OPR-R390-KR-23 Approaches to Nome, AK Norton Sound, AK eTrac H13695 3 Complete Coverage Nome Harbor Alaska United States 10000 2023 David Neff, C.H. Basic Hydrographic Survey 2023-03-01 2023-06-06 2023-08-30 Multibeam Echo Sounder Multibeam Echo Sounder Backscatter meters UTC Pacific Hydrographic Branch All times are UTC. The purpose of this survey is to update existing NOS nautical charts. H13695 covers approximately 20 square nautical miles in Norton Sound, Alaska. Any 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 03N, MLLW. All references to other horizontal or vertical datums in this report are applicable to the processed hydrographic data provided by the field unit. CC0-1.0 (NOAA Contractors) CC0-1.0 https://creativecommons.org/publicdomain/zero/1.0/ https://creativecommons.org/publicdomain/zero/1.0/legalcode These data were produced under contract with NOAA and any potential copyright was assigned to NOAA. NOAA waives any potential copyright and related rights in these data worldwide through the Creative Commons Zero 1.0 Universal Public Domain Dedication (CC0). Contractor eTrac conducted hydrographic survey operations in Nome, Alaska. H13695 covers approximately 20 square nautical miles of survey area. 1075.57 linear nautical miles were acquired during the survey. Survey was conducted within these limits between June 6, 2023 (DN157) and August 30, 2023 (DN242). 64.51220030555555 165.58568408333335 64.42991077777778 165.3474205 Survey Limits Overview (light blue area) SupportFiles\H13695_SurveyLimits_Overview.png Survey Limits (black line) SupportFiles\H13695_SurveyLimits.png All data were acquired in accordance with the requirements in the project instructions and specifications set forth in the Hydrographic Survey Specifications and Deliverables 2022 Edition (HSSD 2022). The purpose of this survey is to update existing National Ocean Service (NOS) nautical charts. The entire survey is adequate to supersede previous data. Survey H13695 is accurate to International Hydrographic Organization (IHO) Order 1a as required per the HSSD 2022. All waters in sheet 3 Complete Coverage in accordance with the requirements listed below and HSSD 2022. All waters in survey area Collect a minimum of 13,210 LNMs. Per request of COR, junction area with F00664 was upgraded to survey area that counts towards mileage cap. Survey coverage was in accordance with the requirements listed above and in the HSSD. Survey Coverage SupportFiles\H13695_SurveyCoverage.png Survey Coverage with 3.5m NALL Displayed SupportFiles\H13695_SurveyCoverage_NALL.png R/V Thunder 0.0 493.14 0.0 0.0 0.0 0.0 0.0 39.31 0.0 ASV Quimby 0.0 543.13 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1036.27 0.0 0.0 0.0 0.0 0.0 39.31 0.0 4.15 4 0 0 0 20.0 2023-06-06 2023-06-07 2023-06-08 2023-06-09 2023-06-21 2023-06-23 2023-06-24 2023-06-25 2023-06-27 2023-06-30 2023-07-01 2023-07-02 2023-07-03 2023-07-06 2023-07-07 2023-07-08 2023-07-09 2023-07-10 2023-07-11 2023-07-13 2023-07-16 2023-08-09 2023-08-10 2023-08-16 2023-08-17 2023-08-21 2023-08-22 2023-08-25 2023-08-30 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. R/V Thunder 21.3 0.8 ASV Quimby 7.0 0.56 The R/V Thunder is a 21.3 meter aluminum catamaran equipped with an Universal Sonar Mount High-Tower over-the-side sonar pole. ASV Quimby is a 7 meter Wave Adaptive Modular Vessel (WAM-V) which is an innovative class of watercraft using unique suspension technology to radically improve seagoing capabilities. ASV Quimby is equipped with a custom sonar mount. MBES R2Sonic 2022 MBES R2Sonic 2024 Sound Speed System AML Oceanographic MicroX SV Sound Speed System AML Oceanographic BaseX2 Sound Speed System AML Oceanographic MVP-X Positioning and Attitude System R2Sonic I2NS Positioning and Attitude System Applanix POS MV OceanMaster Note: R/V Thunder utilized a single head R2Sonic 2024 multibeam echosounder system, an AML Micro.X for the surface sound speed system, an AML/eTrac MVP-X and an AML Base.X2 for the sound speed systems, and an Applanix POS MV OceanMaster for the positioning and attitude system. ASV Quimby utilized a single head R2Sonic 2022 MBES, an AML Micro.X for the surface sound speed system, an AML Base.X2 for the sound speed profiles, and a R2Sonic I2NS for the positioning and attitude system. A beam-to-beam statistical analysis was performed using the Cross Check tool in Qimera. A 1 meter Combined Uncertainty and