OPR-G309-FH-16Approaches to WilmingtonApproaches to WilmingtonNOAA Ship FERDINAND R. HASSLERH12929653 Miles South of SouthportNorth CarolinaUnited States400002016LCDR Matthew Jaskoski, NOAANavigable Area2016-06-292016-10-232016-11-09Multibeam Echo SounderMultibeam Echo Sounder BackscattermetersUniversal Transverse Mercator (UTM)UTCAtlantic Hydrographic BranchNOAASurvey H12929 was conducted in Long Bay, with a sublocality of 53 miles South of Southport as shown in Figure 1.33.174680555678.069638888933.153676666777.8785419444H12929 Survey LimitsDR Images\H12929_Survey_Limits.pngSurvey limits were acquired in accordance with the Project Instructions and the 2016 HSSD.The purpose of this project is to provide contemporary surveys to update National Ocean Service (NOS) nautical charting products. The project is based on a request from an Atlantic Coast Port Access Route Study conducted by Pacific Northwest National Laboratory at the request of the U.S. Coast Guard to delineate traffic corridors using Automatic Identification Systems (AIS). This project will improve the chart for traffic navigating from Port to Port along the Atlantic Ocean Channel.The entire survey is adequate to supersede previous data.All waters in survey area.Complete Multibeam Coverage with Backscatter. Refer to the 2016 HSSD Section 5.2.2.3. Survey coverage was in accordance with the requirements listed above and in the HSSD.Survey Layout for survey H12929 overlaying RNC 11520.DR Images\H12929_Survey_Layout.pngS2500640.340000029.4700640.340000029.4704.60600057.432016-10-232016-10-242016-10-252016-10-262016-10-272016-11-082016-11-09Mainscheme survey lines were run with a dual-head multibeam echosounder. Linear nautical miles were calculated using statistics from the port sonar 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\FH_S250_Image.bmpNOAA Ship FERDINAND R HASSLER (S250), shown in Figure 3, acquired all surveyed soundings during operations for H12929.ResonSeabat 7125MBESApplanixPOS M/V 320 V5Positioning and Attitude SystemHemisphereMBX-4Positioning SystemAML OceanographicMicroCTDSound Speed SystemODIM Brooke OceanMVP-200Sound Speed SystemResonSVP-70Sound Speed SystemSea-Bird ElectronicsSBE 19plus SeaCATConductivity, Temperature, and Depth SensorThe ratio of crossline to mainscheme mileage was calculated to be 4.6% which is within specifications set forth in Section 5.2.4.3 of the 2016 HSSD. A geographic plot of crosslines is shown in Figure 4. 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 BASE Editor. The two surfaces are in excellent agreement. See Figure 4. Nodes totaling greater than 2.9 million have a difference value range from -1.05 meters and 1.15 meters. The statistical analysis of the differences between the mainscheme and crossline surfaces is shown in Figure 5. The average difference between the surfaces is 0.04 meters with a standard deviation of 0.15 meters; Ninety-five percent of nodes agree within +/- 0.29 meters of the mean. H12929 MBES crossline data overlaid on mainscheme data. The legend represents the difference surface value.DR Images\H12929_Diff_MS_minus_XLs.pngH12929 Crossline difference statistics: mainscheme minus crosslines.DR Images\H12929_XLs_Diff_stats.png0.010.148ERS via VDATUMS25011.5Two (2) tidal models were available for water level corrections associated with survey H12929. A discrete tide zone file, produced by CO-OPS for project OPR-G309-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 H12929 were reduced to MLLW via VDatum. This model functioned as a gridded separation model for GPS tide computations with a 0.148 meter uncertainty. Final TPU calculations are derived from the following sources: VDatum separation model, sound velocity (CTD and surface sound velocimeter), HVF uncertainties, and SBET post processed uncertainty. H12929 junctions with three contemporary surveys. Three of the surveys were conducted by the NOAA Ship Ferdinand R. Hassler; H12895 to the North, and H12894 to the Northwest. The third, survey W00310, was conducted by the NOAA Ship NANCY FOSTER and adjoins H12929 to the East.H12928 was not acquired due to lack of available time on project. W0031002014NOAA Ship NANCY FOSTERESurvey