The log boom labeled "PA" in Marguerite Bay was not observed at the time of this survey. No bottom samples were required for this survey.No Maritime Boundary Points were assigned for this survey.The charted soundings and contours of Chart 17422 are identical to those found on ENC US4AK43M. As such, all discussions regarding comparisons between surveyed soundings and charted depths are covered under the ENC US4AK43M discussion below.1017422793342015-0327302017-02-112017-02-07Soundings from H12973 are in general agreement with charted depths on ENC US4AK43M, with most depths agreeing within 3 fathoms as shown in Figure 27. To more accurately visualize trends within these differences, a 16 meter TIN surface was interpolated from the ENC sounding layer. This surface was then differenced with a corresponding 16 meter surface from H12973 and visualized in Figure 28. In this difference surface red colors indicate H12973 was shoaler than ENC US4AK43M, green colors indicate agreement, and blue colors indicate H12973 was deeper than ENC US4AK43M. Statistical analysis of the difference surface shows a mean difference of 27.82m (with H12973 being deeper). Additionally 95% of all nodes have a maximum standard deviation of +/- 73.71m, as shown in Figure 29. The majority of the discrepancies between H12973 and US4AK43M are primarily due to the highly dynamic nature of the seafloor in this area, as well as the the sparse soundings in the area combined with limitations of the TIN creation algorithm. These differences are found in areas deeper than 20 fathoms, and therefore not navigationally significant. Contours from H12973 are in a general agreement with charted contours on ENC US4AK43M as shown in Figure 30. To facilitate electronic navigation, the hydrographer recommends the addition of contours at 5, 15, 20, 25, 30, and 50 fathoms (Figure 31).42017-01-10false2017-01-1079334US4AK43MOverview of H12973 generated soundings in red overlaid onto ENC US4AK43M, with ENC depths shown in whitefile:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/H12973_Soundings.pngDifference surface between H12973 and interpolated TIN surface from US4AK43Mfile:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/ENC_Difference.pngDifference surface statistics between H12973 and interpolated TIN surface from US4AK43Mfile:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/H12973_ENC_TIN_Difference_16m_Diff.pngOverview of H12973 contoursfile:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/H12973_Contours.pngH12973 proposed additional contoursfile:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/proposed_contours.pngNo Danger to Navigation Reports were submitted for this survey. Two shoal areas were discovered during acquisition of bathymetry on H12973. The first area is a new rock in the northern portion of Traitor's Cove over a charted 6.5 fathom sounding (Figure 32). It was unsafe to acquire bathymetry over this rock, and therefore a least depth was not determined. The new rock with unknown height has been incorporated into the H12973 Final Feature File. The second area is a new reef in Port Stewart, extending from the 1.25 fathom sounding to the north and charted rocks to the south, as shown in Figure 33. The extents of the reef are delineated by the bathymetry, as it was unsafe to acquire data over the reef. The new reef has been incorporated into the H12973 Final Feature File.New rock found in Traitor's Covefile:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/Rock_shoal.pngNew reef found in Port Stewartfile:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/Reef_Shoal.pngNo uncharted features exist for this survey.A comparison was performed between survey H12973 and Chart 17422 as well as ENC US4AK43M using CARIS HIPS and SIPS sounding and contour layers derived from the 16 meter combined surface. The contours and soundings were overlaid on the chart to assess differences between the surveyed soundings and the charted depths. The ENC was compared to a 16 meter combined grid by extracting all soundings from the chart and creating an interpolated TIN surface which could be differenced with the combined surface from H12973. All data from H12973 should supersede charted data. In general, surveyed soundings agree with the majority of charted depths. A full discussion of the disagreements follows below. 