OPR-R320-FA-19Cape NewenhamCape NewenhamNOAA Ship FairweatherH13243610 NM West of Cape NewenhamAlaskaUnited States400002019CDR Marc Moser, NOAANavigable Area2019-04-302019-06-062019-07-16Multibeam Echo SounderMultibeam Echo Sounder BackscattermetersUTCPacific Hydrographic BranchThe purpose of this survey is to provide contemporary surveys to update National Ocean Service (NOS) nautical charts. All separates are filed with the hydrographic data. Any revisions to the Descriptive Report (DR) generated during office processing are shown in bold red italic text. The processing branch maintains the DR as a field unit product, therefore, all information and recommendations within the body of the DR are considered preliminary unless otherwise noted. The final disposition of surveyed features is represented in the OCS nautical chart update products. All pertinent records for this survey, including the DR, are archived at the National Centers for Environmental Information (NCEI) and can be retrieved via http://www.ncei.noaa.gov/.NOAAThe survey area is located 10 NM West of Cape Newenham, Alaska.58.657863162.67463158.497217162.384379H13243 sheet limits (in blue) overlaid onto Chart 16305SupportFiles\H13243_SheetLimits.pngData were acquired to the survey limits in accordance with the Project Instructions and the March 2019 NOS Hydrographic Surveys Specifications and Deliverables (HSSD) as shown in Figure 1.The purpose of this hydrographic survey is to update National Ocean Service nautical charting products and support commerce to the northern Bristol Bay region. Capes Newenham and Peirce, Alaska are the southwestern corner of the Togiak National Wildlife Refuge and provide habitat to numerous birds and sea mammals. Ship and barge traffic delivering industrial, consumer, and energy products to the communities of northern Bristol Bay, or continuing north to the Etolin Strait must transit around these capes. Marine commerce is critical for the survival of these western Alaskan communities as they are detached from the rest of the state road system. Legacy hydrographic data in this survey area is extremely sparse and was acquired prior to the 1920s. Updating the nautical charts and accurately charting reported shoals by modern hydrographic means is critical for the future safety of regional commerce, local tanker lightering, emergency response, and the protection of the local wildlife. 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 H13243 meet multibeam echo sounder (MBES) coverage requirements for set line spacing, 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 areaSet Line Spacing MBES at 400 mThe entirety of H13243 was acquired with set line spacing MBES at 400 m, meeting the requirements listed in the HSSD section 5.2.2.4, Option A. See Figure 2 for an overview of coverage.H13243 survey coverage overlaid onto Chart 16305.SupportFiles\H13243_Surface with Scale.pngFA_S2200201.880000016.3900201.880000016.3908.1500041.982019-06-062019-06-072019-06-292019-07-16Refer to the OPR-R320-FA-19 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.S22070.44.8Kongsberg MaritimeEM 710MBESAML OceanographicMVP200Conductivity, Temperature, and Depth SensorTeledyne RESONSVP 70Sound Speed SystemApplanixPOS MV 320 v5Positioning and Attitude SystemS220 utilizes the Kongsberg EM 710 MBES, a POS MV v5 system for positioning and attitude, SVP 70 surface sound speed sensors, and AML Oceanographic MVP 200 for conductivity, temperature, and depth (CTD) casts.Crosslines were collected, processed, and compared in accordance with Section 5.2.4.2 of the HSSD. To evaluate crosslines, a surface generated via data strictly from mainscheme lines and a surface generated via data strictly from crosslines were created. From these two surfaces, a difference surface (mainscheme - crosslines = difference surface) was generated (Figure 3), and is submitted in the Separates II Digital Data folder. As shown in Figure 4, statistics revealed the mean difference between the depths derived from mainscheme data and crossline data was 0.01 m with mainscheme being deeper and 95% of nodes falling within 0.09 m. For the respective depths, the difference surface was compared to the allowable NOAA uncertainty standards. In total, 100% of the depth differences between H13243 mainscheme and crossline data were within allowable NOAA uncertainties.H13243 mainscheme and crosslines comparison surface.SupportFiles\H13243_DR_Images.pngH13243 crosslines comparison statistics.SupportFiles\H13243_MB_4m_MLLW_MS-H13243_MB_4m_MLLW_XL_depth_delta.pngERS via ERTDM0.140.00S220N/A10.5In