OPR-J348-KR-17Mississippi Sound and VicinityBiloxi, MSDavid Evans and Associates, Inc.H1306685 NM Southwest of Dauphin IslandAlabamaUnited States200002017Jonathan L. Dasler, PE, PLS, CHNavigable Area2017-11-032017-10-232017-10-26Multibeam Echo SounderSide Scan SonarMultibeam Echo Sounder BackscattermetersUniversal Transverse Mercator (UTM)UTCAtlantic Hydrographic BranchContractorDavid Evans and Associates, Inc. (DEA) conducted a hydrographic survey of the assigned area in the Mississippi Sound and vicinity. Survey H13066 was conducted in accordance with the Statement of Work (July 21, 2017) and Hydrographic Survey Project Instructions (November 3, 2017).
The Hydrographic Survey Project Instructions reference the National Ocean Service (NOS) Hydrographic Surveys Specifications and Deliverables Manual (HSSD), 2017 as the technical requirements for this project.30.207404111188.343099694430.131609194488.2279403889Survey Limits were surveyed in accordance with the requirements in the Project Instructions and the HSSD.OPR-J348-KR-17 Assigned Survey Areasfile:///P:/NOAA00000028/0600INFO/0670Reports/H13066/Descriptive_Report/SupportFiles/OPR-J348-KR-17_Assigned_Survey_Areas.pngThe purpose of this project is to provide contemporary surveys to update National Ocean Service nautical charts and products. This hydrographic survey will support the dense vessel traffic transiting the Intracoastal Waterway extending from Biloxi to Pascagoula, Mississippi as well as the local fishing vessels and recreational boaters transiting further inshore. This area has been inundated by eight major tropical storms and hurricanes since it was last surveyed, including Hurricane Katrina. This survey will update the regional bathymetry and address over 50 chart discrepancies. In addition, this survey data will support the State of Mississippi and United States Army Corps of Engineers Mobile District as they plan a large barrier island restoration project in the vicinity of Ship Island. 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.All waters in survey area Acquire backscatter data during all multibeam data acquisition (HSSD Section 6.2)Sheets 7 -10: Water depths greater than 4 m Complete Coverage
(Refer to HSSD Section 5.2.2.3 Option B). Note: Survey Scale for Sheet 7 inset is 1:10,000. Survey H13066 was designated as Sheet 8 in the project instructions.
Complete coverage was obtained over the survey area using 100% side scan sonar coverage with concurrent multibeam echosounder (MBES) and backscatter. This coverage type follows Option B of the Complete Coverage requirement specified in Section 5.2.2.3 of the 2017 HSSD. Significant side scan sonar contacts were developed with multibeam sonar at complete coverage resolution as required by the coverage classification. Complete coverage multibeam was obtained within the search radii (160 meters for features labeled with "PA" or "rep", 240 meters for features labeled with "PD" or "ED", and 80 meters for all features without a position qualifier) for all feature disapprovals. Survey coverage was obtained within the survey area depicted in the Project Reference File (PRF) OPR-J348-KR-17_PRF_FINAL.000.H13066 Survey Outlinefile:///P:/NOAA00000028/0600INFO/0670Reports/H13066/Descriptive_Report/SupportFiles/H13066_SurveyOutline.pngS/V Blake02.3800.950384.83018.94002.3800.950384.83018.9404.89000021.072017-10-232017-10-242017-10-252017-10-26The OPR-J348-KR-17 Data Acquisition and Processing Report (DAPR), submitted with this survey, details equipment and vessel information as well as data acquisition and processing procedures. There were no vessel or equipment configurations used during data acquisition that deviated from those described in the DAPR.S/V Blake834.5S/V Blakefile:///P:/NOAA00000028/0600INFO/0670Reports/H13066/Descriptive_Report/SupportFiles/Blake.pngTeledyne RESONT50-PMBESEdgeTech4200-HFSSSApplanixPOS MV 320 v5Positioning and Attitude SystemRolls Royce / AML OceanographicMVP30-350 with AML Micro SV&PPrimary Sound Speed ProfilerAML OceanographicMicro SV XchangeSurface Sound SpeedSea-Bird ScientificSBE 19+ SeaCAT CTDSecondary Sound Speed ProfilerTrimbleSPS751RTK ReceiverCSI WirelessMBX-3SDGPS/Beacon ReceiverCrosslines were run across the entire survey area in order to provide a varied spatial and temporal distribution for analysis of internal consistency within the survey data.
