OPR-Q191-KR-13Krenitzin Islands, AlaskaKrenitzin IslandsFugro Pelagos, Inc.H125497The Hydrographic Sheet should be accompanied by this form, filled in as completely as possible, when the sheet is forwarded to the Office.Northwest of Akutan IslandAlaskaUnited States400002013Dean MoylesNavigable Area2013-05-152013-06-282013-07-15Multibeam Echo SounderMultibeam Echo Sounder BackscattermetersUTMUTCPacific Hydrographic BranchThe 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 Geophysical Data Center (NGDC) and can be retrieved via http:// www.ngdc.noaa.gov/.ContractorH12549 is located Northwest of Akutan Island.54.30694165.9763954.08278166.22639Survey Limits were acquired in accordance with the requirements in the Project Instructions and the HSSD.The purpose of this work is to provide NOAA with modern and accurate hydrographic survey data for the area Northwest of Akutan Island. The survey covered 23.85 square nautical miles of critical survey area as designated in the NOAA Hydrographic Survey Priorities, 2012 edition. The entire survey is adequate to supersede previous data.Survey Coverage was in accordance with the requirements in the Project Instructions and the HSSD.H12549 Survey Limitsfile:///M:/OPRQ191KR13/Surveys/H12549/Compilation/Report/Components/H12549%20Survey%20Limits.pngOcean Pioneer0213.080000012.7200213.080000012.7205.970000023.852013-06-282013-06-292013-06-302013-07-012013-07-062013-07-112013-07-122013-07-15No processed data for 6/28/2013 was submitted.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.Ocean Pioneer20514 Applanix POS M/V v4 Positioning and Attitude System OceanScienceUCTDConductivity, Temperature and Depth SensorReson7125MBES ResonSVP70Sound Speed SystemWaterLOG H3611 (Radar Water Level Sensors) were installed on the port and starboard gunwales of M/V Ocean Pioneer to obtain a more precise static draft measurement. Samples were taken over a 10 minute period and averaged to determine the vessel’s draft. Traditional static draft measurement techniques were also employed as a substitute for the WaterLOG H3611 measurements when required.Crosslines were planned and well distributed throughout the survey to ensure adequate quality control. Total crossline length surveyed was 12.72 nautical miles or 5.97 percent of the total mainscheme line length. Each crossline was compared to the entire mainscheme line plan through a 4m CUBE surface using the CARIS HIPS QC report routine. Good conformity was seen between the mainscheme lines and the crosslines. 0.10.2Ocean Pioneer1.74000.250The majority of the data fell within IHO Order 1a accuracy specifications. Nodes that exceeded the allowable specifications were located in rough or rapidly changing topography or areas where the outer beams of the coverage boundaries were the single contributor to the surface. Despite the higher uncertainty values in these areas, agreement between adjacent lines and co-linearity between soundings was good. Note: The percentage of nodes within IHO Oder 1a, were computed by CARIS using the Surface QC Report utility and are as follows: CUBE Surface Uncertainty Report Surface, Depth Range (m), % of nodes within IHO Order 1a H12549-4m_Final 36 - 80 100.00% H12549-8m_Final 72 - 160 100.00% H12549-16m_Final 144 - 320 100.00% H12549-32m_Final 320 - 640 100.00% As illustrated in the uncertainty errors graphic, the uncertainty is generally lowest near the sonar nadir beams and increases toward the outside of each swath. This is expected and primarily a result of the sonar’s device model used within CARIS HIPS for TPU calculations. In general, total propagated uncertainty varies proportionally to water depth. Outer beams also have higher uncertainty values as a function of the bottom-detection algorithms within the sonar. Data met project specifications.H12549 Uncertaintyfile:///M:/OPRQ191KR13/Surveys/H12549/Compilation/Report/Components/Priority_7_H12549_Uncertainty.pngH12549 Uncertainty Errorsfile:///M:/OPRQ191KR13/Surveys/H12549/Compilation/Report/Components/Priority_7_H12549_Uncertainty_Errors_0-4m.pngThe surveys are in agreement along their common borders. The conformity between H12549 and the bordering survey area (H12548) was inspected during processing, using CARIS HIPS’ Subset Editor routine and finalized BASE Surfaces. Difference surfaces were also created at a 4-meter resolution between H12549, and the junction with survey area H11713 (2007), and also for the junction of H12549 and survey area W00225 (2011). The data were well within the IHO Order 1a allowable error.H11713100002007Fugro Pelagos, Inc.SA difference surface was created to compare the 4-meter surface from H12549 and the junction with the 5-meter surface from H11713 (2007), confirming that approximately 70.97% of the nodes agree to within +/-0.50m. The other 29.03% of the nodes were primarily affected by sound refraction errors in the outer beams of the sonar swath for the survey lines in the southern-most portion of H12549. The data were well within the IHO Order 1a allowable error.H12549 Junctions with H11713file:///M:/OPRQ191KR13/Surveys/H12549/Compilation/Report/Components/H11713_Junction_With_H12549.pngDifference Surface H12549 vs. H11713file:///M:/OPRQ191KR13/Surveys/H12549/Compilation/Report/Components/Diff_H12549-H11713_Overview_Annotated.pngDifference Surface Statistics H12549 vs. H11713file:///M:/OPRQ191KR13/Surveys/H12549/Compilation/Report/Components/Diff_Surf_Statistics_H12549-W11713_Ogive.pngW00225400002011Fugro Pelagos, Inc.WA difference surface was also created at a 4-meter resolution between H12549, and the junction with survey area W00225 (2011), confirming that approximately 91.83% of the nodes agree to within +/-0.50m. The other 8.17% of the nodes were on the outer edges of the swath at the coverage boundaries or were located in areas where the seafloor had a relatively steep slope. Furthermore, the largest differences between the two survey datasets were seen in areas with water depths greater than 100 meters. The data were well within the IHO Order 1a allowable error.H12549 Junctions with W00225file:///M:/OPRQ191KR13/Surveys/H12549/Compilation/Report/Components/W00225_Junction_With_H12549.pngDifference Surface H12549 vs. W00225file:///M:/OPRQ191KR13/Surveys/H12549/Compilation/Report/Components/Diff_H12549-W00225_Overview_Annotated.pngDifference Surface Statistics H12549 vs. W00225file:///M:/OPRQ191KR13/Surveys/H12549/Compilation/Report/Components/Diff_Surf_Statistics_H12549-W00225_Ogive.pngNo junction comparison was done with concurrent survey H12548. 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.Sound Speed Refraction ErrorsSound speed refraction errors were seen in the outer beams of the swaths of survey lines that were run in deeper water. However, line overlap was sufficient, and the affected soundings were rejected in CARIS HIPS’ Subset Editor routine to ensure the CUBE surface met IHO Order 1a specifications.Sound speed measurements were conducted and applied as discussed in the Corrections to Echo Soundings section of the DAPR.All equipment and survey methods were used as detailed in the DAPR.Data Density The NOS Hydrographic Surveys Specifications and Deliverables, April 2012, requires 95% of all nodes to be populated with at least five soundings. Survey H12549 met these project specifications. Density requirements for H12549 were achieved with at least 99.49% of finalized surface nodes containing five or more soundings. Nodes that failed to meet the allowable specifications were located in rough or rapidly changing topography or areas where the outer beams of the coverage boundaries were the single contributor to the surface. CUBE Surface Density Report Surface, Depth Range (m), % of nodes within HSSD 2012 H12545-4m_Final 36 - 80 99.80% H12545-8m_Final 72 - 160 99.86% H12545-16m_Final 144 - 320 99.50% H12545-32m_Final 320 - 640 99.66% Detection requirements were met by minimizing vessel speed when necessary, using sonar range scales appropriate to the water depth to maximize ping rates, and maximizing swath overlap. These variables were adjusted in real-time by the online acquisition crew based on the WinFrog QC and coverage displays. The shipboard processing crew provided feedback after preliminary processing and coverage creation in CARIS HIPS and In-fills were run as necessary.H12549 Data Densityfile:///M:/OPRQ191KR13/Surveys/H12549/Compilation/Report/Components/Priority_7_H12549_Data_Density.pngAll data reduction procedures conform