GNSS satellite corrections were received on each vessel using the G2+ carrier signal from the Marinestar Global Correction System maintained by Fugro. Projected UTM 16North American Datum 1983RTXApplanix PosPac MMS was utilized to post process realtime positioning data utilizing Trimble's PP-RTX implementation of Trimble CenterPoint RTX to create a Smoothed Best Estimate of Trajectory (SBET).Low Water Datum 577.5 ft IGLD-1985 L Michigan,HuronERS via VDATUMIn order to reference soundings to Low Water Datum, a VDatum separation model was applied to the QINSy DB files via a separation file in the acquisition software. Mackinaw_ITRF_to_LWD.binAdditional information discussing the vertical or horizontal control for this survey can be found in the accompanying HVCR and DAPR.19 bottom samples were obtained in accordance with section 7.1 of the HSSD 2019 in areas designated by the feature object class springs (SPRING) in the Project Reference File (PRF). Detailed information and images of the bottom samples listed above 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 AX)No new surveys or further investigations are recommended for this area.No Maritime Boundary Points were assigned for this survey.No ferry routes or terminals exist for this survey.No abnormal seafloor and/or environmental conditions exist for this survey.No new insets are recommended for this area.There were 3 charted AtoNs assigned in H13252. 1 AtoN consits of multiple features. Each feature (4 total) was given a unique identifier in the "userid" field of the .000 S-57 file (format 2XXX). Refer to the FFF for determinations of each feature. Note: All AtoNs were included in the number of charted features within section D.1.3. There was 1 charted pipeline assigned in H13252. Per investigation requirements the feature was included in the FFF. The feature was given a unique identifier in the "userid" field of the .000 S-57 file (format 2XXX). Refer to the FFF for determinations of the feature. Note: the pipeline was included in the number of charted features within section D.1.3. Additionally, there is a charted Cable and Pipeline Area in H13252 in which cables and/or pipelines are visible in the MBES data. All visible features are within the charted corridor. Note: these features were not assigned and are not included in the FFF. No overhead features exist for this survey.No present or planned construction or dredging exist within the survey limits.No platforms 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.There were 17 charted features assigned to H13252. The assigned features are retained in the Final Feature File (FFF). Each feature in the FFF has been given a unique identifier in the "userid" field of the .000 S-57 file (format 2XXX). Refer to the FFF for determinations and recommendations of each feature.There were 2 DtoNs found in H13252, and added to the Final Feature File (FFF). Each feature in the FFF has been given a unique identifier in the "userid" field of the .000 S-57 file (format 2XXXX). Refer to the FFF for determinations and recommendations of each feature. The DtoNs were submitted in the following Danger to navigation reports: H13252 DtoN #1 - 42ft Sounding ; H13252 DtoN #2 - 36ft Obstruction.There were 11 new features found in H13252 and added to the Final Feature File (FFF). Each feature was given a unique identifier in the "userid" field of the .000 S-57 file (format 2XXXX). Refer to the FFF for determinations and recommendation of each feature. Note: DtoNs are not included in the number of new features in this section. DtoNs can be found separately in section D.1.5. 242019-10-152019-10-15US4MI51M80000152019-10-012019-07-18US4MI52M80000A chart comparison was conducted for H13252 using Qimera and CARIS HIPS and SIPS. Contours and soundings were compared against the largest scale ENC US4MI51M to accomplish the chart comparison. This ENC does not cover the entire survey of H13252 and therefore ENC US4MI52M was included to complete the chart comparison. The methods and results of the comparison are detailed below. Contour Comparison Method: Using the 2 meter CUBE weighted Dynamic Surface, the 6, 12, 18, 24 and 30 foot contours were generated in Qimera and displayed against the charted contour. Additionally, the 2 meter CUBE weighted Dynamic Surface was viewed by a custom color band range based on the contour intervals (6ft, 12ft, 18ft, 24ft, 30ft). The results of the comparison are