Crossline analysis was performed using the CARIS Hydrographic Information Processing System (HIPS) Quality Control (QC) Report tool, which compares crossline data to a gridded surface and reports results by beam number. Crosslines were compared to a 1-meter CUBE surface encompassing mainscheme, fill, and investigation data for the entire survey area. The QC Report tabular output and plot are included in Separate II. The results of the analysis meet the requirements as stated in the 2017 HSSD.
Additional crossline analysis was performed by computing a 1-meter CUBE surface from the crossline data. The surface was then differenced from a 1-meter surface comprised of all mainscheme, fill, and investigation data. The resultant difference surface was exported using the Base Surface to ASCII function and statistics were compiled on the ASCII data.
Results from the crossline to mainscheme difference analysis are depicted in Figure 4. The primary contributors to the largest differences; 20 to 46 centimeters and -20 to -60 centimeters, are tidal zoning and sound speed artifacts and horizontal positioning over a long linear exposed pipeline, respectively.H13066 Crossline Differencefile:///P:/NOAA00000028/0600INFO/0670Reports/H13066/Descriptive_Report/SupportFiles/H13066_XL_MS.png00TCARIS/V Blaken/a1.00.5Additional discussion of these parameters is included in the DAPR.
During surface finalization in HIPS, the "Greater of the two values” option was selected, where the calculated uncertainty from Total Propagated Uncertainty (TPU) is compared to the standard deviation of the soundings influencing the node, and where the greater value is assigned as the final uncertainty of the node. The uncertainty of the finalized surfaces increased for nodes where the standard deviation of the node was greater than the TPU.
The resulting calculated uncertainty values of all nodes in the finalized 1-meter Complete Coverage multibeam surface range from 0.14 meters to 0.44 meters with a standard deviation of 0.01 meters.
To determine if surface grid nodes met International Hydrographic Organization (IHO) Order 1 specification, a ratio of the final node uncertainty to the allowable uncertainty at that depth was determined. As a percentage, this value represents the amount of error budget utilized by the uncertainty value at each node. Values greater than 100% indicate nodes exceeding the allowable IHO uncertainty.
For the 1-meter Complete Coverage multibeam surface, the allowable uncertainty utilized ranges from 25% to 84%. The mean allowable uncertainty for the surface is 28% with a standard deviation of 0.021.Survey H13066 junctions with prior surveys H11547, H11621, H11622 and with current surveys H13065 and H13067.
The Bathymetric Attributed Grids (BAGs) for surveys H11547, H11621, and H11622 were provided by NOAA for comparison with H13066.
The finalized H13066 surface was compared to each junction survey by generating a difference surface using CARIS HIPS.H11547200002006Terrasond, Ltd.SThe mean difference between H13066 and H11547 survey depths is three centimeters (H13066 deeper than H11547). The surveys agree well given the age of the prior survey and the difference in water level application. All differences observed in the junction analysis are within the IHO Order 1 allowable vertical uncertainty in the depth range of the survey.Junction results between H13066 1-meter and H11547 2-meter bathy gridsfile:///P:/NOAA00000028/0600INFO/0670Reports/H13066/Descriptive_Report/SupportFiles/H13066_1m_H11547_2m_Junction.pngH11621200002006Fugro Pelagos, Inc.NThe mean difference between H13066 and H11621 survey depths is twelve centimeters (H13066 deeper than H11621). The surveys agree well given the age of the prior survey and the difference in water level application. The majority of differences observed in the junction analysis are within the IHO Order 1 allowable vertical uncertainty in the depth range of the survey. In a few instances along the edges of migrating sediment waves, the maximum junction difference exceeds allowable vertical uncertainty.Junction results between H13066 1-meter and H11621 5-meter bathy