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 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.2020-03-25CDR Briana Hillstrom, NOAACommanding Officer/ Chief of Party2020-03-25LT Calandria DeCastro, NOAAField Operations Officer2020-03-25Joshua HiteshewChief Hydrographic Survey Technician2020-03-25Kevin BrownSheet Manager40000North CarolinaVirginiaH13327United States226 NM Offshore of False Cape, VANOAAOPR-D304-TJ-19NOAA Ship Thomas Jefferson (S222)Approaches to Chesapeake BayChesapeake Bay Approaches2019-10-01Navigable AreaUTCAtlantic Hydrographic Branch2019-11-222019-11-11CDR Briana Hillstrom, NOAAMultibeam Echo Sounder BackscatterSide Scan SonarMultibeam Echo Sounder2019Any revisions to the Descriptive Report (DR) applied during office processing are shown in red italic text. The DR is maintained as a field unit product, therefore all information and recommendations within this report are considered preliminary unless otherwise noted. The final disposition of survey data is represented in the NOAA nautical chart products. All pertinent records for this survey are archived at the National Centers for Environmental Information (NCEI) and can be retrieved via https://www.ncei.noaa.gov/. Products created during office processing were generated in NAD83 UTM 18N, MLLW. All references to other horizontal or vertical datums in this report are applicable to the processed hydrographic data provided by the field unit.metersData were acquired within the following survey limits (Table 1 and Figure 1). The sheet limits for H13326 and H13327 were adjusted for efficiency of acquisition operations and to account for platform availability. The adjusted sheet limits were approved by the Project Manager. (See project correspondence documents, Figure 2, and 3).file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/SurveyLimits_H13327.PNGSurvey H13327 plotted over ENC US3DE01M.file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13327_Sheet_AdjustmentNEw.PNGOriginal sheet limits shown in black as assigned for survey H13326 and H13327.file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13327_Sheet_AdjustmentNEw2.pngThe area highlighted by red box was approved to be assigned to survey H13327 by the project manager.Survey H13327, located 26 NM Offshore of False Cape, Virginia which is located near the Virginia and North Carolina border.36.4974575.30112636.70541775.37187See section A.4 Survey Coverage.The survey is partially adequate to supersede previous data.All waters in survey areaComplete Coverage (Refer to HSSD Section 5.2.2.3)Significant side scan data gaps are present in survey H13327. These data gaps were not observed until the last day of acquisition. After further analysis of the data, the data gaps were observed within data from each day of acquisition. The Klein system, using SonarPro 14.1, was experiencing lag with the following ping collecting data with considerable gaps in coverage with the perception of full coverage. Within Navigation Editor in Caris 10.4, navigation fixes with max distances of 150m between fixes was observed. These areas of increased distances between fixes correlates to the lag that was observed within SonarPro 14.1 during acquisition. (See Figures 4-10 for examples of data gaps in coverage). Refraction was also observed within data from survey H13327 but does not impede the detection of 1m x 1m x 1m features on the sea floor (See Figure 11). file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13327_DN315_DataGap_3.PNGData gap observed in line 315_191110221400 on Julian day number 315.file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13327_DN315_DataGap_4(2).PNGData gap observed in line 315_191110221400 on Julian day number 315.file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13327_DN315_DataGap_5(2).PNGData gap observed in line 315_191110221400 on Julian day number 315.file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13327_DN315_DataGap_6(2).PNGData gap observed in line 315_191110221400 on Julian day number 315.file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13327_DN315_DataGap_7(2).PNGData gap observed in line 315_191110232500 on day number 315.file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13327_DN315_DataGap_8(2).PNGData gap observed in line 315_191111108300 on day number 315.file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13327_DN324_DataGap1(2).PNGData gap observed in line 324_191120010900 on day number 324.file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13327_DN318B_Refraction_2(2).PNGRefraction observed in line 318_B_191114182300on day number 