H12929 junctions with its contemporary survey W00310 to the East and their respective nodes overlap by approximately 200 to 500 meters. The minimum and maximum depth difference between the two surveys is -19.6 meters and 8.8 meters, respectively. Of the greater than 1 million nodes, the average difference between is 0.1 meters with a standard deviation of 0.2 meters; 95% of the differenced surface nodes are within +/- .42 meters of the mean, as shown in Figure 7. The H12929 data were inspected and no aberrant accepted soundings were found to be included in the final grid. At the time of junction analysis surfaces from W00310 were in a preliminary processing and QC state, and may have contained spurious depth spikes leading to the elevated max/min differences seen during statistical analysis.H12929 and W00310 junction. The legend represents the difference surface values.DR Images\H12929__W00310_Junction.pngDifference Surface Statistics for H12929 and W00310 Junction.DR Images\H12929_W00310_Diff_Stats.pngH12895400002016NOAA Ship FERDINAND R. HASSLERNSurvey H12929 junctions with its contemporary survey H12895 to the North and their respective nodes overlap by approximately 200 to 300 meters. The minimum and maximum depth difference between the two surveys is -0.89 meters and 1.01 meters, respectively. Of the greater than 1 million nodes, the average difference between is 0.04 meters with a standard deviation of 0.11 meters; 95% of the differenced surface nodes are within +/- .22 meters of the mean, as shown in Figure 9.H12929 and H12895 Junction. The legend represents the difference surface values.DR Images\H12929__H12985_Junction.pngDifference Surface Statistics for the H12929 and H12895 junction.DR Images\H12929__H12985_Diff_Stats.pngH12894400002016NOAA Ship FERDINAND R. HASSLERNWSurvey H12929 junctions with its contemporary survey H12894 to the northwest. Because minimal overlap occurs between these two surveys, statistical analysis of common nodes was deemed unwarranted by the field hydrographer.Sonar 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.SBET AnomalyA vertical offset of up to 0.5 meters can be seen in the data collected on DN299 when comparing the port and starboard RESON data (lines 2016_2991706 Port and 2016_2991706 Starboard). The vertical offset is not seen when the data are reduced to chart datum via discrete zoning. The oscillations in the vertical solution are within the TVU specifications for the depth of the area.Example of SBET anomalyDR Images\SBET_DN299_issue_GPS.pngSBET corresponding to survey lines in figure 10DR Images\SBET_DN299_Port.pngStatic casts were collected (Via Seabird-CTD) approximately every three to four hoursDuring the course of acquisition a total of 23 sound speed measurements were collected via CTD-Seabird. Sound speed corrections were applied in CARIS HIPS/SIPS using the Nearest in Distance Within Time selection with a time frequency of 4 hours. Five casts were taken more than 200 meters outside of the survey area due to operational and efficiency constraints of the ship. Overall, cast frequency was appropriate as evidenced via a ray tracing uncertainty analysis identifying casts that exceeded the allowance for refraction as defined in 2016 HSSD Section 5.2.3.5. As shown in Figure 13, which shows the ray tracing uncertainty analysis for all sound speed profiles during H12929. The blue lines represent consecutive cast comparisons, and the red dots represent the allowable vertical uncertainty due to refraction. None on the blue lines rise above the red dots, and therefore do not exceed the allowable uncertainty. As shown, refraction issues never exceed allowable error tolerances.H12929 sound speed profile locations.file:///Q:/2016/OPR-G309-FH-16_Approaches_to_Wilmington/Surveys/H12929/Descriptive_Report/DR%20Images/H12929_CTD_Cast_2.pngSound Speed Profiles for survey H12929DR Images\SVP_plot.pngRay Tracing Uncertainty Check for survey H12929. No casts in the graph exceeded the uncertainty limits shown by the red lines.DR Images\H12929_Ray_Tracing.pngAll 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 H12929. 