifications and Deliverables. The survey is complete and no additional work is required with the exception of any deficiencies noted in the Report of Survey. CDR Megan R. Guberski Chief of Party Alessandra M DiTommaso Survey Technician Kylea Perrin Survey Technician