318_B.41.33600802019-11-112019-11-122019-11-142019-11-152019-11-192019-11-202019-11-212019-11-2200000525.27035.086.68000000525.27035.080S222On day 11/22/2019, the ship acquired bottom samples. For a complete discussion, see section D.1.7 Bottom samples.The purpose of this project is to test the DriX Autonomous Surface Vehicle (ASV) while providing contemporary surveys to update National Ocean Service (NOS) nautical charting products. This survey will cover 400 SNM of the approach to Hampton Roads, home to the world’s largest naval base and a port that annually receives over 5,000 arrivals/departures of deep-draft vessels which continually increase in size over time. Within the survey area, there are currently reported depths that are comparable to those of the dredged Thimble Shoal Channel. A vessel ballasted for little-under keel clearance in the channel could risk grounding in the working area if uncharted shoaling has occurred. There are likely substantial changes to the seabed since the most recent partial-bottom coverage survey, which took place in the 1930s. This survey is a critical part of an ongoing, multi-year hydrographic survey covering the approaches to Chesapeake Bay to support the safety of commerce and monitor the habitat and the environmental health of the region.Trimble-RTX service was used with an Applanix POS MVv5 GNSS_INS system to obtain highly accurate ellipsoidally referenced position data to meet ERS specifications for H13327 MBES data.North American Datum 1983The Wide Area Augmentation System (WAAS) was used for real-time horizontal control during data acquisition.Projected UTM 18JTHSurvey H13326 data were acquired in the World Geodetic System of 1984 (WGS 84). Processsing and product creation were completed in North American Datum of 1983 (NAD 83). Mean Lower Low WaterOPR_D304_TJ_19_VDatum_100m_NAD83-MLLW_geoid12b.csarERS via VDATUMAll soundings submitted for H13327 are reduced to MLLW using VDatum techniques as outlined in the DAPR.No Horizontal and Vertical Control Report (HVCR) is required for this survey.No new insets are recommended for this area.No Aids to Navigation (ATONs) exist for this survey.No platforms exist for this survey.No abnormal seafloor and/or environmental conditions exist for this survey.No submarine features exist for this survey.No ferry routes or terminals exist for this survey.No present or planned construction or dredging exist within the survey limits.No overhead features exist for this survey.Shoreline was not assigned in the Hydrographic Survey Project Instructions or Statement of Work.No new surveys or further investigations are recommended for this area.A chart comparison was conducted between survey H13327 and previously charted ENC US3DE01M in accordance with methods outlined in the DAPR.No uncharted features exist for this survey.No channels exist for this survey. There are no designated anchorages, precautionary areas, safety fairways, traffic separation schemes, pilot boarding areas, or channel and range lines within the survey limits. A shoal is present in the middle of H13327 (See section D.1.1). No DTONS were identified.Bottom samples were assigned, investigated, and are included in the Final Feature File. See Figure 36 for a generalized view of H13327's bottom sample locations.file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/BottomSampleLocations_H13327.PNGGeneral location of bottom samples investigated within the sheet limits of H13327.One charted Position Approximate Obstruction was assigned, investigated, disproved, and is included in the Final Feature File. This PA Obstruction was disproved by complete coverage multibeam with a 480m search radius extending from the center of it's charted location (Figure 34-35). Nothing significant was located while conducting the 480m search radius. The hydrographer recommends deleting PA Obstruction from ENC US3DE01M.file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/PA_OBST_APP_Location.PNGGeneral location of the PA obstruction located East of mainscheme data for survey H13327.file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/PA_OBST_Search_Radius.PNGCloser view of PA wreck within H13327 sheet limits, with red circle representing the 480m search radius.No Maritime Boundary Points were assigned for this survey.Sounding sets derived from H13327's bathymetric surfaces generally agreed with soundings from ENC USDE01M. However, one area in the middle of the sheet indicates shoaling with soundings two to five meters shoaler than charted being observed (Figures 31-33). No DTONS were identified.file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13327_Shoal_Overview.PNGOverview of H13327, overlayed on ENC US3DE01M. Black