OPR-P133-RA-12Chirikof Island and Vicinity, AKChirikof Island and Vicinity, AKNOAA Ship RAINIERH124494Hydrography shall consist of Navigable Area Surveys.South CapeAlaskaUnited States400002012CDR Richard T. Brennan, NOAANavigable Area2012-05-152012-06-192012-08-07Multibeam Echo SounderMultibeam Echo Sounder BackscattermetersMean Lower Low WatermetersMean Lower Low WaterUniversal Transverse Mercator (UTM)UTCPacific 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. Revisions and Rednotes were generated during office processing. The processing branch concurs with all information and recommendations in the DR unless otherwise noted. Page numbering may be interrupted or non-sequential. All pertinent records for this survey, including the Descriptive Report, are archived at the National Geophysical Data Center (NGDC) and can be retrieved via http://www.ngdc.noaa.gov/.This hydrographic survey was completed as specified by hydrographic survey Project Instructions OPR-P133-RA-12 signed May 15, 2012 and all other applicable direction. The survey area is the South Cape vicinity of Chirikof Island, Alaska. This survey corresponds to sheet "4" in the sheet layout provided with the Project Instructions (Figure 1).55.8508155.46172777855.7304222222155.6766251H12449 Area Surveyed (chart 16587).SupportFiles\H12449_Coverage.jpgThis project is being conducted in support of NOAA's Office of Coast Survey to provide contemporary hydrographic data in order to update the nautical charting products and reduce the survey backlog within the area. The need for nautical chart updates is due to an increasing number of passenger vessels, tour vessels and large fishing fleets in the area. In addition, the data would be used to create DTM maps in support of efficiencies in longline and pot fisheries, while minimizing habitat disruption. The entire survey is adequate to supersede previous data.Survey H12449 met HSSD complete multibeam coverage specifications, including the five soundings per node density requirements (Figures 2-3). 99.6 percent of H12449 nodes are populated with greater than 5 soundings.2H12449 Sounding density.SupportFiles\H12449_Density.jpg3H12449 Sounding density summary tableSupportFiles\H12449_Density_Stats.jpgComplete multibeam echosounder (MBES) coverage was achieved in the assigned survey area as per the Project Instructions except in areas foul with kelp. These foul areas were generally located very near-shore, subject to dangerous wave action and judged to be navigationally insignificant. All areas shown in Figure 4 where H12449 coverage did not extend to the sheet limits, were foul with kelp.4H12449 Survey Outline.SupportFiles\H12449_Survey_Outline.jpg5H12449 Coverage.SupportFiles\H12449_Coverage_2.jpgKelp holidays: Complete multibeam coverage was not possible in areas with extensive kelp beds. Figure 6 shows examples of such holidays in the vicinity of 55-49-20.65N, 155-32-47.71W. Other examples of kelp holidays are located at 55-48-08.16N, 155-32-45.76W and 55-49-28.82N, 155-32-56.43W. Acoustic Shadow holidays: Numerous insignificant holidays were the result of acoustic shadowing; the example shown (Figures 7-8) is located at 55-46-45.18N, 155-33-24.63W. These holidays occurred in rocky seabed areas where data density on the 'dark' side of a feature, or between features, was too sparse to produce a surface at the appropriate resolution. 6Example of holidays due to kelp.SupportFiles\H12449_Coverage_Holiday.jpg7Example of holiday due to acoustic shadow, subset view.SupportFiles\H12449_Downslope_Shadow.jpg8Example of acoustic shadow area.SupportFiles\H12449_Downslope_Shadow_planview.jpgData is adequate for charting.2012-06-192012-07-172012-07-192012-07-202012-07-212012-07-232012-07-312012-08-032012-08-0730024.650509.330000028.3405.5Shoreline was investigated in accordance with the Project Instructions and the HSSD.Bottom Samples were acquired in accordance with the Project Instructions or the HSSD.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.2801 (RA-4)283.52802 (RA-5)283.52803 (RA-3)283.52804 (RA-6)283.5ResonSeaBat 7125 SVMBESApplanixPOS M/VVessel Attitude SystemSBESEACAT 19 ProfilerSound Speed SystemSBESEACAT 19plus ProfilerSound Speed SystemResonSVP 70Sound Speed SystemH12449 Multibeam echosounder crosslines totaled 28.34 nautical miles, comprising 5.5% of mainscheme MBES bathymetry (Figure 9). Separate 1-meter CARIS BASE surfaces of the MS and XL data were created, from which a surface difference layer was generated In CARIS HIPS and SIPS (Figure 10). Statistics were then derived from the difference surface and are shown below (Figure 11). The mean difference between depths derived from the mainscheme and crosslines is -0.01 meters; the standard deviation is 0.19 meters.9H12449 Mainscheme and Crosslines.SupportFiles\H12449_XL_MS.jpg10H12449 1-meter resolution difference layer.SupportFiles\H12449_XL_Diff_Surface2.jpg11H12449 