Bathymetric Estimator (CUBE) weighted dynamic surface was created incorporating only the mainscheme lines and excluded crosslines. The Cross Check tool was used to perform the beam-by-beam comparison of the crossline data to the mainscheme surface. Comparisons showed excellent agreement, well above 95% of the allowable TVU. Note: This surface was created for QC only and is not submitted as a surface deliverable. Below is a histogram of the crossline comparison statistics showing IHO Order 1a compliance per beam. H13695 Crossline Comparison SupportFiles\H13695_Plot Image.png ERS via ERTDM 0.13 R/V Thunder 0.05 0.2 ASV Quimby 0.05 0.2 The standard deviation uncertainty and the total vertical uncertainty (TVU) layers of the Dynamic Surface were utilized during data processing to search for features, water column noise, and systematic errors. IHO Order 1a uncertainty specification was met by 100% of the nodes. In Qimera versions beginning in 2.5.1 and beyond, the user has the ability to export the Dynamic Surface to a Bathymetric Attributed Grid (BAG) with the TVU layer. Using this BAG, the percentage of nodes that fell within the TVU specification for each Dynamic Surface was calculated using the NOAA QC tools program.These results are shown in an image below. The TVU was also reviewed using the Colormap Range in the Qimera TVU surface layer. Complete Coverage MBES (Finalized 1m CUBE weighted Dynamic Surface in NOAA QC Tools) = 100% of nodes are within the allowable TVU. H13695 Finalized 4m MBES TVU Statistics SupportFiles\H13695_MB_1m_MLLW_Final.GQv6.tvu_qc.png Depth differences between junctioning surveys were evaluated using the JunctionTrac program, developed in-house by eTrac. For each junction, each CUBE weighted dynamic surface's nodes were exported to an ASCII CSV file where the fields were (Easting, Northing, Depth) for each node. A 4 meter difference surface between the junctioning datasets was also created and exported to an ASCII CSV file where the fields were (Easting, Northing, Diff) for each node. The three ASCII CSV files were then loaded into the JunctionTrac program and junction statistics were computed. A file was also created in this process to locate any nodes from the difference surface that exceed the allowable TVU, which was imported into Qimera and any identified points from JunctionTrac were analyzed. Note: the difference surfaces were created for comparison efforts only and are not submitted as surface deliverables. H13696 10000 2023 eTrac S The junction comparison was performed using all overlapping data between H13695 and H13696. Below is a histogram of junction comparison statistics showing the difference between the junctioning surfaces and allowable TVU as well as difference statistics. 99.4% of nodes were within allowable TVU. H13695 - H13696 Junction Comparison SupportFiles\H13695_H13696_JuncTrac.png H13695 - H13696 Difference Statistics SupportFiles\H13695_H13696_DiffTrac.png F00664 20000 2015 Fairweater S220 Launches 2806 and 2808 N The junction comparison was performed using all overlapping data between H13695 and F00664. Below is a histogram of junction comparison statistics showing the difference between the junctioning surfaces and allowable TVU as well as difference statistics. 83.24% of nodes were within allowable TVU. H13695 completely covers and supersedes F00664. H13695 - F00664 Junction Comparison SupportFiles\H13695_F00664_JuncTrac.png H13695 - F00664 Difference Statistics SupportFiles\H13695_F00664_DiffTrac.png Sonar system quality control checks were conducted as detailed in the quality control section of the DAPR. None Exist There were no conditions or deficiencies that affected equipment operational effectiveness. None Exist There were no other factors that affected corrections to soundings. SVP casts were generally taken every 2 hours. Occasionally casts would exceed a 2 hour frequency, however would never exceed a 4 hour frequency. On R/V Thunder and ASV Quimby casts were applied in QPS Qinsy acquisition software at the time of the cast. Surface sound velocity measured at 1Hz was compared to surface velocity from the sound velocity profile in real-time. If the surface velocity comparison was in excess of 2 m/s at any time during survey operations, a new cast was taken. Surface sound speeds were compared in real-time and profile to profile for each cast on the vessel. Additionally, the processor