numbers represent charted depths on ENC US3DE01M. The ten targets inside the red polygon highlight the area where a chart discrepancy was identified.file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13327_Shoal_Overview2.PNGBlack numbers represent charted soundings on ENC US3DE01M, red numbers represent soundings that were flagged as possible DTON/Discrepancies within the sounding set that was created from the data acquired on survey H13327.file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13327_Shoal_Overview3.PNGImage of shoaling that was observed within the data for survey H13327, overlayed on ENC US3DE01M. 4197072019-07-10false2019-07-1022US3DE01MAll equipment and survey methods were used as detailed in the DAPR. Raw MBES backscatter was logged as part of the .all file of Kongsberg EM2040 system. Backscatter was processed in QPS Fledermaus GeoCoder Toolbox(FMGT) software and the exported geotiffs are included in the final processed data package. Multibeam acoustic backscatter (MBAB) holidays were observed within data acquired on day 11/21/2019 (Figures 25-29).file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13327_Backscatter.PNGS222's 300kHz multibeam acoustic backscatter at 1m resolution.file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13327_DN325_Backscatter%20holiday_1.PNGS222's multibeam acoustic backscatter holiday on line 0136_20191121_041904_S222_EM2040 on Julian day number 325. Approximate location of 36° 41' 47.85"N, 75° 19' 10.32"W.file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13327_DN325_Backscatter%20holiday_2.PNGS222's multibeam acoustic backscatter holiday on line 0127_20191121_014801_S222_EM2040 on Julian day number 325. Approximate location of 36° 40' 9.47"N, 75° 19' 16.44"W.file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13327_DN325_Backscatter%20holiday_3.PNGS222's multibeam acoustic backscatter holiday on line 0133_20191121_031058_S222_EM2040 on Julian day number 325. Approximate location of 36° 41' 2.07"N, 75° 18' 58.27"W.file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13327_DN325_Backscatter%20holiday_4.PNGS222's multibeam acoustic backscatter holiday on line 0131_20191121_024252_S222_EM2040 on Julian day number 325. Approximate location of 36° 40' 8.81"N, 75° 18' 22.23"W.All sounding systems were calibrated as detailed in the DAPR.All data reduction procedures conform to those detailed in the DAPR.63.44.6S222SSSSystem 5000Klein Marine SystemsMBESEM 2040Kongsberg MaritimeSound Speed SystemThru-Hull SVSValeportSound Speed SystemMVP100AML OceanographicPositioning and Attitude SystemPOS MV 320 v5ApplanixConductivity, Temperature, and Depth SensorSmartXAML OceanographicVessel configurations, equipment operations, data acquisition, and processing were consistent with specifications described in the DAPR.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.Variable ResolutionNOAA_VRH13327_MBES_VR_MLLW38.118.4CARIS VR Surface (CUBE)Complete MBESVariable ResolutionNOAA_VRH13327_MBES_VR_MLLW_Final38.118.4CARIS VR Surface (CUBE)Complete MBES1N/AH13327_SSSAB_1m_455kHz_1of1SSS Mosaic100% SSS1N/AH13327_MBAB_1S222_300kHz_1of1MB Backscatter MosaicMBES BackscatterComplete coverage requirements were met by 100% Side scan sonar coverage with concurrent multibeam as specified under section 5.2.2.3 of the HSSD 2019. All bathymetric grids for H13327 meet density requirements per the HSSD 2019 (Figure 30). See section A.4 Survey Coverage for a complete discussion on side scan coverage.file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13327_density.pngH13327 density statistics.NOAA Profile Version 201940000NOAA Ship FERDINAND R. HASSLER2015SEH12839The southeastern edge of survey H13327 junctioned with survey H12839 (Figure 15). A difference surface comparison was conducted in accordance with procedures outlined in the DAPR. The difference between surveys H13327 and H12839 ranged from -0.69m to 0.85m. The mean was -0.005m and the standard deviation 0.21m (Figure 16). Significant differences between surface nodes were located over highly dynamic areas of the sea floor (Figure 17). file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/Junction_H12839_H13327.PNGSurvey H12839 junctions on the southeastern edge of H13327.file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H12839_H13327_DIFF_STATS.PNGSurvey H13327 and H12839 difference surface comparison statistics.file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/Junction_H12839_H13327_close%20up.pngSurvey H12839 junction dynamic sea floor.40000NOAA Ship FERDINAND R. HASSLER2015SH12840The southern edge of survey H13327 junctioned with survey H12840 (Figure 18). A