addition to the usual a priori estimates of uncertainty provided via device models for vessel motion and a Ellipsoidally-Referenced Tidal Datum Model (ERTDM), real-time and post-processed uncertainty sources were also incorporated into the depth estimates of survey H13243. Real-time uncertainties were provided via EM 710 MBES data and Applanix Delayed Heave RMS. Following post-processing of the real-time vessel motion, recomputed uncertainties of vessel roll, pitch, gyro and navigation were applied in CARIS HIPS and SIPS via a Smoothed Best Estimate of Trajectory (SBET) RMS file generated in Applanix POSPac.H13243 junctions with one adjacent survey from this project, H13242 (Figure 5). In an effort to maximize efficiency while on project, data were collected continuously on the same heading on the same day across the initial limits between sheets, utilizing the same positional data and resultant SBET file. Since there was effectively no break in acquisition between where the eastern edge of H13243 meets H13242, data overlap was not achieved. A visual analysis was performed between the adjacent lines in the respective surveys to determine that no blatant biases arose in data processing. Incidentally, overlap was achieved along the northern and southern limits of H13243. This data overlap was reviewed with CARIS HIPS and SIPS by surface differencing (at equal resolutions) to assess surface agreement. The junctions with H13242 are generally within the NOAA allowable uncertainty in their areas of overlap. For the junction with H13243, a negative difference indicates H13243 was shoaler, and a positive difference indicates H13243 was deeper.H13243 and junctioning survey H13242 to the north and the east.SupportFiles\H13243_DR_Junctions_Overview.jpgH13232400002019NOAA Ship FAIRWEATHERNESurface differencing in CARIS HIPS and SIPS was used to assess junction agreement between the surface from H13243 and the surface from H13242 (Figure 6). The statistical analysis of the difference surface shows a mean of 0.03 m with 95% of all nodes having a maximum deviation of +/- 0.11 meters, as seen in Figure 7. It was found that 100% of nodes are within NOAA allowable uncertainty.Difference surface between H13243 (blue) and junctioning surface H13242 (pink).SupportFiles\H13243_DR_Junctions.jpgDifference surface statistics between H13243 and junctioning survey H13242.SupportFiles\H13243_MB_4m_MLLW-H13242_MB_4m_MLLW_depth_delta.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.None ExistThere were no other factors that affected corrections to soundings.4 hoursMVP casts on S220 were conducted at a minimum of one every four hours during acquisition, guided by observation of the surface sound speed and targeted to deeper areas. All sound speed methods were used as detailed in the DAPR.All equipment and survey methods were used as detailed in the DAPR.HolidaysH13243 data were reviewed in CARIS HIPS and SIPS for holidays in accordance with section 5.2.2.4 of the HSSD. No holidays were found for this survey.NOAA Allowable UncertaintyThe surface was analyzed using HydrOffice QC Tools Grid QA feature to determine compliance with specifications. Overall, greater than 99.5% of nodes within the surface meet NOAA Allowable Uncertainty specifications for H13243 (Figure 8).H13243 compliance with uncertainty standards.SupportFiles\H13243_MB_4m_MLLW.QAv5.tvu_qc.pngDensityThe surface was analyzed using the HydrOffice QC Tools Grid QA feature to determine compliance with specifications. Density requirements for H13243 were achieved with at least 99.5% of surface nodes containing five or more soundings as required by the HSSD section 5.2.2.4 (Figure 9).H13243 compliance with density requirements.SupportFiles\H13243_MB_4m_MLLW.QAv5.density.pngAll data reduction procedures conform to those detailed in the DAPR.All sounding systems were calibrated as detailed in the DAPR.Raw backscatter data were stored in the .all file for Kongsberg systems. All backscatter were processed to GSF files, and a floating point mosaic was created by the field unit via Fledermaus FMGT. See Figure 10 for a greyscale representation of the complete mosaic.H13243 backscatter mosaic.SupportFiles\H13243_Backscatter_Mosaic.pngCARISHIPS and SIPS11.1.3QPSFledermaus7.8.10NOAA Profile Version 2019H13243_MB_4m_MLLWCARIS Raster Surface (CUBE)423.046.5NOAA_4mMBES TracklineH13243_MB_4m_MLLW_FinalCARIS Raster Surface (CUBE)423.046.5NOAA_4mMBES TracklineThe NOAA CUBE parameters defined in the HSSD were used for the creation of all CUBE surfaces for H13243. 