to those detailed in the DAPR.All sounding systems were calibrated as detailed in the DAPR.Towed Side Scan Sonar (SSS) operations were not required by this contract, but the backscatter and beam imagery snippet data from all multibeam systems were logged and are stored in the s7k files. All beam imagery snippet data was logged in the 7028 record of the s7k file for the project.Version 5.3.2H12549_4mCUBE40361NOAA_4mComplete MBESH12549_4m_FinalCUBE43680NOAA_4mComplete MBESH12549_8mCUBE80361NOAA_8mComplete MBESH12549_8m_FinalCUBE872160NOAA_8mComplete MBESH12549_16mCUBE160361NOAA_16mComplete MBESH12549_16m_FinalCUBE16144320NOAA_16mComplete MBESH12549_32mCUBE320361NOAA_32mComplete MBESH12549_32m_FinalCUBE32320640NOAA_32mComplete MBESThe surfaces have been reviewed where noisy data, or 'fliers' are incorporated into the gridded solution causing the surface to be shoaler than the true seafloor. Where these spurious soundings cause the gridded surface to be shoaler than the reliably measured seabed by greater than the maximum allowable TVU at that depth, the noisy data have been rejected and the surface recomputed. The NOAA CUBE parameters mandated in HSSD were used for the creation of all CUBE BASE surfaces in Survey H12549.Additional information discussing the vertical and horizontal control for this survey can be found in the accompanying HVCR.Mean Lower Low WaterDiscrete ZoningUnalaska, Dutch Harbor9462620King Cove9459881Broad Bight9462676SE Tigalda Island9462705Green Bight94627869462676.tidVerified Observed9462705.tidVerified Observed9462786.tidVerified ObservedOPR-Q191-KR-13_Zoning_20131008.zfdPreliminary2013-10-242013-10-31On October 08, 2013, John Oswald and Associates (JOA) issued verified tidal data and zoning for OPR-Q191-KR-13. All sounding data was then re-merged using CARIS HIPS and SIPS tide routine. JOA verified tidal data were used for all final Navigation BASE surfaces and S-57 Feature files. It should be noted that the tidal data applied to OPR-Q191-KR-13 is JOA verified and not CO-OPs verified. JOA are currently in the WALI verification process, which is pending, awaiting CO-OPs approval. Since the timeframe for CO-OPs verification is unknown, FPI were given approval, by our COTR, to submit the data with the JOA verified tides and zoning applied.CO-OPs approved the JOA verified tidal data and zoning on January 30, 2014. NAD83UTMSingle BaseBroad BightBB_ESE Tigalda IslandTI_N For real-time DGPS corrections, a CSI MBX-3 unit was tuned to the Cold Bay, Alaska USCG DGPS site. The unit output differentially corrected positions at 1 Hz to the (POS MV) 320 V4 where it was integrated with inertial data, and a position for the top-center of the IMU generated. This position was logged concurrently with the bathymetry from WinFrog and the POS file using Fugro Pelagos PosMvLogger. It was later corrected for offsets to the multibeam echosounder (MBES) by CARIS HIPS in post-processing. Final positioning was done using post-processed kinematic (PPK) methods. Applanix POSPac MMS v5.4 software was used in conjunction with the POS files and local 1Hz base station data to generate a higher accuracy position, which was applied in processing to replace the real-time position records. Cold Bay DGPS Station1653118000072002-022013-10-012013-09-28The Raster chart was downloaded from NOAA’s Office of Coast Survey website on October 9, 2013. Given that the survey area was ensonified with 100% multibeam coverage, discrepancies were discovered between the charted and surveyed depths. Sounding agreement between surveyed soundings on sheet H12549 and spot soundings displayed on Raster chart 16531 varied between 1 and 2 fathoms. The Hydrographer recommends that soundings within the survey limits of H12549 supersede all prior survey and charted depths.Chart Comparison H12549 vs. 16531file:///M:/OPRQ191KR13/Surveys/H12549/Compilation/Report/Components/H12549_vs_16531.PNGUS3AK61M300000162011-01-122013-06-24falseThe ENCs were downloaded from NOAA’s Office of Coast Survey website on October 9, 2013. Thus, the issue dates displayed in the table above are more recent than the dates in the Project Instructions. Given that the survey area was ensonified with 100% multibeam coverage, discrepancies