S-J901-NRTST-22 Biloxi Bay Biloxi, MS NOAA NRT-Stennis H13651 1 Biloxi Bay Mississippi United States 20000 2022 LTJG Robert Sobelsohn Basic Hydrographic Survey 2022-05-25 2022-07-14 2023-03-23 Multibeam Echo Sounder Side Scan Sonar Multibeam Echo Sounder Backscatter meters UTC Pacific Hydrographic Branch 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). NOAA The survey area is located in Biloxi, Mississippi, within the sub locality of Biloxi Bay. 30.42436111111111 88.91586111111111 30.284931 88.762704 H13651 sheet limits (in gray) overlaid onto ENC US4MS12M. SupportFiles\Area Surveyed.JPG Data were acquired to the survey limits in accordance with the requirements in the Project Instructions and the March 2022 NOS Hydrographic Surveys Specifications and Deliverables (HSSD) as shown in the figure below. In all areas where the 2 meter depth contour or the sheet limits were not met, the Navigable Area Limit Line (NALL) was defined as the inshore limit of bathymetry due to the risks of maneuvering the survey vessel in close proximity to rocky shorelines or shoreline constructions. Survey data from this project is intended to supersede all prior survey data in the common area. The entire survey is adequate to supersede previous data. Data acquired in H13651 meets multibeam echo sounder (MBES) coverage requirements for complete coverage, as required by the HSSD. This includes crosslines (see Section B.2.1), NOAA allowable uncertainty (see Section B.2.10), and density requirements (see Section B.2.11). All waters in survey area. Object Detection Coverage (Refer to HSSD Section 5.2.2.2) Survey coverage was in accordance with the requirements listed above and in the HSSD. H13651 MBES coverage overlaid on SSS coverage extents. SupportFiles\H13651_Survey.png S3005 0.0 0.0 0.0 0.0 0.0 213.53 0.0 6.06 0.0 S3008 0.0 0.0 0.0 0.0 0.0 256.08 0.0 19.64 0.0 EB240 0.0 0.0 0.0 0.0 0.0 17.01 0.0 4.22 0.0 0.0 0.0 0.0 0.0 0.0 486.62 0.0 29.92 0.0 17.26 0 0 0 0 8.54 2022-07-14 2022-07-18 2022-07-24 2022-07-25 2022-07-26 2022-08-01 2022-08-02 2022-08-03 2022-08-14 2022-08-18 2022-08-21 2022-08-22 2022-08-23 2022-08-24 2022-08-25 2022-08-28 2022-08-29 2022-08-30 2022-08-31 2022-09-01 2022-09-05 2022-09-06 2022-09-08 2022-09-14 2022-09-18 2022-09-19 2022-09-20 2022-09-21 2022-09-22 2022-10-18 2022-10-19 2022-10-20 2022-10-26 2022-10-30 2022-10-31 2022-11-07 2022-11-08 2022-11-09 2022-11-10 2022-12-07 2022-12-27 2022-12-28 2023-03-21 2023-03-22 2023-03-23 Refer to the Data Acquisition and Processing Report (DAPR) for a complete description of data acquisition and processing systems, survey vessels, quality control procedures and data processing methods. Additional information to supplement sounding and survey data, and any deviations from the DAPR are discussed in the following sections. S3005 31.0 1.2 S3008 31.0 1.2 EB240 7.9 0.21 MBES Kongsberg Maritime EM 2040C MBES Teledyne RESON SeaBat T20-P SSS EdgeTech 4125 SSS Tritech Starfish 453 Conductivity, Temperature, and Depth Sensor SonTek CastAway-CTD Sound Speed System AML Oceanographic MicroX SV Positioning and Attitude System Applanix POS MV SurfMaster Positioning and Attitude System Applanix POS MV 320 v5 Sound Speed System Valeport SWiFT SVP Vessel configurations, equipment operations, data acquisition, and processing were consistent with specifications described in the DAPR. 29.92 LNM of crosslines were collected for H13651 resulting in a crossline percentage of 17.26%, which does meet the minimum percentage and distribution requirements as specified in the HSSD, Section 5.2.4.2. Uncertainty standards between a 50cm Mainscheme grid versus a 50cm Crossline grid showed 99.5+ % of nodes passed, which passes NOAA IHO TVU requirements. H13651 MBES crossline data, shown in pink, overlaid on mainscheme SSS data, shown in black. SupportFiles\H13651_Crossline_Locations.png H13651 MBES crossline/mainscheme comparison. SupportFiles\H13651_MB_50cm_MS-H13651_MB_50cm_XL_depth_delta.png H13651 MBES Crossline vs. Mainscheme Distribution, 99.5+% of nodes pass. SupportFiles\H13651_MB_50cm_MS-H13651_MB_50cm_XL_fracAllowErr_Freq.png H13651 Nodes vs. Allowable Error Fraction SupportFiles\H13651_MB_50cm_MS-H13651_MB_50cm_XL_fracAllowErr_vsDepth.png ERS via VDATUM 0.0 0.17 S3005 2 N/A 0 0.5 S3008 2 N/A 0 0.5 EB240 2 0 0 0.5 The bathymetric surface's uncertainty layer is compliant with HSSD 2022 uncertainty standards. Over 99.5+ % of all nodes pass uncertainty standards as shown in the figure below. Node Depth vs. Total Vertical Uncertainty (TVU) SupportFiles\H13651_MB_50cm_MLLW.GQv6.depth_vs_tvu_qc.full_range.png Node Depth vs. TVU, Zoom on good data (TVU QC < 1.0) SupportFiles\H13651_MB_50cm_MLLW.GQv6.depth_vs_tvu_qc.zoom_on_good_data.png NOAA HSSD Uncertainty Standards