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.All ATONs located within H12973 were on station and observed to be serving their intended purpose.No Significant Features exist for this survey.No new insets are recommended for this area.The field unit did not submit the scanned boat sheets noted above. H12973 survey limits extended to the NALL (see Section A.1) and all features offshore of the NALL were addressed and attributed in the H12973 Final Feature File. All features inshore of the NALL were attributed in the Final Feature File with the description of "Not Addressed" and remarks of "Retain as charted, not investigated due to being inshore of NALL" as per HSSD Section 7.3.1. Annotations, information, and diagrams collected on boat sheets during field operations are scanned and included in the Separates I Detached Positions folder.No new surveys or further investigations are recommended for this area.No overhead features exist for this survey.No submarine features exist for this survey.No present or planned construction or dredging exist within the survey limits.No platforms exist for this survey.No ferry routes or terminals exist for this survey.No prior survey comparisons were assigned for this survey.H12973 survey coverage (16 meter surface) overlaid onto Chart 17422file:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/H12973_Coverage_Overview.png0029.3000Data was not collected on DNs 293, 302 or 315.2016-10-182016-10-192016-10-242016-10-272016-10-282016-11-082016-11-092016-11-102016-11-112016-11-17000008.87239.87021.28028050000070.9202.78028060000061.1600028080000050.2603.760S2200000057.53014.740The entire survey is adequate to supersede previous data.Data acquired in H12973 meets multibeam echo sounder (MBES) coverage requirements for complete coverage, as required by the 2016 Hydrographic Surveys Specifications and Deliverables (HSSD). This includes crosslines (see Section B.2.1), NOAA Allowable Uncertainty (see Section B.2.10), and density requirements (see Section B.2.11). Additional compliance statistics can be found in the Standards and Compliance Review in Appendix II of this report.All waters in survey areaComplete Coverage. Refer to HSSD Section 5.2.2.3 (Option A)Survey coverage was in accordance with the requirements listed above and in the HSSD.131.615255.66685131.895555.7842833333The survey area is located in Southeast Alaska within the sub-locality of Behm CanalH12973 sheet limits (in red) overlaid onto Chart 17422file:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/H12973_Sheet%20Limits.pngThe purpose of this project is to provide contemporary surveys to update National Ocean Service (NOS) nautical charting products. H12973 addresses approximately 26 SNM of navigationally significant waters.Data were acquired to the survey limits in accordance with the requirements in the Project Instructions and the 2016 Hydrographic Surveys Specifications and Deliverables (HSSD) as shown in Figure 1. In all areas where the 4 meter depth contour or the sheet limits were not met, the Navigable Area Limit Line (NALL) was defined by the inshore limit of safe navigation due to the risks of maneuvering the survey vessel in close proximity to the steep and rocky shoreline. An example of such an area is within Port Stewart as shown in Figure 2. Area where the NALL was defined by the presence of rocksfile:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/H12973_NALL.pngNOAA Ship FAIRWEATHERSoutheast Alaska, Behm CanalSoutheast AlaskaOPR-O393-FA-16NOAAUniversal Transverse Mercator (UTM)UTC +8Navigable Area2016-10-182016-11-17Pacific Hydrographic Branch2016CDR Mark Van Waes, NOAAMultibeam Echo Sounder BackscatterMultibeam Echo Sounder2016-10-04metersThe purpose of this survey is to provide contemporary surveys to update National Ocean Service (NOS) nautical charts. All separates are filed with the hydrographic data. Any revisions to the Descriptive Report (DR) generated during office processing are shown in bold red italic text. The processing branch maintains the DR as a field unit product, therefore, all information and recommendations within the body of the DR are considered preliminary unless otherwise noted. The final disposition of surveyed features is represented in the OCS nautical chart update products. All pertinent records for this survey, including the DR, are archived at the National Centers for Environmental Information (NCEI) and can be retrieved via http://www.ncei.noaa.gov/.AlaskaH12973Registry Instructions400003Behm CanalUnited StatesAll sounding systems were calibrated as detailed in the DAPR.All data reduction procedures conform to those detailed in the DAPR.7.5.3QPSFledermaus FMGT9.1.7Teledyne CARISHIPS and SIPSNOAA Extended Attribute Files version 5.4Data LogsData