Pacific Hydrographic BranchAny 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 AreametersMultibeam Echo Sounder BackscatterMultibeam Echo Sounder2019-06-212019-05-11UTC20192019-04-01Benjamin K. Evans, CAPT/NOAANOAAUgak Bay7United StatesAlaska40000H13110East Coast of Kodiak Island, AlaskaOPR-P136-RA-19NOAA Ship Rainier (S221)Kodiak Island, AlaskaNo Maritime Boundary Points were assigned 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.US4AK5OM2019-08-178false2019-08-17800000A comparison was made between H13110 derived contours and ENC US4AK5OM with the following results. H13110 3-fathom and 10-fathom contours were generally inshore of the charted ENC depth curves. As noted below, many ledges extend farther out on the ENCs than their actual positions. SupportFiles\Chart Comparison 1.pngENC US4AK5OM overlaid with H13110 contours. SupportFiles\Chart Comparison 2.pngENC US4AK5OM overlaid with H13110 contours showing discrepancies between charted depth curves and survey data. SupportFiles\Chart Comparison 3.pngENC US4AK5OM overlaid with H13110 contours showing discrepancies between charted depth curves and survey data. No charted features with the label PA,ED,PD,or REP exist for this survey. No new navigationally significant features were detected that were not included in the H13110 Final Feature File or elsewhere in this report.Four bottom samples were investigated for this survey; the results are included in the H13110 Final Feature File submitted with this report. In many instances charted ledges extend past their positions identified during shoreline acquisition. SupportFiles\Chart Comparison 4.pngUS4AK5OM overlaid with H13110 contours showing mischarted ledge. SupportFiles\Chart Comparison 5.pngUS4AK5OM overlaid with H13110 contours showing mischarted ledge. A comparison was made between H13110 survey data and Electronic Navigational Chart (ENC) US4AK5OM using CUBE surfaces, selected soundings, and contours created in CARIS.No Aids to navigation (ATONs) exist for this survey.No ferry routes or terminals exist for this survey.No new insets are recommended for this area.No present or planned construction or dredging exist within the survey limits.No submarine features exist for this survey.No new surveys or further investigations are recommended for this area.No platforms exist for this survey.Limited shoreline verification was conducted in accordance with applicable sections of NOAA HSSD and FPM using the Project Reference File (PRF) and Composite Source File (CSF) provided with the Project Instructions. In the field, all assigned features that were safe to approach, were addressed as required with S-57 attribution and recorded in the H13110_FFF to best represent the features at chart scale. This file also includes new features found in the field as well as recommendations to update, retain or delete assigned features. Three assigned rocks were investigated with single beam echo sounder. During acquisition no sign of the rocks were detected, however equipment misconfiguration of the SBES at the time of the survey rendered the data unusable for determining a least depth on the rocks with sufficient confidence. Visual observations and recommendations on the rocks are included in the final feature file. The height of one assigned feature was unable to be obtained via LiDAR. The rock was awash at the time of observation. The tidal adjustment of a feature approximately 59m to the SE observed at approximately the same time was used to obtain the raw height. Visual observations and recommendations on the rock are included in the final feature file. No abnormal seafloor and/or environmental conditions exist for this survey.No overhead features exist for this survey.Additional information discussing the vertical or horizontal control for this survey can be found in the accompanying DAPR.P136RA2019_ERTDM_NAD83-MLLW.csar; P136RA2019_ERTDM_NAD83-MHW.csarERS via ERTDMMean Lower Low WaterPrecise Positioning-Real Time Extended (PP-RTX) processing methods were used in Applanix PosPac MMS 8.3 software to produce SBETs for post-processing horizontal correction.SBET Processing MethodProjected UTM 5The Wide Area Augmentation System (WAAS) was used for real-time horizontal control during data acquisition.North American Datum 1983RTXSamuel F. Greenaway CDR/NOAA2020-03-03Chief of PartyHadley A. Owen, LT/NOAA2020-03-03Field Operations OfficerJames B. Jacobson2020-03-03Chief Survey TechnicianAmanda M. Finn2020-03-03Senior Survey TechnicianThe 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.