gridsfile:///P:/NOAA00000028/0600INFO/0670Reports/H13066/Descriptive_Report/SupportFiles/H13066_1m_H11621_5m_Junction.pngH11622200002006Fugro Pelagos, Inc.NEThe mean difference between H13066 and H11622 survey depths is five centimeters (H13066 deeper than H11622). The surveys agree well given the age of the prior survey and the difference in water level application. All differences observed in the junction analysis are within the IHO Order 1 allowable vertical uncertainty in the depth range of the survey.Junction results between H13066 1-meter and H11622 5-meter bathy gridsfile:///P:/NOAA00000028/0600INFO/0670Reports/H13066/Descriptive_Report/SupportFiles/H13066_1m_H11622_5m_Junction.pngH13065200002017David Evans and Associates, Inc.WAt the time of writing, data from survey H13065 was still being processed. The Descriptive Report for H13065 will include the junction analysis with H13066.H13067200002017David Evans and Associates, Inc.EThe mean difference between H13066 and H13067 survey depths is two centimeters (H13066 shoaler than H13067). H13067 is also part of the OPR-J348-KR-17 survey project. The maximum differences are associated with sound speed, vessel motion artifacts and tidal offsets. The multimodal distribution of differences can most likely be contributed to miscalculations of the tidal zoning model discussed in greater detail in section B.2.6 of this report. All differences observed in the junction analysis are within the IHO Order 1 allowable vertical uncertainty in the depth range of the survey.Junction results between H13066 1-meter and H13067 1-meter bathy gridsfile:///P:/NOAA00000028/0600INFO/0670Reports/H13066/Descriptive_Report/SupportFiles/H13066_1m_H13067_1m_Junction.pngQuality control is discussed in detail in Section B of the DAPR. Results from weekly position checks and weekly multibeam bar checks are included in Separate I Acquisition and Processing Logs of this report. Sound speed checks can be found in Separate II Sound Speed Data Summary of this report.
Multibeam data were reviewed at multiple levels of data processing including: CARIS HIPS conversion, subset editing, and analysis of anomalies revealed in CUBE surfaces.None ExistThere were no conditions or deficiencies that affected equipment operational effectiveness.Tidal DifferencesThe largest differences observed during the crossline analysis appear to be related to limitations in the TCARI tidal model for the area. Mainscheme data acquired on October 23, 2017 (DN296) between 03:30 and 17:30 and October 24, 2017 (DN297) between 03:40 and 18:55 are approximately 10 to 25 centimeters shallower than overlapping crosslines collected on October 25, 2017 (DN298), shown in Figure 9. During acquisition, all three of the NWLON gauges used in the TCARI model for the project recorded higher than predicted tides. The gauges were experiencing a significant flood event caused by severe weather which passed through the region earlier in the week. The time of acquisition for the mainscheme lines in question (approximately 10 to 25 centimeters shallower) coincide with falling tides on DN 296 and DN297. It is the hydrographer's belief that the crossline differences result from TCARI inaccurately applying the flood event from Mississippi Sound through Petit Bois Pass to the offshore survey area. Crossline differences greater than 0.1 meters (shown in red) illustrating two distinct areas based on timefile:///P:/NOAA00000028/0600INFO/0670Reports/H13066/Descriptive_Report/SupportFiles/Tides_differences.pngPascagoula tide station (8741533) illustrating verified and predicted tides for DN’s 296 and 297, time periods of the greatest XL differences are encompassed with the black vertical linesfile:///P:/NOAA00000028/0600INFO/0670Reports/H13066/Descriptive_Report/SupportFiles/Tides_Verified.pngApproximately 15-minute intervalsA Rolls Royce Moving Vessel Profiler (MVP) was the primary instrument used to acquire sound speed readings during multibeam operations. MVP sound speed readings were measured at approximately 15-minute intervals during survey operations. Additional discussion of sound speed methods can be found in the DAPR.Survey speeds were maintained to meet or exceed along-track sounding density and side scan sonar ensonification requirements.