acquisition and processing notes are included in the acquisition and processing logs, and additional processing such as final tide and sound speed application are noted in the H12973 Data Log spreadsheet. All data logs are submitted digitally in the Separates I folder. Misalignment of the TCARI gridThe TCARI grid provided by HSD OPS was misaligned with the shoreline due to an error in georeferencing the grid (see Figure 26). This caused some areas not covered by the grid to use extrapolated tidal data, however this issue did not prevent the use of ERZT and was resolved with the application of an updated PMVD model. See Appendix II for a copy of this correspondence.Misalignment of the TCARI grid observed in Project OPR-O393-FA-16. The most significant differences occurred in H12971, as shownfile:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/O393%20Behm%20Canal%20PMVD.bmpIn order to prevent visual data gaps between the finalized surfaces, a waiver to extend the 1, 2, 4, 8, and 16 meter surface depths and not submit a 32 meter surface was granted by the Hydrographic Surveys Division Operations Branch, and is located in Appendix II. The modified surface depth ranges are shown in Table 11. All finalized surface depth ranges were extended deeper by 6 times the surface resolution. To determine how much to expand the depth range by, the largest gap in coverage that could be found was measured in CARIS HIPS and SIPS subset editor. The distance of the gap was divided by the resolution of the surface that would cover the gap to determine how many multiples of that resolution it would take to cover that gap. This number was then doubled to ensure that all gaps would be covered resulting in the extension of the surfaces by 6 times their resolution. Additionally, a waiver to extend the 1 meter surface depth shallower to include data collected at high tide above Mean Lower Low Water, i.e. negative numbers, was granted by HSD OPs and is located in Appendix II. The approved 1 meter finalized surface range was -3m to 26m. All surfaces still meet the density and NOAA uncertainty requirements for their expanded ranges as defined by the HSSD. The surfaces have been reviewed where noisy data, or "fliers," were incorporated into the gridded solutions causing the surface to be shoaler or deeper than the true sea floor. Where these spurious soundings caused 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. NOAA_1mH12973_MB_1m_MLLWCUBE1Complete MBESNOAA_1m26-3H12973_MB_1m_MLLW_FinalCUBE1Complete MBESNOAA_2mH12973_MB_2m_MLLWCUBE2Complete MBESNOAA_2m5218H12973_MB_2m_MLLW_FinalCUBE2Complete MBESNOAA_4mH12973_MB_4m_MLLWCUBE4Complete MBESNOAA_4m10436H12973_MB_4m_MLLW_FinalCUBE4Complete MBESNOAA_8mH12973_MB_8m_MLLWCUBE8Complete MBESNOAA_8m20872H12973_MB_8m_MLLW_FinalCUBE8Complete MBESNOAA_16mH12973_MB_16m_MLLWCUBE16Complete MBESNOAA_16m640144H12973_MB_16m_MLLW_FinalCUBE16Complete MBESSound SpeedThroughout the survey area of H12973 there are instances of minor vertical offsets that appear to be due to changes in sound speed through the water column. These offsets are found primarily in smaller bays in Traitor's Cove that have significant freshwater inputs (see Figure 14 for an example in Marguerite Bay), and are generally due to the swath bending downwards, or "frowning". Examination in Subset Editor in CARIS HIPS and SIPS showed the magnitude of these offsets to be within the HSSD specifications for sound speed uncertainty for their respective depths with a negligible impact on the Finalized CUBE surface, and therefore soundings were not rejected. See Figure 15 for a graphical representation of sound speed influence displayed in Subset Editor.H12973 area of vertical offsets due to sound speed influence (10x vertical exaggeration)file:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/H12973_soundspeed.pngH12973 subset of data "frowning" due to sound speed issuesfile:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/H12973_soundspeed_issue.pngHolidaysH12973 data were reviewed in CARIS HIPS and SIPS for holidays in accordance with Section 5.2.2.3 of the HSSD. Two holidays which meet the 3 by 3 node definition were identified via Pydro QC Tools Holiday Finder tool. This tool automatically scans finalized surfaces for holidays as defined in the HSSD and was run in conjunction with a visual inspection of all surfaces by the hydrographer. One holiday in the 1 meter surface is due to acoustic shadowing in a rocky, downward sloping area (Figure 16). This shadow is formed on the side of a feature away from the sonar head, and