were discovered between the charted and surveyed depths. Sounding agreement between surveyed soundings on sheet H12549 and spot soundings displayed on ENC US3AK61M varied between 1 meter and 10 meters. Generally, the surveyed data in the vicinity of the charted spot soundings from the ENC agreed to within 1 to 5 meters. However, the largest discrepancy found was 18 meters. Although the ENC displays the spot soundings in meters, the contours are displayed in fathoms. The surveyed data for sheet H12549 shows contours that generally agree with the contour trends from ENC US3AK61M. The Hydrographer recommends that soundings within the survey limits of H12549 supersede all prior survey and charted depths.Chart Comparison H12549 vs. US3AK61Mfile:///M:/OPRQ191KR13/Surveys/H12549/Compilation/Report/Components/H12549_vs_US3AK61M.pngNo comparison with Chart 16520 (1:300,000) was done. However, the comparison to ENC US3AK61M is adequate.US4AK6FM8000082011-04-282013-05-02falseGiven that the survey area was ensonified with 100% multibeam coverage, discrepancies were discovered between the charted and surveyed depths. Sounding agreement between surveyed soundings on sheet H12549 and spot soundings displayed on ENC US4AK6FM varied between 1 meter and 5 meters. Although the ENC displays the spot soundings in meters, the contours are displayed in fathoms. The surveyed data for sheet H12549 shows contours that generally agree with the contour trends from ENC US4AK6FM. The Hydrographer recommends that soundings within the survey limits of H12549 supersede all prior survey and charted depths.Chart Comparison H12549 vs. US4AK6FMfile:///M:/OPRQ191KR13/Surveys/H12549/Compilation/Report/Components/H12549_vs_US4AK6FM.pngNo AWOIS items exist for this survey.Maritime Boundary Points were assigned for this survey, but were not addressed.No charted features exist for this survey.No uncharted features exist for this survey.No Danger to Navigation Reports were submitted for this survey.No shoals or potentially hazardous features 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.No bottom samples were required for this survey. However, two bottom characteristics were imported from the ENC to be retained.Shoreline was not assigned in the Hydrographic Survey Project Instructions or Statement of Work.Shoreline was assigned for all surveys in this project. H12549 is an offshore survey and no shoreline features were located within it's limits.No prior survey comparisons exist for this survey.Aids to navigation (ATONs) do not exist for this survey.Overhead features do not exist for this survey.Submarine features do not exist for this survey.No ferry routes or terminals exist for this survey.No platforms exist for this survey.No significant features exist for this survey.There is no present or planned construction or dredging within the survey limits.Final Feature FileAll features, including ones from the NOAA assigned feature file, that were within the geographical bounds of H12549 are included in the “H12549_Field_Features.000” file. Features that fell within the survey limits were addressed and attributed appropriately. This file contains the object and metadata with extended attributes as required in the Specifications and Deliverables (April 2012). Note: Since CARIS Notebook and Bathy DataBASE were unable to export to S-57 with the parameters outlined in section 8.2 of the HSSD 2012, an additional text file with the required meta information was sent to accompany the S-57 file. Shoreline investigation was not assigned for this survey. H12549 is an offshore survey and no shoreline features were located within it's limits.No new surveys or further investigations are recommended for this area.No new insets 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 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 and Specifications Deliverables Manual, 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 Report.Dean MoylesSenior Hydrographer (ACSM Cert. No. 226) 2013-11-04Data Acquisition and Processing Report2013-11-04Horizontal and Vertical Control Report2013-11-04Tides and Water Levels Package2013-11-04MAR-P-001-R2 MBES Acquisition Procedures2013-11-04DAC-P-010-R3 MBES Processing Procedures2013-11-04