described below, followed by 1-2 images of example areas. Sounding Comparison Method: Using the same 2 meter CUBE weighted Dynamic surface, soundings were generated in CARIS HIPS and SIPS. Soundings were displayed against the charted soundings and a visual comparison was made. The results of the comparison are described below, followed by 1-2 images of example areas.metersUTCNavigable AreaAll times are UTC. The purpose of this survey is to update existing NOS nautical charts. H13252 will cover approximately 40 square nautical miles in the West Straits of Mackinac, MI. SUB CONSULTANT: Geodynamics LLC, 310A Greenfield Dr., Newport, NC 98570Any 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 16N, LWD. All references to other horizontal or vertical datums in this report are applicable to the processed hydrographic data provided by the field unit.2019-06-192019-09-032019Atlantic Hydrographic BranchMultibeam Echo Sounder BackscatterMultibeam Echo SounderDavid Neff, ACSM C.H.2019-05-15eTracStraits of Mackinac, MILake Huron; Lake MichiganOPR-X388-KR-19MichiganNo bottom samples or overboard operations (ex. CTD) in cabled or the Enbridge Pipeline areas. Also be careful of Great Lakes Acoustic Telemetry Observation System (GLATOS) stations to the west of the bridge.The GLATOS stations are included in the PRF as CRANES For Info Only features.120000West Straits of MackinacUnited StatesH13252ContractorSurvey Coveragefile:///Q:/Survey/SENSITIVE_SURVEYS/H13252_X388_KR_19/AHB_H13252/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13252_SurveyCoverage.pngSurvey Coverage Gap 1 in area shallower than the NALL (Helena Shoal) file:///Q:/Survey/SENSITIVE_SURVEYS/H13252_X388_KR_19/AHB_H13252/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13252_SurveyCoverageGAP_HelenaShoal.pngSurvey Coverage Gap 2 in area shallower than the NALL (St Helena Island) file:///Q:/Survey/SENSITIVE_SURVEYS/H13252_X388_KR_19/AHB_H13252/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13252_SurveyCoverageGAP_StHelenaIsland.pngSurvey Coverage Gap 3 in area shallower than the NALL file:///Q:/Survey/SENSITIVE_SURVEYS/H13252_X388_KR_19/AHB_H13252/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13252_SurveyCoverageGAP3.pngThe entire survey is adequate to supersede previous data.Survey H13252 is accurate to International Hydrographic Organization (IHO) Order 1a as required per the HSSD 2019.*Bottom samples for H13252 were acquired on DN 236 (8/25/2019).2019-06-192019-06-202019-06-212019-06-222019-06-232019-06-242019-06-262019-06-272019-06-292019-06-302019-07-012019-07-032019-07-052018-07-062019-07-072019-07-092019-07-102019-07-122019-07-132019-07-142019-07-152019-07-182019-09-022019-09-036.161097.33680000000R/V 505400000000R/V Endeavor109467.5800000000019041.44All waters in survey areaComplete CoverageSurvey coverage was in accordance with the requirements listed above and in the HSSD. Note: There are three coverage gaps in H13252. The coverage gaps are shallower than the Navigable Area Limit Line (NALL). As these gap were shallower than the NALL, they are not identified as holidays. Additionally, it was determined to be unsafe to return to collect full coverage in the NALL as navigation clearance was uncertain. 84.757745.784284.997145.8982eTrac Inc. conducted hydrographic survey operations in the Straits of Mackinac, which included both the western Lake Michigan and the eastern Lake Huron regions. H13252 covers approximately 40 square nautical miles of survey area. 1165 linear nautical miles were acquired during the survey. H13252 is located in the West Straits of Mackinac, MI. Survey was conducted within these limits between June 19, 2019 (DN170) and September 03, 2019 (DN246).The purpose of this survey is to update existing National Ocean Service (NOS) nautical charts. All data were acquired in accordance with the requirements in the Project Instructions and specifications set forth in the Hydrographic Survey Specifications and Deliverables 2019 Edition (HSSD 2019). Survey Limits Overview (light blue area)file:///Q:/Survey/SENSITIVE_SURVEYS/H13252_X388_KR_19/AHB_H13252/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13252_SurveyLimitsOverview.pngSurvey Limits (black line)file:///Q:/Survey/SENSITIVE_SURVEYS/H13252_X388_KR_19/AHB_H13252/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13252_SurveyLimits.png0.6R/V 505100.8R/V Endeavor13.5The R/V 505 is a 10 meter aluminum catamaran equipped