OPR-D304-FH-16Approaches to Chesapeake BayApproaches to Chesapeake BayNOAA Ship FERDINAND R. HASSLERH12859214 Miles East of Poyner HillNorth CarolinaUnited States400002016LCDR Briana J. WeltonNavigable Area2016-02-032016-02-232016-03-23Multibeam Echo SounderMultibeam Echo Sounder BackscattermetersUniversal Transverse Mercator (UTM)UTCAtlantic Hydrographic BranchNOAASurvey H12859 was conducted in the vicinity of the Approaches to Chesapeake Bay, with a sub-locality of 14 Miles East of Poyner Hill as shown in Figure 1.36.42575.637166666736.199166666775.4991666667H12859 Survey LimitsDR_Images\H12859_Survey_Limits.jpgSurvey Limits were extended to the west to include the portion of H12860. Upon, completion of acquisition on H12859, the field unit continued west and included the data in H12859 for processing efficiency.The purpose of this project is to provide contemporary surveys to update National Ocean Service (NOS) nautical charting products. Survey areas will address 403 SNM, of which 260 SNM are Critical Area and 143 SNM are Priority 1 in accordance with the National Hydrographic Survey Priorities Edition 2012. In addition, this project will improve the chart for traffic navigating the Atlantic Ocean Channel and will support BOEM research in the area.The entire survey is adequate to supersede previous data.Greater than 8 meters water depthComplete Coverage accomplished using either: A) complete coverage MBES depth and backscatter data, or B) 100% SSS coverage with concurrent set line spacing MBES depth and backscatter data.Survey coverage was in accordance with the requirements listed above and in the HSSD.Survey layout for OPR-D304-FH-16 over raster chart 12200.DR_Images\OPR-D304-FH-16_Survey_Area.jpgS25001791.90000074.8001791.90000074.804.2700096.72016-02-232016-02-242016-03-022016-03-052016-03-062016-03-072016-03-082016-03-092016-03-102016-03-112016-03-182016-03-192016-03-222016-03-23Mainscheme survey lines were run with a dual-head multibeam echosounder. Linear nautical miles were calculated using statistics from the port head.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.S25037.73.77NOAA Ship FERDINAND R. HASSLERDR_Images\B1_Hassler_Picture.pngNOAA Ship FERDINAND R. HASSLER (S250), shown in Figure 3, acquired all surveyed soundings during operation for H12859Reson7125MBESApplanixPOS M/V 320 V5Positioning and Attitude SystemHemisphereMBX-4Positioning SystemAMLMicroCTDConductivity, Temperature, and Depth SensorBrooke OceanMVP-200Sound Speed SystemResonSVP-70Sound Speed SystemSeaBirdSBE 19+Conductivity, Temperature, and Depth SensorA geographic plot of crosslines is shown in Figure 4. The crosslines were filtered to reject data greater then 45 degrees from nadir. To evaluate crossline agreement, two 2-meter surfaces were created: one from crossline depths, the other from mainscheme depths. These two surfaces were differenced using CARIS HIPS/SIPS. The 2.3 million nodes have a difference value range from -0.55 meters and 0.45 meters. The statistical analysis of the differences between the mainscheme and crossline surfaces is shown in Figure 6. The average difference between the surfaces is 0.01 meters with a standard deviation of 0.07 meters; Ninety-five percent of nodes agree within +/- 0.13 meters of the mean.Location of crosslines for H12859.DR_Images\H12859_Crossline_Overview.jpgCloseup of area with sound speed refraction in mainscheme coverage.DR_Images\H12859_Crossline_SS_Closeup.jpgH12859 crossline difference statistics: mainscheme minus crosslines.DR_Images\H12859_XL_MS_Diff.png0.010.102ERS via VDATUMS2501.01.00.5Two tidal models were available for water level corrections associated with survey H12859. A discrete tide zone file, produced by CO-OPS for project OPR-B304-FH-16, was provided to the field unit. Additionally, a vertical datum transformation (VDatum) model was delivered to the field unit in the project instructions. All data for survey H12859 were reduced to MLLW via VDatum. This model