reviewed profiles in Qimera to remove spurious readings within a cast, compare day-to-day casts, and to check distribution over the surveyed area, in order to better understand trends for efficient acquisition planning. All equipment and survey methods were used as detailed in the DAPR. Data Density Evaluation In order to determine if the density of the data met the specified 5 soundings per node, data density was evaluated using DensityTrac in the AmiTrac program, developed in-house by eTrac. Each finalized CUBE weighted dynamic surface's nodes were exported to a BBH file. The BBH file was then loaded into the DensityTrac program and density statistics were computed. For H13695 the following percentages represent the results of the density query: Complete Coverage MBES (Finalized 1m CUBE weighted Dynamic Surface) = 99.77% of nodes are composed from at least 5 soundings. H13695 Finalized 1m Complete Coverage MBES Density Distribution SupportFiles\H13695_MB_1m_MLLW_Final_Density.png All data reduction procedures conform to those detailed in the DAPR. All sounding systems were calibrated as detailed in the DAPR. Backscatter data were collected throughout the survey and are retained in the raw DB files. Every effort was made in the field to collect quality backscatter data while maintaining the primary mandate of high quality bathymetric data. eTrac verified coverage and general quality of the backscatter data collected daily. A beam intensity window was monitored in Qinsy during acquisition to ensure backscatter data collection. Raw backscatter data were viewed in QPS FMGeocoder (FMGT) to further confirm collection criteria had been met. After MBES data was fully processed and cleaned in Qimera, GSF files were exported and brought into FMGT and processed into backscatter mosaics. Shown below is an example of the raw backscatter mosaic from H13695 DN175 (ASV Quimby). Raw Backscatter from ASV Quimby (DN175) SupportFiles\H13695_DN175_QU_Backscatter.png NOAA Profile Version 2022 Feature Object Catalog, NOAA Profile Version 2022 was used only in CARIS. Qimera was used as the primary processing software. H13695_MB_1m_MLLW_Final BAG 1 0.89 25.33 NOAA_1m Complete MBES H13695_MBAB_2m_TH_400kHz_1of2 MB Backscatter Mosaic 2 N/A Complete MBES H13695_MBAB_2m_QU_400kHz_2of2 MB Backscatter Mosaic 2 N/A Complete MBES A 1m surface is provided meeting complete coverage MBES with backscatter specifications for H13695. Note: The 1m MBES surface's depth range was extended past 20m to include the remaining deeper values beyond 20m to avoid creating superfluous surfaces at a lower resolution. H13695 Finalized 1m CUBE weighted Dynamic Surface Coverage SupportFiles\H13695_SurfaceCoverage_4m.png H13695 Finalized 2m MBAB Mosaic Coverage SupportFiles\H13695_MosaicCoverage_MBAB.png Additional information discussing the vertical or horizontal control for this survey can be found in the accompanying HVCR and DAPR. Mean Lower Low Water ERS via ERTDM OPR-R390-KR-23_Nome_CapeWoolleyToGolovin_AK_ERTDM_2023_NAD83-MLLW.qgfvom In order to reference soundings to Mean Lower Low Water Datum, a separation model was provided by NOAA and was applied to the Qinsy DB files via a .qgfvom separation file in the acquisition software. North American Datum 1983 Projected UTM 3 RTX Applanix PosPac MMS was utilized to post process real time positioning data utilizing Trimble's PP-RTX implementation of Trimble CenterPoint RTX to create a Smoothed Best Estimate of Trajectory (SBET). GNSS satellite corrections were received on each vessel using the G4+ carrier signal from the Marinestar Global Correction System maintained by Fugro. A chart comparison was conducted for H13695 using Pydro CA tools, Qimera, and Caris HIPS and SIPS. Survey data were compared against the largest scale ENCs to accomplish the chart comparisons. US5AK82M, scale: 20000, edition: 8.1, update application date: 3/17/2023, issue date: 3/17/2023 US4AK6RO, scale: 80000, edition: 1, update application date: 10/04/2022, issue date: 10/04/2022 US4AK6QO, scale: 80000, edition: 1.1, update application date: 3/17/2023, issue date: 3/17/2023 Throughout survey operations sounding comparisons between the charted depths and the surveyed depths were analyzed to identify depth discrepancies. Using 1 meter CUBE weighted Dynamic surfaces, soundings were generated in the "Sounding Selection" tab of Pydro CA tools. Soundings were displayed against