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.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.On day number 132 (May 12, 2019) the POSMV file for vessel S221 was incorrectly set up, resulting in no delayed heave being logged. Therefore real-time heave was applied. As the data in question was acquired via S221 (less subject to the effects of heave) on a relatively calm day, and delayed heave is a post processed element, it was determined that no additional error was induced. S221 Logging of Delayed HeaveOn day number 162 (June 11, 2019) launch 2801 experienced a poor GPS solution from inadequate satellite constellation due to terrain blockage (mountains) in a SW portion of the survey area. As a result the processed SBET was approximately 4 meters offset from adjacent lines. The Pydro AutoQC tool was used to interpolate over the affected area, and a new SBET was created and applied, resolving the issue. The affected line was 0004_20190611_171953_2801_300A_162. SBET - Lack of solution status near a steep elevationSupportFiles\SBET Issue.pngApproximate 4m offset in portion of data acquired by 2801 on DN 162. SupportFiles\SBET Resolution.pngAffected SBET area after SBET interpolation. Total Propagated Uncertainty (TPU) values for survey H13110 were derived from a combination of fixed values for equipment and vessel characteristics, as well as from assigned values for sound speed uncertainties. The uncertainty for the Ellipsoidally Referenced Tidal Datum Model (ERTDM) used to reduce data to the ellipse was determined to be 0.15 meters based on a conservative modeling of uncertainty for the separation model. Please see Appendix A Supplemental Correspondence for more details. ERTDM is synonym to what was formerly know as poor man's VDatum (PMVD). In addition to the usual a priori estimates of uncertainty, some real-time and post-processed uncertainty sources were also incorporated into the depth estimates of this survey. Real-time uncertainties from Kongsberg MBES sonars were recorded and applied in post-processing. Applanix TrueHeave (POS) files, which record estimates of heave uncertainty, were also applied during post-processing. Finally, the post processed uncertainties associated with vessel position and attitude were applied in Caris HIPS using SBET and RMS files generated using POSPac MMS software. Uncertainty values of the submitted finalized grid were calculated in Caris using "Greater of the Two" of uncertainty and standard deviation (scaled to 95%). Grid QA within Pydro QC Tools was used to analyze H13110 Total Vertical Uncertainty (TVU) compliance, a histogram plot of the results is shown below.1.00.05S2213.00.052801, 2802, 2803, 2804ERS via ERTDM0.150The hydrographer has correctly documented the separation model's uncertainty of 0.15m, but has not applied this uncertainty in the data. The hydrographer states, in Table 8 above, that the Sound Speed Uncertainty applied for vessel S221 Measured-MVP values was 1.0m/s, but the processing logs show the applied Measured sound speed uncertainty used for S221 was actually 3.0m/s. SupportFiles\H13110_MB_VR_MLLW_Final.QAv5.tvu_qc.pngPydro derived plot showing TVU compliance of H13110 finalized multi-resolution MBES data. All equipment and survey methods were used as detailed in the DAPR. Pydro QC Tools v. 3.1.1 Detect Fliers was used to find fliers in the finalized variable resolution surface. Detect Fliers parameters included Gaussian Curvature, Adjacent Cells, Edge Slivers, and Isolated Nodes. Flier height was not restricted. Obvious noise was rejected by the hydrographer in Caris subset editor. After data cleaning, Detect Fliers identified 1 fliers. This was investigated and found to be a false positive.Detect FliersSonar system quality control checks were conducted as detailed in the quality control section of the DAPR.Due to poor environmental conditions during the time of the survey, areas in the NW part of the survey. Despite the hydrographer's best