can occur with rapid drops in the seafloor. This area was examined in CARIS Subset Editor to verify that the least depth was found (Figure 17). The second holiday is in the 2 meter finalized surface, and is due to insufficient coverage over the area (Figure 18). Due to the dynamic nature of the seafloor in this area, the outer beams of each adjacent line were unable to completely ensonify the rock, as shown in Figure 19. Examination in Subset Editor suggests the least depth of this rock was found (Figure 20). Although numerous apparent holidays were flagged by Holiday Finder, all others previously not addressed were examined and determined to be from areas where an adjoining finalized surface covered the gap. An example of an apparent holiday in the 2 meter finalized surface due to the area being shoaler than the depth range for the 2 meter surface and therefore covered by the 1 meter finalized surface in shown in Figure 21.H12973 holiday due to acoustic shadowingfile:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/H12973_1m_Holiday.pngAcoustic shadow holiday viewed in CARIS HIPS and SIPS subset editorfile:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/1m_holiday.pngH12973 holiday due to line spacing on either side of a rockfile:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/2m_holiday.pngLine spacing holiday viewed in CARIS HIPS and SIPS Subset Editor (2D)file:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/2m_holiday_subset.pngLine spacing holiday viewed in CARIS HIPS and SIPS Subset Editor (3D)file:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/2m_3D.pngExample of an apparent holiday covered by an adjacent finalized surfacefile:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/False_holiday.pngNOAA Allowable UncertaintyTo verify that all data meets the accuracy specifications as stated in HSSD Section 5.1.3, a child layer titled "NOAA_Allowable_1" was created for each of the 1 meter, 2 meter, 4 meter, and 8 meter (72-100m), and "NOAA_Allowable_2" for the 8 meter (100-208m) and 16 meter finalized surfaces using the equations stated in Section C.2.1 of the DAPR. These surfaces were then analyzed using the Pydro QC Tools Grid QA feature to determine what percentage of each surface meets specifications. Figure 22 shows an overview of the NOAA Allowable Uncertainty layers for all surfaces. Figure 23 shows the corresponding statistics for each individual surface. H12973 NOAA Allowable Uncertainty overviewfile:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/NOAA_Allowable_Uncertaintay_image.PNGH12973 NOAA Allowable Uncertainty statisticsfile:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/Allowable_Uncertainty_Table_Stats.PNGDensityFinalized surfaces were analyzed using the Pydro QC Tools Grid QA feature and the results are shown in Figure 24 below. Density requirements for H12973 were achieved with 99.40% of finalized surface nodes containing five or more soundings as required be HSSD Section 5.2.2.3. The few nodes that did not meet density requirements are due to sparse data in the outer beams, especially near steep slopes and rocky areas where acoustic shadowing occurred, and at the edges of survey limits as shown in Figure 25. For individual graphs (per surface) of density requirements, see the Standards and Compliance Review located in Appendix II. H12973 density statisticsfile:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/H12973_Density_Tables_Stats.PNGH12973 density overviewfile:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/H12973_Density_Overview.PNGAll equipment and survey methods were used as detailed in the DAPR.None ExistThere were no conditions or deficiencies that affected equipment operational effectiveness.0.5N/A1S2200.52N/A280x (all launches)00TCARI00.10ERS via PMVDIn addition to the usual a priori estimates of uncertainty provided via device models for vessel motion, ERZT, and Poor Man's VDatum (PMVD), real-time and post-processed uncertainty sources were also incorporated into the depth estimates of survey H12973. Real-time uncertainties were provided via EM710 and Teledyne RESON 7125 MBES data, Applanix Delayed Heave RMS, and TCARI tides. Following post-processing of vessel motion, real-time 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 Applanix POSPac.Crosslines were collected, processed, and compared in accordance with Section 5.2.4.3 of the HSSD. To evaluate crosslines, a 16 meter CUBE surface using strictly mainscheme lines and a 16 meter CUBE surface using strictly crosslines were created. From these two