the charted soundings and a visual comparison was made in Caris HIPS and SIPS. Additionally, potential DtoNs and discrepancies were generated using the "DTM vs Chart" tab of Pydro CA tools. The results were displayed through CA tools and investigated in CARIS HIPS and SIPS and Qimera. An overview image of the generated soundings on each chart is included below. Results of the chart comparison are included in the following sections. Generated Soundings used for Chart Comparison (US5AK82M) SupportFiles\H13695_ChartComparison_US5AK82M.png Generated Soundings used for Chart Comparison (US4AK6RO) \SupportFiles\H13695_ChartComparison_US4AK6RO.png Generated Soundings used for Chart Comparison (US4AK6QO) SupportFiles\H13695_ChartComparison_US4AK6QO.png US5AK82M 20000 8 2023-03-17 2023-03-17 US4AK6RO 80000 1 2022-10-04 2022-10-04 US4AK6QO 80000 1 2023-03-17 2023-03-17 No DTONs exist for this survey. Although shoals were found to have deviated from the charts, it was determined that they were not hazardous to navigation, so a Danger to Navigation Report was not submitted. There were 25 charted features assigned to H13695. 15 of these features were not included in the Final Feature File (FFF) per investigation requirements. Each feature in the FFF has been given a unique identifier in the "userid" field of the .000 S-57 file. Refer to the FFF for determinations and recommendations of each feature. 1 new feature was found in H13695. Each feature in the FFF has been given a unique identifier in the "userid" field of the .000 S-57 file (format 30XXX). Refer to the FFF for determinations and recommendations of each feature. The Nome Harbor has an entrance channel that extends through the outer harbor and into the inner harbor. The USACE reports the channel as 3760 feet (1146 m) in length with variable width and having controlled depths of 10, 12, and 22 feet (3.0, 3.7, and 6.7 meters). Dredging in the Nome harbor was observed in June of 2023. Observed soundings in H13695 show evidence of recent dredging in the harbor and are consistent with the expected channel depths. The dredged channel extends inshore of the NALL and thus was not fully covered by the extents of H13695. No AtoNs were assigned for this survey. Charted AtoNs within the survey area were visually confirmed on station and without damage. No AtoNs were reported to the U.S. Coast Guard. No Maritime Boundary Points were assigned for this survey. 4 bottom samples were obtained in accordance with section 7.1 of the HSSD 2022 in areas designated by the field through discussions with our COR. Detailed information and images of the bottom samples are located in the Final Feature File (FFF). Each bottom sample has been given a unique identifier in the "userid" field of the .000 S-57 file (format CX). 1 overhead cable was assigned for this survey. The cable was charted as crossing the Snake River north of the Inner Harbor and south of the Snake River Bridge. The cable was not found visually. 1 bridge was assigned for this survey. The bridge connects part of Nome Harbor and was visually confirmed. These features were not included in FFF per investigation requirements. No submarine features exist for this survey. No platforms exist for this survey. No ferry routes or terminals exist for this survey. Evidence of seafloor ice scouring and biogenic gas-generated craters (seafloor "pockmarks") are evident in this sheet. Abnormal Seafloor Condition (Ice Scour) SupportFiles\H13695_Abnormal_Seafloor_Conditions_Ice_Scour.png Abnormal Seafloor Condition (Pockmarks) SupportFiles\H13695_Abnormal_Seafloor_Conditions_Pockmarks.png Annual maintenance dredging occurs at the Port of Nome to maintain the Entrance Channel, Basin, and Sediment Trap. The Port of Nome is also undergoing construction to enlarge and deepen the outer harbor. Dredging for placer gold deposits in submerged beach ridges occurs within H13695. Rectangular dredge scars up to 2m deep with surface areas up to 0.2 square kilometers are present in the seafloor south and west of the harbor in water depths ranging from 7 to 21 meters. Mining related dredging scars in H13695 SupportFiles\H13695_Dredging.png No new surveys or further investigations are recommended for this area. No new ENC scales 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 CUBE surfaces, 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. David Neff, C.H. Chief of Party 2023-12-04