Side scan mosaics were thoroughly reviewed for holidays and areas of poor quality coverage due to biomass, vessel wakes, or other factors. A fill plan was created in order to acquire side scan data where holidays and significant poor quality coverage existed. Side scan sonar contacts were developed with multibeam sonar to obtain a least depth of the contact using Complete Coverage requirements.DensityThe sounding density requirement of 95% of all nodes, populated with at least five soundings per node, was initially not met due to equal angle outer beam spacing. A 60-degree swath filter was applied to certain lines specified below in order to increase the survey-wide sounding density. These survey lines, which were acquired in a deeper sections of the survey area, were reduced from the full 70-degree multibeam swath to 60-degrees with a HIPS swath filter.
The 60-degree swath filter was applied to the following lines:
DN297: 2017BL2971145 - 2017BL2972300
DN298: 2017BL2980024 - 2017BL2981222
DN299: 2017BL2990626
2017BL2990632
2017BL2990946
2017BL2990952
After the 60-degree swath angle filter was applied, the sounding density requirement was verified by exporting the density child layer of the finalized CUBE surface to an ASCII text file and compiling statistics on the density values. More than 97% of all final CUBE surface nodes contained five or more soundings.Data gaps in bathymetric coverageThe final submitted CUBE surface contains a number of data gaps caused by shadows from suspended biologic phenomena, such as schools of fish or dolphins. These gaps do not meet the definition of a holiday for Complete Coverage Surveys (Option B) as defined in section 5.2.2.3 of the HSSD. In all cases, the side scan sonar mosaic was verified to not also contain a gap in coverage.Data reduction procedures for survey H13066 are detailed in the DAPR. A summary multibeam processing log is included in Separate I of this report.All sounding systems were calibrated as detailed in the DAPR.Multibeam backscatter was logged in Hypack 7K format and included with the H13066 digital deliverables. Data were processed periodically in CARIS HIPS to evaluate backscatter quality but the processed data is not included with the deliverables.
For data management purposes, the names of multibeam crosslines have been appended with the suffix _XL. This change was made to HIPS files only. The original file names of raw data files (Hypack HSX and 7k) have been retained.CarisHIPS/SIPS10.3.1Chesapeake TechnologySonarWiz6.04.0006NOAA Profile Version 5.6A detailed listing of all data processing software is included in the OPR-J348-KR-17 DAPR.H13066_MB_1m_MLLWCARIS Raster Surface (CUBE)19.05719.167NOAA_1mComplete MBESH13066_MB_1m_MLLW_FinalCARIS Raster Surface (CUBE)19.05719.167NOAA_1mFinalized Complete MBESH13066_SSS_1m_100SSS Mosaic100N/A100% SSSBathymetric grids were created relative to Mean Lower Low Water (MLLW) in CUBE format using Complete Coverage resolution requirements as described in the HSSD.A complete description of the horizontal and vertical control for survey H13066 can be found in the OPR-J348-KR-17 Horizontal and Vertical Control Report (HVCR), submitted under a separate cover. A summary of horizontal and vertical control for this survey follows.Mean Lower Low WaterDauphin Island873-5180Pascagoula874-1533Bay Waveland874-7437TCARIJ348KR2017Rev.tcPreliminaryThe TCARI file J348KR2017Rev.tc was provided with the project instructions and used for sounding correction within the assigned survey area. The primary water level stations experienced no down time during periods of hydrographic survey up to delivery of this report.North American Datum 1983Projected UTM 16NEnglish Turn, LA (293 kHz)The majority of the chart comparisons were performed by comparing H13066 depths to a digital surface generated from electronic navigational charts (ENCs) covering the survey area. A 50-meter product surface was generated from a triangular irregular network (TIN) created from the soundings, depth contours, and depth features for each ENC scale. An additional 50-meter HIPS product surface of the entire survey area was generated from the finalized MBES CUBE surfaces. The chart comparison was conducted by creating and reviewing the resultant difference surface. The chart comparison also included a review of all assigned charted features within the survey area.
