2021-09-30Chief of PartyCAPT John Lomnicky2021-09-30Operations OfficerLT Shelley Devereaux2021-09-30Acting Chief Hydrographic Survey TechnicianACHST Simon Swart2021-09-30Sheet ManagerHAST Brent HumphriesAs 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.OPR-P335-FA-21Gulf of AlaskaSouth Coast of Kodiak, AlaskaNOAA Ship Fairweather (S220)NAD83 5Nmeters2021-04-19CAPT John LomnickyMultibeam Echo SounderMultibeam Echo Sounder BackscatterPacific Hydrographic Branch2021-06-082021-07-262021Any 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 5N, MLLW. All references to other horizontal or vertical datums in this report are applicable to the processed hydrographic data provided by the field unit.Navigable Area10000H13460AlaskaUnited StatesLow Cape to Sukhoi Bay1NOAAH13460 NALL not reached due to project time constraints\SupportFiles\NALL not reached.PNGData was not acquired to the survey limits in accordance with the requirements in the Project Instructions and the 2021 NOS Hydrographic Surveys Specifications and Deliverables (HSSD) The Navigable area limit line (NALL) was not acquired due to project time constraints. The extent of coverage is shown in Figure 2.H13460 sheet limits (in red) overlaid onto Chart 16590\SupportFiles\Sheet Limits plus.PNGThe survey area is located in Low Cape to Sukhoi Bay, Kodiak, AK.154.31798888956.8487388889154.54351944456.99215H13460 survey coverage overlaid onto Chart 16590\SupportFiles\Sheet Limits with legend 2.PNGData acquired in H13460 meet multibeam echo sounder (MBES) coverage requirements for complete coverage, as required by the HSSD. This includes crosslines (see Section B.2.1), NOAA allowable uncertainty (see Section B.2.9), and density requirements (see Section B.2.10).The entire survey is adequate to supersede previous data.0023.5906487.804.460000509.540021.73104.300000000FA 2805118.300000000FA 280751.7000000021.7FA 2808213.500000000FA S2202021-07-262021-07-252021-07-242021-07-232021-07-212021-07-202021-06-102021-06-08The marine waters around Alaska’s Kodiak Archipelago are among the most productive in the North Pacific. A combination of freshwater runoff and offshore upwelling makes the nearshore waters home to over one hundred species of marine fish. Located in the southwestern coast of Kodiak Island, Alitak District has an actively managed commercial salmon fishery. The area is heavily fished and upwards of 5,000 people are employed in the fishing and processing pipeline during season (approximately June through September). Despite being ecologically and economically important, nautical charts in the vicinity of Alitak Bay are based on legacy data and were last surveyed in the 1930s. The proposed 36 square nautical mile survey will provide modern bathymetry data for updating National Ocean Service Nautical charting products. This improves maritime safety, as well as support the Seabed 2030 global mapping initiative.The entirety of H13460 was acquired with complete coverage, meeting requirements listed above and in the HSSD. See Figure 3 for an overview of coverage.Complete CoverageAll waters in survey areaPer Section 5.2.2.1.3 of the 2020 Field Procedures Manual no Horizontal and Vertical Control Report has been generated for H13460.Vessel kinematics data were post-processed using Applanix POSPac processing software and RTX positioning methods described in the DAPR. Smoothed Best Estimates of Trajectory (SBET) and associated error (RMS) data were applied to all MBES data in CARIS Hips and SIPS.RTXNorth American Datum 1983During real-time acquisition, all platforms received correctors from the Wide Area Augmentation System (WAAS) for increased accuracies similar to USCG DGPS stations. WAAS and SBETs were the sole methods of positioning for H13460 as no DGPS stations were available for real-time horizontal control.Projected UTM 5OPR-R355-FA-21_ERTDM21_NAD83-MLLW.csarERS via ERTDMERS via ERTDM methods were used as the final means of reducing H13460 to MLLW for submission.Mean Lower Low Water73.3215.19NOAA_VRH13460_MB_VR_MLLWVariable ResolutionComplete MBESCARIS VR Surface (CUBE)73.3215.19NOAA_VRH13460_MB_VR_MLLW_FinalVariable ResolutionComplete MBESCARIS VR Surface (CUBE)The NOAA CUBE parameters defined in the HSSD were used for the creation of all CUBE surfaces for H13460. 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 vary from 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 the 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.QPSFledermaus7.9.0NOAA Profile Version 2021CARISHIPS and SIPS11.3.17There were no conditions or deficiencies that affected equipment operational effectiveness.None ExistCasts were conducted at a minimum of one every four hours during launch acquisition. Casts were conducted more frequently when there was a change in surface sound speed greater than two meters per second. MVP casts on S220 were conducted at an average interval of 179 minutes, guided by observation of the surface sound speed and targeted to deeper areas. All sound speed methods were used as detailed in the DAPR.Overview of H13460 junction surveys\SupportFiles\Junctions H13460 Overview.PNGH13460 junctions with 1 adjacent surveys from this project, H13459 as shown in Figure 6. Data overlap between H13460 and the adjacent survey was achieved. These areas of overlap between surveys were reviewed in CARIS HIPS and SIPS by surface differencing (at equal resolutions) to assess surface agreement. The multibeam data were also examined in CARIS Subset Editor for consistency and agreement. The junction with H13459 is generally within the NOAA allowable uncertainty in their areas of overlap. For all junctions with H13460, a negative difference indicates H13460 was shoaler and a positive difference indicates H13460 was deeper.Difference surface between H13460 (blue) and junctioning survey H13459 (pink)\SupportFiles\Difference surface between H13460 (blue) and junctioning survey H13459 (pink).PNGDifference surface statistics between H13463 and H12680 (VR surface)\SupportFiles\Junction Difference H13460-59 Stats.PNGSurface differencing in CARIS HIPS and SIPS was used to assess junction agreement between the surface from H13460 and the surface from H13459 (Figure 7) The statistical analysis of the difference surface shows a mean of -0.03 meters with 95% of the nodes having a maximum deviation of +/- 0.17 meters, as seen in Figure 8. It was found that 99.5+% of nodes are within NOAA allowable uncertainty.10000E2021NOAA Ship FairweatherH13459Overview of H13460 Crosslines\SupportFiles\Overview of H13460 Crosslines.PNGH13460 crossline and mainscheme difference statistics\SupportFiles\Crossline Diff Stat.PNGCrosslines 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 4). Statistics show the mean difference between the depths derived from mainscheme data and crossline data was -0.02 meters (with mainscheme being deeper) and 95% of nodes falling within +/- 0.18 meters (Figure 5). For the respective depths, the difference surface was compared to the allowable NOAA uncertainty standards (Figure 5). In total, 99.5+% of the depth differences between H13460 mainscheme and crossline data were within allowable NOAA uncertainties.There were no other factors that affected corrections to soundings.None ExistSonar system quality control checks were conducted as detailed in the quality control section of the DAPR.In addition to the usual a priori estimates of uncertainty via device models for vessel motion and ERTDM, real-time and post-processed uncertainty sources were also incorporated into depth estimates of survey H13460. Real-time uncertainties were provided via EM710 and EM 2040 MBES data and Delayed Heave RMS. Follwing 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 POSPac.0.14ERS via VDATUM0.5S22010.5280X (All Launches)2H13460 allowable uncertainty statistics\SupportFiles\H13460 allowable uncertainty statistics.PNGThe surface was analyzed using the HydrOffice QC Tools Grid QA feature to determine compliance with specifications. Overall, 99.5+% of nodes within the surface meet NOAA Allowable Uncertainty specifications for H13460 (Figure 9).NOAA Allowable UncertaintyH13460 data density statistics\SupportFiles\H13460 data density statistics.PNGThe surface was analyzed using the HydrOffice QC Tools Grid QA feature to determine compliance with specifications. Density requirements for H13460 were achieved with at least 99.5+% of surface nodes containing five or more soundings as required by HSSD section 5.2.2.2 (Figure 10).DensityAll equipment and survey methods were used as detailed in the DAPRBackscatter mosaic for H13460 \SupportFiles\Backscatter H13460.PNGBackscatter calibration values\SupportFiles\Backscatter calibration values 2021.PNGRaw 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 7.9.0 . See Figure 11 for a greyscale representation of the complete mosaic. A relative backscatter calibration was performed by the field unit via a backscatter calibration site in order to bring the survey systems on each of the launches into alignment. See Figure 12 for a table of the calibration values entered into the Processing Settings within FMGT. Approximate inter-calibration corrections for offsets between sonar systems were applied to the mosaic. Furthermore, artifacts from lines of data are seen in the backscatter image that do not adversly impact the grid.All data reduction procedures conform to those detailed in the DAPR.All sounding systems were calibrated as detailed in the DAPR.70.4S2204.88.628051.18.628071.18.628081.1EM 2040Kongsberg MaritimeMBESEM 710Kongsberg MaritimeMBESSBE 19plus V2Sea-Bird ScientificConductivity, Temperature, and Depth SensorPOS MV 320 v5ApplanixPositioning and Attitude SystemMVP200AML OceanographicConductivity, Temperature, and Depth SensorSVP 70Teledyne RESONSound Speed SystemSVP 71Teledyne RESONSound Speed SystemThe equipment was installed on the survey platform as follows: S220 utilizes the Kongsberg EM 710 MBES, a POS M/V v5 system for position and attitude, SVP 70 surface sound speed sensors, and AML Oceanographic MVP 200 for conductivity, temperature, and depth (CTD) casts. All launches utilize the Kongsberg EM 2040 MBES, a POS M/V v5 system for position and attitude, SVP 71 surface sound speed sensors, and Sea-Bird SBE 19plus v2 CTDs for conductivity, temperature, and depth casts.Refer to the OPR-P335-FA-21 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.No new ENC scales are recommended for this area.Maritime Boundary Points were assigned for this survey, but were not addressed due to project time constraints. No platforms exist for this survey.No Aids to navigation (ATONs) exist for this survey.No ferry routes or terminals exist for this survey.No abnormal seafloor or environmental conditions exist for this survey.No submarine features exist for this survey.No overhead features exist for this survey.No present or planned construction or dredging exist within the survey limits.H13460 Bottom sample locations\SupportFiles\Bottom Samples H13460.PNG6 bottom samples were acquired in accordance with the project Instructions for survey H13460. All bottom samples were entered in the H13460 Final Feature File. See Figure 13 for a graphical overview of sample locations.Recommended to verify the marine boundry crane and rock features.No shoals or potentially hazardous features exist for this survey.Survey H13460 has 7 new features that are addressed in the H13460 Final Feature File. Of these features, there is 1 new wreck feature and 6 new seabed areas.All assigned charted features are attributed in the Final Feature File.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.1281529US4AK5LM2018-10-112020-03-05