efforts to monitor data quality in real time, bubble masses at and below the surface proved to be problematic and caused spreading of the outer beams. To address this issue, the hydrographer rejected the most egregious outer beam soundings obviously in error in an attempt to produce a surface that best represented the sea floor. In some cases, where there was not sufficient overlap between adjacent survey lines, small holidays are now left from cleaning. All examined offsets between survey lines were observed to be within NOAA HSSD standards.Environmental Influence - Outer beam noiseSupportFiles\H13110_NW_Overview.pngImagine showing the main holiday areas in the NW part of H13110.SupportFiles\12-5-2019 10-50-29 AM.pngImage displaying environmental errors existing in NW portion of Survey.SupportFiles\H13110_Noise2.pngImage showing areas where soundings were removed, leaving holidays.RAINIER launch 2801 acquired 13.97 nautical miles of multi beam crosslines across most depth ranges and multiple boat days. Due to operational time constraints, the percentage of crosslines acquired was slightly less than the requirement specified in the HSSD, however the hydrographer deems them adequate for verifying and evaluating the internal consistency of H13110 survey data. Analysis was performed using the Compare Grids function in Pydro Explorer on finalized VR surfaces of H13110 mainscheme only and crossline only data. 99.5% of nodes met allowable uncertainties. SupportFiles\H13110 Xlines.pngH13110 crossline surface overlaid on mainscheme tracklines. SupportFiles\H13110_MB_VR_MLLW_Final-H13110_XL_VR_MLLW_Final_fracAllowErr_Freq.pngPydro derived plot showing node percentage-pass value of H13110 mainscheme to crossline data. SupportFiles\H13110_MB_VR_MLLW_Final-H13110_XL_VR_MLLW_Final_depth_delta.pngPydro derived plot showing absolute difference statistics of H13110 mainscheme to crossline data.There are no junctions associated with this survey. SupportFiles\SVP Locations.pngH13110 sound speed cast locationsOnce every four hours. Fifty five sound speed profiles were acquired for this survey at discrete locations within the survey area at least once every four hours, when significant changes in surface sound speed were observed, or when operating in a new area. Sound speed profiles were acquired using Sea-Bird Scientific SBE 19plus Profiler and Odim Brooke Ocean MVP200. All casts were concatenated into a master file and applied using the "Nearest distance within Time" (4 hours) profile selection method.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.POS MV 320 v5ApplanixPositioning and Attitude SystemEM 2040Kongsberg MaritimeMBESSBE 19plusSea-Bird ScientificConductivity, Temperature, and Depth SensorSVP 70Teledyne RESONSound Speed SystemEM 710Kongsberg MaritimeMBESMVP200ODIM Brooke OceanSound Speed SystemVLP-16Velodyne LiDARLidar SystemEchotrac CV200ODIM Brooke OceanSBESSupportFiles\RA-6 Medley and Rainier.JPGRA-6 (2804) and RAINIER(S221) in Ugak Bay, AKSupportFiles\2701_RA2.jpgRA-2 (2701)1.18.828041.18.828031.18.828021.18.828014.770.4S2210.477.622701All data reduction procedures conform to those detailed in the DAPR. All sounding systems were calibrated as detailed in the DAPR.Raw backscatter data was acquired as .all files logged during MBES operations and subsequently processed by personnel aboard RAINIER. The .GSF files created during processing and one backscatter mosaic per vessel per frequency has been delivered with this report. Backscatter processing procedures are described in the DAPR.SupportFiles\H13110_Backscatter_Chart_Overlay2.pngOverview of H13110 backscatter mosaics (Chart 16593)Submitted surfaces were generated using the NOAA recommended parameters for depth-based (Ranges) Caris variable-resolution bathymetric grids as specified in the 2019 HSSD. Complete MBES0.80105.80H13110_MB_VR_MLLW_finalCARIS VR Surface (CUBE)Variable ResolutionNOAA_VRComplete MBES0.80105.80H13110_MB_VR_MLLWCARIS VR Surface (CUBE)Variable ResolutionNOAA_VRQPS7.8.1Fledermaus Geocoder Tool Box (FMGT)NOAA Extended Attribute Files Version 5_7CARIS11.1HIPS/SIPSPydro QC Tools Grid QA was used to analyze H13110 multibeam echo sounder (MBES) data density. The submitted H13110 variable-resolution (VR) surface met HSSD density requirements