functioned as a gridded separation model for GPS tide computations with a 0.102 meter uncertainty. Final TPU calculations are derived from the following sources: VDatum separation model, sound velocity (MVP and surface sound velocimeter), HVF uncertainties, and SBET post processed uncertainty. Error data sources applied through CARIS processing software are listed in Figure 7.Image of the error sources applied when computing TPU in Caris HIPSDR_Images\Uncertainty_Sources.jpgTwo junction surveys exists with H12859. The survey H12841 borders the entire eastern edge of the survey and H12858 borders the the majority of the northern edge.H12841400002015NOAA Ship FERDINAND R. HASSLERESurvey H12859 junctions with survey H12841 with nodes overlapping approximately 0 to 270 meters to the east (See Figure 8). The minimum and maximum depth difference between the two surveys is -3.17 meters and 1.01 meters respectively. Of the greater than 1.2 million overlapping nodes, the average difference is 0.09 meters with a standard deviation of 0.08 meters; Ninety-five percent of the differenced surface nodes are within +/- 0.15 meters of the mean, as shown in Figure 11.H12841 Junction Survey.DR_Images\H12841_Junction_Overview.jpgSheet limits not drawn for proper overlap.DR_Images\H12841_Junction_Overlap_Issue1.jpgSheet limits not drawn for proper overlap.DR_Images\H12841_Junction_Overlap_Issue2.jpgDifference surface statistics for H12859 and H12841.DR_Images\H12841_Junction_Diff_Stats.pngH12858400002016NOAA Ship FERDINAND R. HASSLERNSurvey H12859 junctions with survey H12858 with nodes overlapping approximately 45 to 230 meters to the north (See Figure 12). The minimum and maximum depth difference between the two surveys is -0.49 meters and 0.46 meters respectively. Of the greater than six-hundred thousand overlapping nodes, the average difference is -0.07 meters with a standard deviation of 0.07 meters; Ninety-five percent of the differenced surface nodes are within +/- 0.14 meters of the mean, as shown in Figure 13.H12858 Junction Survey.DR_Images\H12858_Junction_Overview.jpgDifference surface statistics for H12859 and H12858.DR_Images\H12858_Junction_Diff_Stats.pngSonar system quality control checks were conducted as detailed in the quality control section of the DAPR.None ExistThere were no conditions or deficiencies that affected equipment operational effectiveness.Sound Speed Refraction ArtifactsSound speed refraction artifacts exist in some areas of H12859 and were particularly prevalent on DN062. Outer beams were manually rejected where data exceeded TVU limits and where sufficient overlap enabled the hydrographer to do so. Example of sound speed refraction on DN062.DR_Images\H12859_Sound_Speed_Refraction_example.jpgAll sound speed profiles plotted for H12859.DR_Images\H12859_SS_Profile_Compare_All.pngThe ray tracing analysis shows DN062 temporarily exceeding uncertainty limits.DR_Images\H12859_SS_Ray_Trace_All.pngA total of 433 sound speed measurements were taken within the boundaries of H12859 (See Figure 17). These sound speed measurements were collected using the MVP-200 on average every 30 minutes occasionally increasing the frequency to less than 10 minutes. Comparisons were made by the survey watch to assess sound speed variation in the water column.Sound speed casts were applied to the data using Nearest in Distance Within Time (NIDWT) of 2 hours except for lines acquired after 1200 UTC on DN078 through DN079 which used NIDWT of 3hrs.H12859 sound speed profile locations.DR_Images\H12859_SS_Overview.jpgAll equipment and survey methods were used as detailed in the DAPR.All data reduction procedures conform to those detailed in the DAPR.All sounding systems were calibrated as detailed in the DAPR.Backscatter was logged in RESON datagram 7008 snippets record in the raw .s7k files. The .s7k file also holds the navigation record and bottom detections for all lines of survey H12859. The files were paired with the CARIS HDCS