OPR-R365-FA-17F00694AlaskaBering Strait and VicinityApproaches to Yukon River40000KongsbergEM 2040Multibeam Echo SounderODIMCEE PulseVertical Beam Echo SounderNorth American Datum of 1983 (NAD83)Mean Lower Low WaterTCARIUTM Zone 03NOAA Ship FAIRWEATHER2017-07-112017-09-03CDR Mark Van Waes, NOAA2017-10-20This hydrographic survey was acquired in accordance with the requirements defined in the Project Instructions for OPR-R365-FA-17. F00694 is a Reconnaissance Survey, and therefore adheres to Section 5.2.2.5.2 of the HSSD.62.59888165.61347362.408063164.773092Figure 1, Surface from F00694 overlaid onto ENC US4AK96Mfile:///H:/2017_Data/OPR-R365-FA-17_Port%20Clarence/F00694/Survey_Files/DR_Images/Area%20surveyed.pngThis survey was conducted in an effort to provide modern bathymetric data in the mouth of the Yukon River to investigate the effectiveness of leveraging satellite derived bathymetry as a method of updating bathymetry in the river. This survey also provides reconnaissance data on the main channel into the river, an area that has not been surveyed since 1899.The entire survey is adequate to supersede previous data.Please reference Data Acquisition and Processing Report for OPR-R365-FA-17 for a complete description of data acquisition and processing systems, survey vessels, quality control procedures and data processing methods.To verify that all data meet the accuracy specifications as stated in the HSSD, the surface generated from the data was entered into the Grid QA function in PydroXL to determine NOAA allowable uncertainty statistics. It was found that 99.78% of nodes meet NOAA allowable uncertainty specifications for all depths.US4AK98M9000012015-11-092015-11-09falseENC US4A98M contains no sounding data, and therefore a sounding comparison could not be performed between data from F00694 and the ENC. In lieu of a traditional chart comparison, a comparison was done between surveyed data and the satellite derived bathymetry generated by the Office of Coast Survey for this area. See Section H for this analysis.F00694_MB_VR_MLLWCUBE1.0 - 2.00.535.9NOAA_VRReconnaissanceF00694_MB_VR_MLLW_FinalCUBE1.0 - 2.00.535.9NOAA_VRReconnaissanceTCARIVillage Cove, AK9491094A request for final approved tides was sent to N/OPS1 on 9/06/2017. The final tide note was received on 9/15/2017. Vertical offsets exist in the tidally referenced data, likely due to differences in river outflow causing variation in the TCARI model. The largest of these differences were noticed in data near the mouth of the river, where a 4.3 meter deep line crosses a 3.3 meter deep line from the previous day, and a 3.5 meter deep line from the same day (Figure 2).Figure 2, F00694 tidal offsetfile:///H:/2017_Data/OPR-R365-FA-17_Port%20Clarence/F00694/Survey_Files/DR_Images/Tidal_offset.pngDuring real-time acquisition, the survey vessels received correctors from the Wide Area Augmentation System (WAAS) for increased accuracies similar to United States Coast Guard Differential GPS stations. WAAS was the sole method of correcting position data for F00694, as no DGPS stations were available for real-time horizontal control.Acquisition Technique Due to the prevalence of shoals and relative uncertainty of depths in this survey area, the argyle pattern suggested in the Project Instructions was deemed by the field unit to be unsafe and inefficient for the development of the main channel into the Yukon River with the survey launches. The field unit opted to run set lines through the area of greatest AIS traffic at a 50 meter spacing where possible, with further development of areas of interest as determined by the field unit through analysis of the satellite derived bathymetry supplied by the Office of Coast Survey. A large shoal was discovered in the center of the AIS channel east of Kutmuknuk Channel (Figure 3), forcing the field unit to deviate from this set line spacing and explore alternate routes through the channel. Through consult with local traffic and multibeam development of the area, the main channel into the Yukon River was determined to be immediately east of this shoal, with average depths of approximately six meters. In general, the field unit endeavored to maintain spacing between tracklines in an effort to cover as much area as possible in the limited time spent on station. This led to occasional intentional gaps in coverage throughout the surface. Satellite Derived Bathymetry (SDB) The imagery of the satellite derived bathymetry provided for this project proved helpful in operational planning and launch guidance throughout the survey area. See Figure 4 for an overview of the surveyed data overlaid on the SDB image. Visual analysis indicates that in general lighter blue colors tend to correspond with deeper areas, while dark blues and reds tend to correspond with shoals. One example of a deviation from this trend is a charted shoal that was not observed by the field unit (Figure 5). This may be due to the shifting nature of the shoals in the river mouth, rather than an issue with the SDB. Further analysis and comparison between the surveyed data and updated satellite derived data is necessary to fully evaluate the efficacy of leveraging satellite bathymetry as a charting tool in this area.Figure 3, Deviation of main channel from AIS channelfile:///H:/2017_Data/OPR-R365-FA-17_Port%20Clarence/F00694/Survey_Files/DR_Images/survey&ais.pngFigure 4, F00694 surface overlaid on satellite derived bathymetryfile:///H:/2017_Data/OPR-R365-FA-17_Port%20Clarence/F00694/Survey_Files/DR_Images/SDB%20overview.pngFigure 5, Shoal not observed during field operationsfile:///H:/2017_Data/OPR-R365-FA-17_Port%20Clarence/F00694/Survey_Files/DR_Images/disprove_shoal.pngAs 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 Survey Summary 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, Field Procedures Manual, Standing and 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 Summary Report.CDR Mark Van WaesChief of Party2017-10-20LT Damian MandaOperations Officer2017-10-20Sam CandioSheet Manager2017-10-20