as shown in the histogram below.The entire survey is adequate to supersede previous data.SupportFiles\H13110_MB_VR_MLLW_Final.QAv5.density.pngPydro derived histogram plot showing HSSD density compliance of H13110 finalized variable-resolution MBES data. SupportFiles\H13110_Holidays_Edits.pngVR surface showing locations of holidays derived from Pydro. The two holidays in Mainscheme coverage identified in the most NW corner were created during the final day of acquisition; other holidays in the NW corner are the result of insufficient overlap during challenging weather conditions. All locations not directly explained in the image correspond to features.SupportFiles\Holiday between islets.pngHoliday between two islets located in NE section of sheet. On the day of acquisition wave action and hazardous operating conditions made acquiring complete coverage unsafe. Due to time constraints it was not possible to acquire additional coverage. SupportFiles\NE section_NALL_Kelp Line_edited.pngExamples of H13110 NALL determination; the green dashed line indicates assigned sheet limits. This area exhibited large quantities of bull kelp. SupportFiles\Extended coverage_edited.pngH13110 MBES coverage and assigned survey limits. Note area where coverage was extended beyond sheet limits. Data were acquired within the assigned survey limits as required in the Project Instructions and HSSD. As noted above, additional data were acquired opportunistically extending southeast from the sheet limits during ship survey operations. According to the Fisheries of the United States report, Kodiak, Alaska supports the third busiest and fourth richest fisheries port in the United States. In 2017 the port was responsible for 530 million pounds of fish and 152 million dollars of product. Ugak Bay is a well fished area and is adjacent to a coastal route frequently transited by commercial vessels to and from Kodiak. Much of the existing depth data of this area dates back to the 1930s, and is not surveyed to modern standards. This poses a serious risk to life, property and the delicate ecosystem around Kodiak Island. This survey will provide contemporary data to update National Ocean Service (NOS) nautical charting products and generate backscatter data, which will be used in habitat mapping and substrate analysis.The survey area is referred to as H13110, "Ugak Bay" (Sheet 7) in the Project Instructions. The acquired survey area is approximately 22.22 square nautical miles, and encompasses the area assigned in the project instructions as well as a portion of H13109, "Pasagshak Pt" (Sheet 8). The project instructions provided an estimate of 32 square nautical miles. The hydrographer determined that the assigned sheet limits cover an area of 20.66 square nautical miles, and it was determined that the project instructions were incorrect. SupportFiles\Survey outline and coverage1.pngH13110 assigned survey area and coverage (Chart 16593)152.80338557.50152152.53015857.379335Complete multi beam echo sounder (MBES) coverage was acquired to the inshore limit of hydrography, the Navigable Area Limit Line (NALL). Areas where survey coverage did not reach the 3.5-meter depth contour, nor the assigned sheet limits, were due to the survey vessel reaching the extent of safe navigation as shown in the figures below. These areas are characterized as being near shore, subject to dangerous wave action or other hazards such as rocks or thick kelp. A total of 10 holidays are present in survey coverage. Four correspond to features that were investigated during shoreline. Two were created during the final day of acquisition. Due to operational time constraints it was not possible to acquire them once discovered. The remaining four are a cluster located between two investigated features that wave action and hazardous operating conditions made unsafe to acquire. Complete Coverage (Refer to HSSD Section 5.2.2.3)All waters in survey area Acquire backscatter data during all multibeam data acquisition (Refer to HSSD Section 6.2)All waters in survey area00000013.97404.7903.45000000055.430S22100000013.97108.7402801000000018.82028020000000154.3102803000000067.4802804409922.2202019-05-112019-05-122019-05-132019-05-142019-06-112019-06-122019-06-182019-06-192019-06-21