data, imported, and processed using Fledermaus Geocoder Toolbox (FMGT). The FMGT projects and backscatter mosaic imagery is included in the field submission. The processed mosaic is formated as a geo-referenced tiff image per specifications. The following information is provided as metadata for the processing branch: Backscatter data processing and mosaicing performed in Fledermaus FMGT version 7.5.3. Backscatter data has a histogram range of 10 to -70dB Backscatter data is provided in separate layers broken down by survey vessel hull number and sonar operating frequency. H12859_S250P_400kHz | 4m resolution mosaic | Absorption Coefficient = 100dB/km H12859_S250S_400kHz | 4m resolution mosaic | Absorption Coefficient = 100dB/kmNOAA Profile V_5_4H12859_MB_1m_MLLWCUBE1.016.7730.55NOAA_1mComplete MBESH12859_MB_1m_MLLW_FinalCUBE1.016.7720.00NOAA_1mComplete MBESH12859_MB_2m_MLLWCUBE2.016.7939.48NOAA_2mComplete MBESH12859_MB_2m_MLLW_FinalCUBE2.01839.52NOAA_2mComplete MBESData DensityA density analysis was run to calculate the number of soundings per surface node. The results determined that greater than 99.5% of all nodes contained five (5) or more soundings which meets the data density specifications (See Figure 18 and 19).Data density of the 1-meter finalized surface.DR_Images\H12859_MB_1m_MLLW_Final_Density.pngData density of the 2-meter finalized surface.DR_Images\H12859_MB_2m_MLLW_Final_Density.pngTotal Vertical Uncertainty StandardsPydro's Finalized CSAR QA tool was used to calculate the percentage of nodes which meet total vertical uncertainty (TVU) specifications. The resulting statistical analysis yielded greater than 99.5% of all nodes meet TVU specifications (See Figure 20 and 21). In addition, a custom layer was created for the finalized surface submitted in correlation with H12859. The layer was derived from the difference between the calculated uncertainties of individual nodes and the allowable IHO uncertainty at the coupled node and scaled to a 95% confidence interval.Total vertical uncertainty analysis for the 1-meter finalized surface.DR_Images\H12859_MB_1m_MLLW_Final_TVU_QC.pngTotal vertical uncertainty analysis for the 2-meter finalized surface.DR_Images\H12859_MB_2m_MLLW_Final_TVU_QC.pngHolidaysThirteen (13) holidays exist within the survey survey limits of H12859. One (1) holiday occurs in the 1-meter finalized surface while the remaining twelve (12) occur in the 2-meter finalized surface. Most of the holidays were created after completion of acquisition on the project while rejecting suspect data. Areas around the holidays were inspected for signs of features or shoaling and no navigational dangers appear to exist.A holiday in the 1-meter finalized surface.DR_Images\H12859_1m_Holiday_55_nodes.jpgEight (8) holidays in the 2-meter finalized surface.DR_Images\H12859_2m_Holidays_West.jpgFour (4) holidays in the 2-meter finalized surface.DR_Images\H12859_2m_Holidays_East.jpgAll vertical and horizontal control activities conducted during the course of this survey are fully addressed in the following sections. No separate HVCR is submitted.Mean Lower Low WaterERS via VDATUMD304_VDatum_xyNAD83-MLLW.csarNorth American Datum of 1983 (NAD83)UTM 18NSingle BaseDUCK 3, Duck, NCNCDULOYOLA, Virginia Beach, VALS03CHESAPEAKE LIGHT, Chesapeake Light, VACOVXSingle Base processing was the primary method used for for Post Processed Kinematics (PPK) processing of Applanix TrueHeave data for Smooth Best Estimate of Trajectory (SBET) production. SBET files have been loaded for all lines for survey H12859 and are used to reduce acquired soundings to MLLW via HSD Operations Branch provided separation model.Driver, VA (289 kHz)GPS Tide Vertical OffsetSome small instances of a vertical offset appear in the data with GPS Tides computed. These are likely due to altitude error in the applied SBETs. These errors are too small to pick out for interpolation and are left in the data. The offsets are still well within vertical TVU