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 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 surface.Data LogsData acquisition and processing notes are included in the acquisition and processing logs, and additional processing such as final seperation model reduction and sound speed application are noted in the H13243 Data Log spreadsheet. All data logs are submitted digitally in the Separates I folder.Per Section 5.1.2.3 of the Field Procedures Manual (2014 ed), no Horizontal and Vertical Control Report has been generated for H13243.Mean Lower Low WaterTide Buoy 1TBAERS via ERTDMR320FA2019_ERTDM_NAD83-MLLW.csarERS methods were used as the final means of reducing H13243 to MLLW for submission.North American Datum 1983Projected UTM 3RTXVessel kinematic data were post-processed using Applanix POSPac processing software and RTX positioning methods described in the DAPR. Smoothed Best Estimate of Trajectory (SBET) and associated error (RMS) data were applied to all MBES data in CARIS HIPS and SIPS.During real-time acquisition, S220 received correctors from the Wide Area Augmentation System (WAAS) for increased accuracies. WAAS and SBETs were the sole methods of positioning for H13243 as no DGPS stations were available for realtime horizontal control.A comparison was performed between survey H13243 and ENC US4AK86M using a CARIS HIPS and SIPS sounding layer derived from the 4 meter surface. The soundings and contours were overlaid on the chart to visually assess the differences between the surveyed soundings and charted depths and contours. All data from H13243 should supersede charted data. In general, surveyed soundings agree with the charted depths. A full discussion of the comparisons follows in section D.1.1.US4AK86M4000052019-06-252019-06-25falseSoundings from H13243 agree within 1 fathom of charted depths on ENC US4AK86M with the exception of the 16 fathom depth charted in the SE corner of H13243 (Figure 11). The surveyed depth at this location is 23.6 fathoms, exceeding the charted depth by almost 8 fathoms. The charted 20 fathom contour of ENC US4AK86M is consistent with H13243 survey data except where indicated in Figure 11. In the SE portion of H13243 the charted contour, rather than maintaining a NNW-SSE orientation as it does throughout the rest of the sheet limits, changes direction eastwards to exclude the charted depth of 16 fathoms that, as described above, is inconsistent with H13243 survey data. The recommended contour is depicted in Figure 11.Comparison of H13243 soundings (in red) with ENC US4AK86M charted depths (in black). SupportFiles\H13243_ChartComparison.jpgNo Maritime Boundary Points were assigned for this survey.No charted features exist for this survey.No uncharted features exist 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.Four bottom samples were acquired in accordance with Project Instructions for survey H13243 (Figure 12). One bottom sample location was adjusted from project instructions to better encompass the full range of variation in the backscatter mosaic (Figure 12). Two of the four bottom samples, due to a malfunction of the GoPro camera, did not return imagery (Figure 12). All four bottom samples were entered in the H13243 Final Feature File. See Figure 12 for a graphical overview of sample locations. A fifth bottom sample was attempted, however no material or viable imagery was returned after three attempts (Figure 12).H13243 bottom samples overview.SupportFiles\H13243_DR_BottomSamplesOverview.jpgShoreline was assigned in the Hydrographic Survey Project Instructions, however no assigned features 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 platforms exist for this survey.No ferry routes or terminals exist for this survey.There is a shoaling trend to the northwest, in the offshore direction, with shoalest depths of approximately 23 fathoms encountered in the northwest corner of H13243 (Figure 13).H13243 surface annotated to highlight the shoaling trend to the northwest.SupportFiles\H13243_Abnormal_Conditions.jpgNo 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 Specifications and Deliverables, Field Procedures Manual, Project Instructions, and all HSD Technical Directives, except as noted in the Descriptive Report. These data are adequate to supersede charted data in their common areas. This survey is complete and no additional work is required unless otherwise noted herein.CDR Marc Moser, NOAAChief of Party2019-07-25LT Steve Moulton, NOAAField Operations Officer2019-07-25Sam CandioChief Survey Technician2019-07-25ENS Jackson Vanfleet-Brown, NOAASheet Manager2019-07-25