difference surface comparison was conducted in accordance with procedures outlined in the DAPR. The difference between surveys H13327 and H12840 ranged from -0.77m to 0.88m. The mean was 0.02m and the standard deviation 0.15m (Figure 19).file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/Junction_H12840_H13327.PNGH12840 junctions on the southern edge of H13327.file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H12840_H13327_DIFF_STATS.PNGH13327 and H12840 difference surface comparison statistics40000NOAA Ship FERDINAND R. HASSLER2018NH13094The northern edge of survey H13327 junctioned with survey H13094 (Figure 20). A difference surface comparison was conducted in accordance with procedures outlined in the DAPR. The difference between surveys H13327 and H13094 ranged from -0.58m to 0.88m. The mean was 0.05m and the standard deviation 0.08m (Figure 21).file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/Junction_H13094_H13327.PNGH13094 junctions on the northern edge of H13327.file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13094_H13327_DIFF_STATS.PNGH13327 and H13094 difference surface comparison statistics.40000NOAA Ship THOMAS JEFFERSON2019WH13326The western edge of survey H13327 junctioned with survey H13326 (Figure 22). A difference surface comparison was conducted in accordance with procedures outlined in the DAPR. The difference between surveys H13327 and H13326 ranged from -0.79m to 0.68m. The mean was 0.04m and the standard deviation 0.05m (Figure 23).file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13326_Junction_H13327.pngH13326 junctions on the western edge of H13327.file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13327_MBES_VR_MLLW_Final-H13326_MB_VR_MLLW_Final_depth_delta.pngH13327 and H13326 difference surface comparison statistics.Four contemporary surveys junction with survey H13327 (Figure 14). The following junctions were made with this survey (Table 9):file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/Overview_Junctions.PNGSurvey H13327 limits outlined in black surrounded by all four junctioning surveys outlined in red, plotted over ENC US3DE01M.There were no other factors that affected corrections to soundings.None ExistCasts were conducted at the start of acquisition day, and within four hours of each previous. Sound speed profiles were acquired from S222 in accordance with HSSD 2019 standards using a Rolls Royce Brooke Ocean Moving Vessel Profiler (MVP) 100. MVP casts were conducted from S222 approximately twice an hour. Sound speed was monitored by the survey watch to assess sound speed variation in the water column and conduct casts accordingly. S222 data were corrected by applying sound speed profiles nearest in distance in time (4 hours). All sound speed profile data were concatenated into a master file. A total of 116 sound speed measurements were collected within the survey limits of H13327 with six additional measurements collected outside the data extents (Figure 24). All six of these outside measurements provide data representative of the conditions found within the survey area and are appropriate for use.file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/SVP_Locations.PNGOverview of all SVP casts taken on H13327. The six casts located outside survey limits are highlighted in red.S222 collected 35.08 linear nautical miles of MBES crosslines. A variable resolution (VR) Combined Uncertainty and Bathymetry Estimator (CUBE) surface of VR mainscheme data and a CUBE VR surface of crossline data were differenced. The resulting mean was -0.01m and the standard deviation 0.07m (Figure 12). Visual inspection of the difference surface and statistical analysis of the difference surface revealed no major issues in the data.file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13327_MBES_50cm_XL-H13327_MBES_50cm_MS_depth_delta.pngCrossline-mainscheme comparison statistics for survey H13327.0ERS via VDATUM0.0944.00.2S2222.0The bathymetric surface's uncertainty layer is compliant with HSSD 2019 uncertainty standards. Over 99.5% of all nodes pass uncertainty standards (Figure 13).file:///T:/Survey/H13327_D304_TJ_19/AHB_H13327/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13327_MB_Uncertainty.pngSurvey H13327 uncertainty statistics.Sonar system quality control checks were conducted as detailed in the quality control section of the DAPR.S222 acquired 100% side scan sonar coverage with concurrent multibeam to meet complete coverage requirements on survey H13327, as specified in the project instructions, using a Klein 5000V1 towfish and a Kongsberg EM2040 multibeam system.See section A.4 Survey Coverage.Side scan data gaps