with a Universal Sonar Mount (USM) starboard multibeam pole mount. The R/V Endeavor is a 13.5 meter aluminum catamaran equipped with a Universal Sonar Mount (USM) starboard multibeam pole mount.MBESR2Sonic2022MBESR2Sonic2024Positioning and Attitude SystemApplanixPOS MV 320 v5Positioning and Attitude SystemR2SonicI2NSSound Speed SystemAML OceanographicBaseX2Note: R/V 505 utilized a dualhead R2Sonic 2022 multibeam echosounder system, an AML Base.X2 for the sound speed system and a R2Sonic I2NS for the positioning system. R/V Endeavor utilized a dualhead R2Sonic 2024 multibeam echosounder system, an AML Base.X2 for the sound speed system and a POSMV 320 V5 for the positioning system.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 as well as any deviations from the DAPR are discussed in the following sections.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. The beam-to-beam crossline comparison report generated through the Qimera Cross Check tool is included in Separates II. Below is a histogram of the crossline comparison statistics showing IHO Order 1a compliance per beam.H13252 Crossline Comparisonfile:///Q:/Survey/H13252_X388_KR_19/AHB_H13252/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13252_XL_Comparison.pngData Density EvaluationIn 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 Inc. 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 H13252 the following percentages represent the results of the density query: Complete Coverage MBES (Finalized 1m CUBE weighted Dynamic Surface ) = 99.1609% of nodes are composed from at least 5 soundings. Complete Coverage MBES (Finalized 2m CUBE weighted Dynamic Surface ) = 99.7779% of nodes are composed from at least 5 soundings. Complete Coverage MBES (Finalized 4m CUBE weighted Dynamic Surface ) = 99.9665% of nodes are composed from at least 5 soundings.H13252 Finalized 1m Complete Coverage MBES Density Distributionfile:///Q:/Survey/SENSITIVE_SURVEYS/H13252_X388_KR_19/AHB_H13252/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13252_1m_Final_Density.PNGH13252 Finalized 2m Complete Coverage MBES Density Distribution file:///Q:/Survey/SENSITIVE_SURVEYS/H13252_X388_KR_19/AHB_H13252/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13252_2m_Final_Density.PNGH13252 Finalized 4m Complete Coverage MBES Density Distribution file:///Q:/Survey/SENSITIVE_SURVEYS/H13252_X388_KR_19/AHB_H13252/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13252_4m_Final_Density.PNGAll equipment and survey methods were used as detailed in the DAPR.Sonar 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.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 505 and R/V Endeavor casts were applied in QPS QINSy acquisition software at the time of the cast. Surface SVP measured at 1Hz was compared to surface speed from the current profile in realtime. If the surface velocity comparison was in excess of 2m/s at any time during survey operations, a new cast was taken. Surface sound speeds were compared in realtime 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.2019H13254eTrac Inc.W20000The junction comparison was performed using all overlapping data between H13252 and H13254. Below is a histogram of junction comparison statistics showing the difference between the junctioning surfaces and allowable TVU as well as difference statistics. 99.9982% of nodes were within allowable TVU. H13252 - H13254 Junction Comparisonfile:///Q:/Survey/SENSITIVE_SURVEYS/H13252_X388_KR_19/AHB_H13252/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13252_H13254_JunctionTracResults.PNGH13252 - H13254 Difference Statisticsfile:///Q:/Survey/SENSITIVE_SURVEYS/H13252_X388_KR_19/AHB_H13252/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13252_H13254_difftrac.PNG2019H13255eTrac Inc. E5000Note: The junction comparison between H13252 and H13255 will be submitted with the H13255 DR.Depth differences between junctioning surveys were evaluated using the JunctionTrac program, developed in-house by eTrac Inc. 