SupportFiles\H13651_MB_50cm_MLLW.GQv6.tvu_qc.png Concur with clarification that Georeference Bathymetry the "Measure Sound Velocity" in the HDCS data is at 4 m/s and the "Surface Sound Velocity" is at 0.2 m/s. H13651 Sound speed uncertainties file:///M:/SJ901NRTST22/Surveys/H13651/01_HDR/Working/H13651%20sound_speed.png No Junctions were prescribed per Project Instructions. There are no contemporary surveys that junction with this survey. Sonar system quality control checks were conducted as detailed in the quality control section of the DAPR. None Exist There were no conditions or deficiencies that affected equipment operational effectiveness. None Exist There were no other factors that affected corrections to soundings. Casts were conducted at the start of acquisition each day and at a minimum of one every four hours during launch acquisition. Cast frequency met or exceeded 1 cast per every 4 hours of survey. H13651 SVP cast locations overlaid on mainscheme SSS coverage. SupportFiles\H13651_SVP_Locations.png All equipment and survey methods were used as detailed in the DAPR. Density The surface was analyzed using HydrOffice QC Tools Grid QA feature. Density requirements for H13651 were achieved with at least 99% of surface nodes containing five or more soundings as required by HSSD Section 5.2.2.3. The few nodes that did not meet density requirements are due to sparse data in the outer beams. H13651 Data Density SupportFiles\H13651_MB_50cm_MLLW.GQv6.density.png H13651 Node Depth vs. Sounding Density SupportFiles\H13651_MB_50cm_MLLW.GQv6.depth_vs_density.png All data reduction procedures conform to those detailed in the DAPR. All sounding systems were calibrated as detailed in the DAPR. All equipment and survey methods were used as detailed in the DAPR. H13651 300 kHz MBAB coverage at 2m resolution. SupportFiles\H13651_MBAB_300kHz_Coverage.png H13651 400 kHz MBAB coverage, overlaid on mainscheme SSS coverage, at 2m resolution. SupportFiles\H13651_MBAB_400kHz.png CARIS HIPS and SIPS 11.4 Applanix POSPac 8.9 QPS Fledermaus 7.10.2 NOAA Profile Version 2022 H13651_MBES_50cm_MLLW CARIS Raster Surface (CUBE) 0.5 0.5 8.6 NOAA_0.5m MBES Trackline H13651_MBES_50cm_MLLW_Final CARIS Raster Surface (CUBE) 0.5 0.5 8.6 NOAA_0.5m MBES Trackline H13651_SSSAB_1m_450kHz_1of2 SSS Mosaic 1 N/A 100% SSS H13651_SSSAB_1m_450kHz_2of2 SSS Mosaic 1 N/A 200% SSS H13651_MBAB_2m_300kHz MB Backscatter Mosaic 2 N/A MBES Trackline H13651_MBAB_2m_400kHz MB Backscatter Mosaic 2 N/A MBES Trackline The NOAA CUBE parameters defined in the HSSD were used for the creation of all CUBE surfaces for H13651. The surfaces have been reviewed where noisy data, or "fliers", are incorporated into the gridded solutions causing the surface to be shoaler or deeper than the true sea floor. Where these spurious soundings cause the gridded surface to be shoaler or deeper than the reliably measured seabed by greater than the maximum allowable Total Vertical Uncertainty at that depth, the noisy data have been rejected by the hydrographer and the surface recomputed. Flier Finder, part of the QC Tools package within HydrOffice, was used to assist the search for spurious soundings following gross cleaning. Flier Finder was run iteratively until all remaining flagged fliers were deemed to be valid aspects of the steep slopes and dynamic nature of the seafloor. Data Processing Issues with Chucky During the processing of H13651 many issues were encountered that have since made working with the data more difficult. Specific issues were encountered with Pydro 22's batch processor Chucky leading to multiple iterations of the processed data corrupting. As a result of these corruptions there was some data loss and additional issues with the data while reprocessing. This has lead to gaps in the survey areas as well as multiple lines refusing to process. Many attempts have been made to remedy this situation both by the remaining field team and by HSTB with mixed results. All issues that have not/were not able to be fixed are shown in the images below. Large SSS Data Gap, Project Outline in Red SupportFiles\SSS_Big_Data_Gap.PNG Medium SSS Data Gap, Project Outline in Red SupportFiles\SSS_Data_Gap.PNG Small SSS Data Gap, Project Outline in Red SupportFiles\SSS_Data_Gap_2.PNG Missing MBES Data from EB240 SupportFiles\Missing_EB_MBES_Data.PNG Missing MBES Data from S3005 SupportFiles\Missing_MB_Trackline.PNG Additional information discussing the vertical or horizontal control for this survey can be found in the accompanying HVCR. Mean Lower Low Water ERS via VDATUM OPR-J901-NRTST-22_VDatum_100m_NAD83-MLLW_geoid12b.csar All soundings submitted for H13651 are reduced to MLLW using VDatum techniques as outlined in the DAPR. Field installed tide