The relevant charts used during the comparison were reviewed to check that all US Coast Guard (USCG) Local Notice to Mariners (LNMs) issued during survey acquisition and impacting the survey area were applied and addressed by this survey.US5MS21M40000382017-10-132017-11-29falseIn general, surveyed depths range from 3 feet shoaler to 5 feet deeper than charted on ENC US5MS21M. The greatest differences are almost exclusively along the long finger-like sand waves located south of Petit Bois Pass. Depth difference between H13066 and chart US5MS21Mfile:///P:/NOAA00000028/0600INFO/0670Reports/H13066/Descriptive_Report/SupportFiles/H13066_ChartComp_Band5.pngUS4AL11M80000482017-12-012018-01-11falseIn general, surveyed depths range from 4 feet shoaler to 7 feet deeper than charted on ENCs US4AL11M and US4MS12M. The greatest differences are almost exclusively along the long finger-like sand waves located south of Petit Bois Pass. Depth difference between H13066 and chart US4AL11M and US4MS12Mfile:///P:/NOAA00000028/0600INFO/0670Reports/H13066/Descriptive_Report/SupportFiles/H13066_ChartComp_Band4.pngUS4MS12M80000292017-09-282017-12-20falseComparison for this ENC is included in the previous comparison with ENC US4AL11M.No Maritime Boundary Points were assigned for this survey.The Wreck PA charted near the southwestern corner of the survey area was fully disproved by junction survey H13065. Only partial coverage was obtained by the H13066 survey within the wrecks disproval radius.
The survey area does not contain any charted features labeled as Reported, Position Doubtful (PD), or Existence Doubtful (ED). All other charted features located within the H13066 survey area are portrayed in the FFF. All uncharted features are portrayed in the FFF as surveyed and attributed with the description of ‘New’.One Danger to Navigation (DtoN) report was submitted for this survey. The following DtoN report was submitted:
H13066 Danger to Navigation 01 – December 19, 2017
H13066 DtoN 01 reports two mounds associated with charted pipelines that met feature creation guidelines specified in the HSSD. AHB determined that the features did not warrant continued DtoN submission to the Nautical Data Branch (NDB). These features were also submitted to the Operations Branch project manager and the NOAA Navigation Manager in H13066 Exposed Pipeline Report 1.1. No channels exist for this survey. There are no designated anchorages, precautionary areas, traffic separation schemes, pilot boarding areas, or channel and range lines within the survey limits. The southern limit of the survey area junctions with charted Safety Fairway 166.200.No bottom samples were required for this survey.Shoreline was not assigned in the Hydrographic Survey Project Instructions or Statement of Work.Other than the previously mentioned junction analyses, no other comparisons with prior surveys were conducted.No Aids to navigation (ATONs) exist for this survey.No overhead features exist for this survey.Multiple pipelines are charted within the survey area.
In three areas, a pipeline is exposed on the seabed. The sections of pipeline which are visibly exposed on the seabed were reported as a Non-DTON Seep and Pipeline Report dated December 19, 2017 and are also included in the H13066 FFF as pipeline features. These features were submitted to the processing branch using the Non-DTON process so that the proper authorities could be notified about the condition of the pipelines.
In two areas, burial material created mounds that exceed the feature creation guidelines specified in the HSSD and were reported to AHB on December 19, 2017. AHB determined that these features did not pose an immediate hazard to navigation and did not warrant submission to NDB. The features are also included in the H13066 FFF as obstructions. No other pipelines were identified as exposed during this survey.
No submarine cables or tunnels were charted or located within the H13066 survey area.Two platforms are charted within the survey area. One of the charted platforms was disproved by the survey and is included in the FFF with a description of ‘Delete’. The other charted platform was found to be two interconnected platforms with the primary structure approximately 43 meters from its charted position and the smaller platform approximately 57 meters from the primary platform. The charted platform is included in the FFF with a description of ‘Retain’.No ferry routes or terminals exist for this survey.No abnormal seafloor and/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 insets are recommended for this area.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 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 and Specifications 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.Jonathan L. Dasler, PE, PLS, CHNSPS/THSOA Certified Hydrographer, Chief of Party2018-03-29Jason Creech, CHNSPS/THSOA Certified Hydrographer, Charting Manager / Project Manager2018-03-29Kathleen SchachtMBES Data Processing Manager2018-03-29David T. Moehl, PLS, CHNSPS/THSOA Certified Hydrographer, Lead Hydrographer2018-03-29OPR-J348-KR-17 Data Acquisition and Processing Report2018-03-21