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 2 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.The Qimera-exported BAG uncertainty values originate solely from the standard deviation of the soundings that contributed to each CUBE hypothesis, scaled to the 95% CL, and did not use total propagated vertical uncertainty estimates in the calculation. This is not compliant with NOS HSSD 5.2.1.2.4, where the uncertainty value for the grid node shall be the greater of 1) standard deviation of the soundings contributing to the depth solution, or 2) the a priori computed uncertainty estimate. Furthermore, it is also not in compliance with NOS HSSD 2019 5.1.3, which requires the uncertainty estimates for depth values to support Total Propagated Uncertainty (TPU) estimates. The uncertainty values in the submitted BAGs do not adequately provide enough information to verify if the survey meets uncertainty requirements outlined in NOS HSSD 2019 5.1.3.0.20.05R/V 5050.20.05R/V EndeavorERS via VDATUMStandard deviation and uncertainty 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. The final Bathymetric Attributed Grid (BAG) surface's uncertainty was generated through the NOAA QC Tools and an image of the results is located below. For H13252 the following percentages represent the results of the TPU calculation: Complete Coverage MBES (Finalized 1m CUBE weighted Dynamic Surface in NOAA QC Tools) = 99.5+% of nodes are within the allowable TVU. Complete Coverage MBES (Finalized 2m CUBE weighted Dynamic Surface in NOAA QC Tools) = 99.5+% of nodes are within the allowable TVU. Complete Coverage MBES (Finalized 4m CUBE weighted Dynamic Surface in NOAA QC Tools) = 99.5+% of nodes are within the allowable TVU. H13252 Finalized 1m Complete Coverage MBES TVU Statisticsfile:///Q:/Survey/SENSITIVE_SURVEYS/H13252_X388_KR_19/AHB_H13252/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13252_MB_1m_LWD_Final_tvu_qc.pngH13252 Finalized 2m Complete Coverage MBES TPU Statisticsfile:///Q:/Survey/SENSITIVE_SURVEYS/H13252_X388_KR_19/AHB_H13252/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13252_MB_2m_LWD_Final_tvu_qc.pngH13252 Finalized 4m Complete Coverage MBES TPU Statisticsfile:///Q:/Survey/SENSITIVE_SURVEYS/H13252_X388_KR_19/AHB_H13252/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13252_MB_4m_LWD_Final_tvu_qc.pngNone ExistThere were no other factors that affected corrections to soundings.Backscatter data were collected throughout the survey and are retained in the raw ALL and DB files. Every effort was made in the field to collect quality backscatter data while maintaining the primary mandate of high quality bathymetric data. While no processing or analysis of backscatter was required, eTrac Inc. verified coverage and general quality of the backscatter data collected. A beam intensity window was monitored in Qinsy during acquisition to ensure backscatter data collection. Raw backscatter data were viewed in QPS FMGeocoder to further confirm collection criteria had been met. Shown below is an example of the unprocessed backscatter mosaic from H13252 DN193.Raw Backscatter from R/V Endeavor (DN193)file:///Q:/Survey/SENSITIVE_SURVEYS/H13252_X388_KR_19/AHB_H13252/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13252_Backscatter_DN193_EN.PNGAll data reduction procedures conform to those detailed in the DAPR.All sounding systems were calibrated as detailed in the DAPR.H13252 Delivered 1m CUBE weighted Dynamic Surface Coverage Graphicfile:///Q:/Survey/SENSITIVE_SURVEYS/H13252_X388_KR_19/AHB_H13252/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13252_1m_SurfaceCoverage.PNGH13252 Delivered 2m CUBE weighted Dynamic Surface Coverage Graphicfile:///Q:/Survey/SENSITIVE_SURVEYS/H13252_X388_KR_19/AHB_H13252/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13252_2m_SurfaceCoverage.PNGH13252 Delivered 4m CUBE weighted Dynamic Surface Coverage Graphicfile:///Q:/Survey/SENSITIVE_SURVEYS/H13252_X388_KR_19/AHB_H13252/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13252_4m_SurfaceCoverage.PNGBAGComplete MBESH13252_MB_1m_LWD_FinalNOAA_1m1200.66BAGComplete MBESH13252_MB_2m_LWD_FinalNOAA_2m24018BAGComplete MBESH13252_MB_4m_LWD_FinalNOAA_4m494.7236A 1m, 2m and 4m surface are provided meeting complete coverage MBES with backscatter specifications for H13252. Note: The 4m surface's depth range value was extended past 80 meters to include all of the data in H13252 in order to avoid creating a superfluous 8m surface. Parent surfaces of the 1m, 2m, and 4m surfaces are also provided in the Surfaces_Mosaics Folder in this delivery drive package.Feature Object Catalog, NOAA Profile Version 2019 was used only in CARIS. Qimera was used as the primary processing software, which included feature management.NOAA Profile Version 2019David Neff, C.H.2019-11-21Chief of PartyAs 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.