surfaces, a difference surface (mainscheme - crosslines = difference surface) was generated at a 16 meter resolution (Figure 4) and is submitted in the Separates II Digital Data folder. Statistics show the mean difference between the depths derived from mainscheme and crosslines to be 0.21 meters (mainscheme being shoaler) with 95% of nodes falling within 5.05 meters (Figure 5). The largest differences were found in the areas in the northern portion of the survey, where depths are in excess of 500 meters. In these areas sound speed issues on the outer beams of the crosslines caused the mainscheme and crossline surfaces to vary by more than 5 meters (See Figure 6). This sound speed issue does not affect the finalized surfaces, and the differences were found to be within the maximum allowable TVU. For the respective depths the difference surface was compared to the allowable NOAA uncertainty standards (Figure 7). In total, 98.75% of the depth differences between H12973 mainscheme and crossline data were within allowable NOAA uncertainties (Figure 8). Overview of H12973 crosslinesfile:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/H12973_MS_XL_Diff_overview.PNGH12973 crossline and mainscheme difference statistics file:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/H12973_XL_Diff_16m.pngH12973 crossline sound speed issuefile:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/H12973_Crossline_Soundspeed.pngDepth differences between H12973 mainscheme and crossline data as compared to NOAA allowable uncertainty standards for the associated depthsfile:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/H12973_NOAAness_XL.pngCrossline surface statistics showing percentage of nodes meeting NOAA allowable uncertaintyfile:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/H12973_NOAAness_XL_StatsTable.PNGSonar system quality control checks were conducted as detailed in the quality control section of the DAPR.Casts were conducted at a minimum of one every four hours during launch acquisition. Casts were conducted more frequently in areas where the influx of freshwater had an effect on the speed of sound in the water column and where 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 22 minutes as recommended by Pydro's CastTime software, which determines optimum cast frequency based on the observed sound speed variations from previous casts. All sound speed methods were used as detailed in the DAPR.H129722016N40000NOAA Ship FAIRWEATHERSurface differencing in CARIS HIPS and SIPS was used to assess junction agreement between the 16 meter combined surface from H12973 and the 16 meter combined surface from H12972, as shown in Figure 10.The statistical analysis of the difference surface shows a mean difference of -0.37 meters with 95% of all nodes having a maximum deviation of +/- 4.52 meters, as seen in Figure 11. Given the significant depths in this area, averaging over 300 meters, this represents strong agreement between the two surveys. In addition, a comparison surface was created between the difference surface and the NOAA allowable uncertainty (see Figure 12). It was found that 97.30% of nodes are within NOAA allowable uncertainty (Figure 13). Difference surface between H12973 (blue) and junctioning survey H12972 (pink)file:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/H12973_H12972_Junction_Diff.PNGDifference surface statistics between H12973 and H12972 (16 meter surface)file:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/H12973_H12972_Difference.pngDifference surface compliance with regard to NOAA allowable uncertainty between H12973 (blue) and junctioning survey H12972 (pink)file:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/H12973_Junction_NOAA_Allowable_uncertainty.PNGDifference surface statistics between H12973 and H12972 showing percentage of nodes meeting NOAA allowable uncertaintyfile:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/H12973_H12972_junction_Table_Uncertainty.PNGH12973 junctions with one adjacent survey from this project, H12972, as shown in Figure 9. Data overlap between H12973 and H12972 was achieved, and areas of overlap between the surveys were reviewed with 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 between H12973 and H12972 is generally within the NOAA allowable uncertainty in the areas of overlap. For this junction a negative difference indicates H12973 was shoaler and a positive difference indicates H12973 was deeper than H12972. Overview of H12973 junction surveyfile:///M:/OPRO393FA16/Surveys/H12973/Compilation/Report/Components/SupportFiles/H12973_junction_overview.PNGThe