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 mosaicking performed in Fledermaus FMGT version 7.6.3 using Reson DeTVG plugins where appropriate. 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. H12929_S250_Port_400kHz | 4m resolution mosaic | Absorption Coefficient = 100dB/km H12929_S250_Stbd_400kHz | 4m resolution mosaic | Absorption Coefficient = 100dB/kmNOAA Profile V_5_4H12929_MB_2m_MLLWCUBE230.0748.18NOAA_2mComplete MBESH12929_MB_2m_MLLW_FinalCUBE230.0739.99NOAA_2mComplete MBESH12929_MB_4m_MLLWCUBE430.0946.40NOAA_4mComplete MBESH12929_MB_4m_MLLW_FinalCUBE436.0046.40NOAA_4mComplete MBESData DensityA density analysis was run to calculate the number of soundings per surface node for the 2-meter finalized and the 4-meter finalized surfaces. The results determined that greater than 99.5% of all nodes contained five (5) or more soundings for both surfaces which meets the data density specifications (See Figure 14 and Figure 15 below).Data Density for the 2 meter finalized surface.DR Images\H12929_2m_Final_Density_Stats.pngData Density for the 4 meter finalized surface.DR Images\H12929_4m_Final_Density_Stats.pngTotal Vertical Uncertainty AnalysisPydro's Finalized CSAR QA tool was used to calculate the percentage of nodes which meet total vertical uncertainty specifications for the 2-meter finalized and 4-meter finalized surfaces. The resulting statistical analysis yielded greater than 99.5% of nodes meet TVU specifications for both surfaces (Figure 16 and Figure 17 below).Total vertical uncertainty analysis for the 2 meter finalized surface.DR Images\H12929_2m_Final_TVU.pngTotal vertical uncertainty for the 4 meter finalized surface.DR Images\H12929_4m_Final_TVU.pngHolidayOne (1) holiday exist within the survey limits of H12929. The one (1) holiday occurs in the 2-meter finalized surface. The holiday was 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. The holiday in the 2-meter finalized surface.file:///Q:/2016/OPR-G309-FH-16_Approaches_to_Wilmington/Surveys/H12929/Descriptive_Report/DR%20Images/H12929_holiday.jpgAdditional information discussing the vertical or horizontal control for this survey can be found in the accompanying ERS Checkline and ERS Capability Memo(s).Mean Lower Low WaterERS via VDATUMG309FH16ExpandedProjectArea_xyWGS84-MLLW_geoid12bAll soundings submitted for H12929 have been reduced to MLLW using documented VDatum techniques.World Geodetic System of 1984: WGS84 (G1674)UTM Zone 17 NorthSingle BaseFort Fisher, NCNCFFAll lines acquired between UTC 0500 and UTC 1200 on DN 313, both the port and starboard POSMV units were logging in RTCM DGPS mode instead of the preferred Marinestar GNSS mode. Given the degradation of position quality when in DGPS mode, a single-base station was used for post-processing and to create SBETs in POSPac MMS during this period. The base station used was Fort Fisher, North Carolina (NCFF). Processed bathymetry merged with the Fort Fisher, NC single base SBET and GPS Tide solution were compared to previous data using the MarineStar SBET and GPS Tide solution and were found to be in excellent agreement.3-D GNSS position data were collected by Applanix POS/MV V5 systems utilizing correctors supplied by Fugro Marinestar. Fugro Marinestar is a satellite-based subscription service that improves GNSS derived position accuracies using a Precise Point Positioning (PPP) approach. The POS/MV data was post processed in Applanix POSPac MMS to produce Smoothed Best Estimates of Trajectory (SBETs) and RMS uncertainty files using the method of Post Processed Precise Point Positioning (5P). The resulting SBETs and RMS files were applied in Caris HIPS and SIPS to all data for survey H12931. Refer to the DAPR for technical details.Kensington, SC (292 kHz)Marinestar Subscription LicenseAll data for survey H12929 has been reduced to Mean Lower Low Water (MLLW) using documented VDatum techniques. The Ferdinand R. Hassler is equipped with Applanix POS/MV position and orientation systems on the port and starboard hulls. Both POS/MV systems have been integrated with Fugro's Marinestar service, which provides real-time GPS correctors via satellite. The correctors are derived using a Precise Point Positioning (PPP) approach. The POS/MV data was post-processed in