limits.Example of a vertical offset on DN078 when GPS Tides are applied.DR_Images\H12859_Vertical_Offset_GPSTide.jpgA sounding plot was generated from the 2-meter surface to compare to the charted soundings. The Chart Comparison Tool contained in the QCTools utility in PydroExplorer, was run to compare the soundings extracted from ENCs US4NC31M, US4NC32M, US4NC53M and US3DE01M. The Chart Comparison Tool uses a triangulated irregular network (TIN) to interpolate in between charted soundings and searched for surveyed depths that are shallower than surrounding charted areas. Even when including soundings from all three charts, the overall density of charted soundings is sparse. There are indications of some shoaling in between the charted soundings, however, none that pose any hazard to navigation. See figures 23, 24, and 25 for the output from the Chart Comparison Tool that highlights the shallower areas (the clusters of red cross hairs).Areas indicating shoaling in comparison to charted soundings. Black soundings are from the ENC and RNC. Blue soundings are generated from surveyed depths.DR_Images\H12859_Chart_Comp_N.jpgAreas indicating shoaling in comparison to charted soundings. Black soundings are from the ENC and RNC. Blue soundings are generated from surveyed depths.DR_Images\H12859_Chart_Comp_Mid.jpgAreas indicating shoaling in comparison to charted soundings. Black soundings are from the ENC and RNC. Blue soundings are generated from surveyed depths.DR_Images\H12859_Chart_Comp_S.jpg1220452780000382016-122016-12-242016-12-24Comparison was combined into the ENC/Survey soundings comparison shown section D.1. 1220754880000242014-072016-12-102016-12-10Comparison was combined into the ENC/Survey soundings comparison shown section D.1. 12200526419706512014-052016-12-102016-12-10Comparison was combined into the ENC/Survey soundings comparison shown section D.1. US4NC53M80000272016-10-072016-10-07falseComparison was combined into the ENC/Survey soundings comparison shown section D.1. US4NC32M80000122016-09-232016-09-23falseComparison was combined into the ENC/Survey soundings comparison shown section D.1. US4NC31M80000202016-09-072016-09-07falseComparison was combined into the ENC/Survey soundings comparison shown section D.1. US3DE01M80000172016-01-282016-04-07falseComparison was combined into the ENC/Survey soundings comparison shown section D.1. No Maritime Boundary Points were assigned for this survey.No charted features exist for this survey. One uncharted wreck was found within survey H12859. Information on the wreck is included in the Final Feature File.No Danger to Navigation Reports were submitted for this survey.No shoals or potentially hazardous 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.Seven (7) bottom samples were attempted. Of the seven attempted, five returned with positive samples. and two yielded no samples after three attempts. Per section 7.5 of the 2015 HSSD, the negative samples have been included in the final feature file with NATSUR (nature of surface) attribution of "unknown." Consult the H12859_Final_Feature_File.hob file for more information about the bottom samples in the survey area.Shoreline was not assigned in the Hydrographic Survey Project Instructions or Statement of Work.No prior survey comparisons exist for this survey.One red navigational buoy exists in H12859 but was not assigned. The buoy appeared well positioned visually and is serving it's intended purpose.No overhead features exist for this survey.No submarine features exist for this survey.No ferry routes or terminals exist for this survey.No platforms exist for this survey.No Significant Features 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 then Commanding Officer, LCDR Briana J. Welton's 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 Manual, 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.LCDR Matthew J. JaskoskiCommanding Officer2017-01-31LT Nicholas C. MorganField Operations Officer2017-01-31