equipment was installed on the survey platforms as follows: S220 utilizes the Kongsberg EM 710 MBES, SVP 70 surface sound speed sensors, and Rolls Royce MVP for conductivity, temperature, and depth (CTD) casts. All launches utilize Teledyne RESON 7125 SV1 MBES, SVP71 surface sound speed sensors, and Sea-Bird Electronics 19plus CTD casts.MBESTeledyne RESON7125 SV1MBESKongsbergEM710Conductivity, Temperature, and Depth SensorSea-Bird Electronics19plusConductivity, Temperature, and Depth SensorRolls RoyceMVP 200Sound Speed SystemTeledyne RESONSVP 70Sound Speed SystemTeledyne RESONSVP 71Positioning and Attitude SystemApplanixPOS/MV V4Refer to the OPR-O393-FA-16 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.1.1228058.641.1228068.641.1228088.644.88S22070.40Raw backscatter data were logged as .7k files for Teledyne RESON 7125 data. Kongsberg EM710 stores the backscatter in the .all file. The data have been sent to the Pacific Hydrographic Branch for processing. One line per vessel per day of acquisition was processed by the field unit for quality control.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, except as noted in this Descriptive Report. These data are adequate to supersede charted data in their common areas. This survey is complete and no additional work is required unless otherwise noted herein.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.Data Acquisition and Processing Report2017-03-01Horizontal and Vertical Control Report2017-04-17Coast Pilot Report2017-04-17Chief of Party2017-04-18CDR Mark Van Waes, NOAAField Operations Officer2017-04-18LT Bart Buesseler, NOAAChief Survey Technician2017-04-18HCST Douglas BravoSheet Manager2017-04-18HST Sam CandioAcquisition Sheet Manager2017-04-18ENS Mason CarrollMean Lower Low WaterKetchikan9450460The Tide Note is attached.TCARIInitial reduction of acquired data to MLLW was accomplished via tidal means using the Tidal Constituent and Residual Interpolation (TCARI) grid provided by HSD-OPS. Following the successful application of SBETs and a computation of an Ellipsoidally Referenced Zone Tide (ERZT) separation model, ERS methods were used for reducing data to MLLW. After final tides were received, the final TCARI grids were applied to the data and used for reducing features to MLLW. The TCARI grid provided by HSD OPS was misaligned with the shoreline due to an error in georeferencing the grid. See Section B.5.4 for more information.2016-11-182016-11-289450460.tidFinal ApprovedO393FA2016_Verified.tcFinalERS via Poor Mans VDATUMERS methods were used as the final means of reducing H12973 to MLLW for submission. Data were initially reduced via traditional tidal means until an ERZT separation model could be calculated. This empirically derived model was then checked for consistency and compared to the Poor Man's VDatum (PMVD) separation model provided with the Project Instructions. The PMVD separation model was then vertically shifted such that the average difference between these two separation models is zero. This vertical shift de-biases the PMVD separation model, correcting for local offsets that cannot be effectively modeled by the PMVD. In areas where the PMVD model did not have sufficient coverage, such as near shore areas, the ERZT separation model was appended to the PMVD model creating the composite ERZT/PMVD separation model listed above and used to reduce H12973 to MLLW. For further information see the ERS Capability Memo, submitted under separate cover. O393FA2016_PMVD_EPSG6338_WGS84-MLLW_Composite.csarAdditional information discussing the vertical or horizontal control for this survey can be found in the accompanying Horizontal and Vertical Control Report (HVCR).World Geodetic System 1984 (WGS84)Differential correctors from the US Coast Guard beacon at Annette Island (323 kHz) were used in real-time for acquisition when not otherwise noted in the acquisition logs.Annette Island, AK - 323 kHz (100 BPS)UTM Zone 09 NorthSingle BaseANDY9677Vessel kinematic data were post-processed using Applanix POSPac processing software and Single Base Positioning methods described in the DAPR. Smoothed Best Estimate of Trajectory (SBET) and associated error (RMS) data were applied to all MBES data in CARIS HIPS and SIPS. For further details regarding the processing and quality control checks performed, see the H12973 POSPac Processing Logs spreadsheet located in the Separates folder. See also the OPR-O393-FA-16 Horizontal and Vertical Control Report (HVCR), submitted under separate cover.