Applanix POSPac MMS to produce Smoothed Best Estimates of Trajectory (SBETs) and RMS uncertainty files using the method of Post Processed Precise Point Positioning (5P). The resulting SBETs and RMS files were applied in CARIS HIPS and SIPS to all data for survey H12929.WGS84 Horizontal DatumThe horizontal datum requirement stated in the 2016 HSSD section 2.1 was given as World Geodetic System of 1984 (WGS84 (G1674). The field unit followed this requirement, however after data acquisition had already begun, Hydrographic Technical Directive #2016-03 was published rescinding this requirement and re-established the horizontal datum requirement to be the North American Datum of 1983 (NAD83). Subsequent email correspondence from the Chief of HSD Operations stated that any survey initiated in the WGS84 horizontal datum may be continued for the duration of the project or sheet.Traditional TidesAll soundings for H12929 are reduced to MLLW using documented VDatum techniques. However, if it is deemed necessary to change the water level reduction method to discrete zoned tides, the following information may be useful. 1) The National Water Level Observation Network (NWLON) station serving as datum control for this survey is Wrightsville Beach, NC (8658163). 2) The verified water level file (8658163.tid) has been loaded for all data in H12929. GPS tides were applied during the final merge process for all data in H12931, as required for ellipsoid-referenced surveys. 3) The final discrete zoning file (G309FH2016_Rev3_CORP.zdf), as provided in the Tide Note in Appendix I, has been loaded for all data in H12929. 4) A request for final approved tides was sent to CO-OPS on December 12, 2016. The final Tide Note was received on December 20, 2016, providing a revised discrete zoning file (G309FH2016_Rev3_CORP.zdf) for project OPR-G309-FH-16 due to the destruction of the original datum control station (8661070 - Springmaid Pier, SC) during Hurricane Matthew (October 8 - 9, 2016).The hydrographer has compared a sounding plot from the surveyed area to the charted soundings. Additionally, a Chart Comparison Tool contained in the QC Tools utility under PydroExplorer was run to compare the most recent large scale ENC (US3SC10M) to processed sounding data and the S-57 Final Feature File. There are no charted contours to compare.11520377432720452013-092016-09-272016-10-08Surveyed soundings from H12929 agree with 11520 charted depths within one fathom.Chart 11520 comparison.DR Images\H12929_Chart_Comparison.pngUS3SC10M432720212016-09-152016-10-06falseSurveyed soundings from H12929 agree with US3SC10M charted depths within one fathom.Zoom showing minor shoaling in the region of 33-05-20 N and 78-01-02 W. Soundings flagged in orange are approximately 1 fathom shallower than currently charted nearby soundings.DR Images\H12929_ENC_Chart_Comparison.pngZoom showing minor shoaling in the region of 33-11-53 N and 77-57-52 W. The 16 fathom sounding highlighted in red is approximately 1 fathom shallower than currently charted nearby soundings.DR Images\H12929_ENC_Chart_Comparison_2.pngNo Maritime Boundary Points were assigned for this survey.No charted features exist for this survey.No uncharted features exist for this survey.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.Five (5) bottom samples were acquired for this survey. All bottom samples were entered in the H12929 Final Feature File. A sixth bottom sample was attempted, but no sample was recovered. This sample was included in the final feature file with NATSUR (Nature of Surface) attribution of "unknown". See final feature file for more information.Bottom Samples for H12929DR Images\H12929_Bottom_Samples.pngShoreline was not assigned in the Hydrographic Survey Project Instructions or Statement of Work.No prior survey comparisons exist for this survey.No Aids to navigation (ATONs) exist for this survey.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 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 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 Jaskoski, NOAAChief of Party2017-03-03LT Nicholas Morgan, NOAAField Operations Officer2017-03-03LCDR Jonathan French; NOAASheet Manager2017-03-12