and GPS stations were not utilized for this survey. There is no HVCR report included with the submission of H13651. North American Datum 1983 Projected UTM 16 RTX The horizontal datum for this project is North American Datum of 1983 (NAD 83). The projection used for this project is Universal Transverse Mercator (UTM) Zone 16. Horizontal and vertical positioning were achieved in accordance with practices outlined in the DAPR. Processing and products for Survey H13651 were conducted and completed in NAD 83 per HSSD specification. Refer to the DAPR for a complete description of horizontal control procedures. RTX Precise Positioning-Real Time Extended (PP-RTX) processing methods were used in Applanix POSPac MMS software to produce Smoothed Best Estimate of Trajectory (SBET) files and their associated uncertainty for post-processing horizontal correction. Trimble CenterPoint RTX is the preferred method for the positioning for the Gulf of Mexico where horizontal accuracies of 2cm or less may be achieved without the use of reference stations. CenterPoint RTX service was accessed via an internet connection within one hour after field operations had concluded. Applanix POSPac MMS 8.8 software was used to access Trimble RTX servers to produce a Smoothed Best Estimate of Trajectory (SBET) file implementing the Applanix proprietary "SmartBase" algorithm. The SBET file consisted of GPS position and attitude data corrected and integrated with inertial measurements and correctors which were then exported to the reference ellipsoid. These SBET navigation and attitude files were applied to all lines in CARIS and supersede initial positioning and attitude data. The Wide Area Augmentation System (WAAS) was used for real-time horizontal control during data acquisition. A chart comparison was conducted between survey H13651 soundings and previously charted ENC soundings using procedures outlined in the DAPR. H13651 vs. US5MS11M Chart Sounding Comparison SupportFiles\Chart_Comparison_US5MS11M.png H13651 vs. US5MS21M Chart Sounding Comparison SupportFiles\Chart_Comparison_US5MS21M.png US5MS11M 40000 62 2022-02-08 2022-04-08 US5MS21M 40000 48 2022-01-05 2022-04-11 Refer to the H13651 Final Feature File. Refer to the H13651 Final Feature File. Survey H13651 has 7 new features that are addressed in the H13651 Final Feature File. Of these features, there are 7 new Obstructions, 0 new Seabed Areas, 0 new Underwater Rocks of which 0 are submitted as DTONs. There were no discrepancies found between the ENC charted contours and the surveyed contours of the channel for survey H13651. There were no differences found between the survey depths and the recorded controlling depths, tabulated depths, and reported depths of all maintained channels within survey H13651. Refer to the H13651 Final Feature File. No Maritime Boundary Points were assigned for this survey. No bottom samples were required for this survey. Refer to the H13651 Final Feature File. During processing of H13651, three features were found in side scan coverage that were not covered with multibeam during preliminary investigations. Therefore, the least depths for these two features have been reported as unknown in the final feature file. An additional contact was found to only have partial multibeam coverage over it. The shoalest known point was used for the "Value of Sounding" but this should be refined with more accurate data. The hydrographic field party has intentions of investigating these features in the future to update the least measurements. Please refer to the H13651 Final Feature File for more information. No platforms exist for this survey. No ferry routes or terminals exist for this survey. No abnormal seafloor or environmental conditions exist for this survey. No present or planned construction or dredging exist within the survey limits. No new surveys or further investigations are recommended for this area. No new ENC scales are recommended for this area. As Chief of Party, field operations for this hydrographic survey were conducted prior to my arrival with the team. I have reviewed the attached survey data and reports. All field sheets, this Descriptive Report, and all accompanying records and data are approved. All records are forwarded for final review and processing to the Processing Branch. The survey data meets or exceeds requirements as set forth in the NOS Hydrographic Surveys Specifications and Deliverables, Field Procedures Manual, Letter Instructions, and all HSD Technical Directives. These data are adequate to supersede charted data in their common areas. This survey is complete and no additional work is required with the exception of deficiencies noted in the Descriptive Report. Robert Sobelsohn Chief of Party 2025-03-05