1-meter resolution difference surface histogram.SupportFiles\H12449_XL_Comparison.jpg00.14280130.15280230.15280330.15280430.15Uncertainty values of submitted, finalized grids were calculated in CARIS using the "Greater of the Two" of total propagated uncertainty and standard deviation (scaled to 95%). In CARIS HIPS, an "IHOness" attribute layer was created for the 1, 2 and 4-meter resolution surfaces, based on the difference between calculated uncertainty of the nodes and the allowable IHO uncertainty (Figure 12). To quantify the extent to which accuracy requirements were met, the IHOness layer was queried within CARIS and then exported to Excel to produce the table shown in Figure 13.12H12449 IHO Order 1 compliance.SupportFiles\H12449_IHOness_Layer_A.jpg13H12449 IHO compliance statistics.SupportFiles\H12449_IHO_Stats.jpgH12449 junctions with five concurrent MBES surveys from the same project (OPR-P133-RA-12) and two Fugro LADS lidar surveys from 2006 (Figures 13-14). Junction comparisons were performed by creating a CARIS difference surface for the area of overlap then color-coding by depth for analysis. Additional comparisons were made using CARIS subset editor to examine MBES sounding data, or the lidar reference surface, for consistency and agreement. H11543100002006Fugro LADSNA broad area of overlap exists between H12449 and H11543, extending several hundred meters both north to south and east to west (Figure. 15). A CARIS difference layer was created using the H12449 2-meter resolution BASE surface and the H11543_LI_BASE_3m.csar file provided with the Project Instructions. Statistics from the H12449 / H11543 difference surface were computed in CARIS and exported to the excel table shown in Figure 17. The mean difference between the surveys is 0.16 meters; the standard deviation is 0.36 meters; H12449 was the shoaler of the two surveys. The largest depth differences coincide with areas of greatest seafloor relief. This correlation between depth discrepancies and bottom relief may be a function of the gridding algorithms used.13H12449 MBES Junction survey overview.SupportFiles\H12449_SWMB_Junctions.jpg14H12449 2006 Lidar junction survey overview.SupportFiles\H12449_LIDAR_Junctions.jpg15H12449 / H11543 Junction.SupportFiles\H12449_H11543_Comparison.jpg16H12449 / H11543 Subset view.SupportFiles\H12449_H11543_Subset.jpg17H12449 / H11543 Difference surface results.SupportFiles\H12449_H11543_Difference_Surface_Stats.jpgH11544100002006Fugro LADSWH12449 junctions with lidar survey H11544 to the west as shown in Figure 18; the most extensive area of overlap is to the north of the common area. A CARIS difference layer was created using the H12449 2-meter resolution BASE surface and the H11544_LI_BASE_3m.csar file provided with the Project Instructions. Statistics from the H12449 / H11544 difference surface were computed in CARIS and exported to the excel table shown in Figure 20. The mean difference between the surveys is -0.09 meters; the standard deviation is 0.6 meters in approximately 20 meters water depth; H12449 was the shoaler of the two surveys. The largest depth differences coincide with areas of greatest seafloor relief. This correlation between depth discrepancies and bottom relief may be a function of the gridding algorithms used. 18H12449 / H11544 Difference surface (section).SupportFiles\H12449_H11544_Comparison.jpg19H12449 / H1544 Subset view.SupportFiles\H12449_H11544_Subset.jpg20H12449 / H11544 Difference surface results.SupportFiles\H12449_H11544_Difference_Surface_Stats.jpgH12448400002012NOAA Ship RAINIERSThe junction with survey H12448 was approximately 175 meters wide along the south and west limits of H12449 (Figure 21). A CARIS difference layer was created using the 4-meter resolution surface from both sheets. Statistics from the H12449 / H12448 difference surface were computed in CARIS and exported to the excel table shown in Figure 23. The mean difference between the surveys is -0.22 meters; the standard deviation is 0.17 meters in approximately 50 meters water depth; H12449 was the shoaler of the two surveys.21H12449 / H12448 Difference surface.SupportFiles\H12449_H12448_Comparison.jpg22H12449 / H12448 Subset view.SupportFiles\H12449_H12448_Subset.jpg23H12449 / H12448 Difference surface results.SupportFiles\H12449_H12448_Difference_Surface_Stats.jpgH12446250002012NOAA Ship RAINIERWThe junction with survey H12446 was approximately 130 meters wide along the western limits of H12449 (Figure 24). A CARIS difference layer was created using the 2-meter resolution surface from both sheets. Statistics from the H12449 / H12446 difference surface were computed in CARIS and exported to the excel table shown in Figure 26. The mean difference between the surveys is 0.03 meters; the standard deviation is 0.26 meters in approximately 15-20 meters water depth; H12449 was the deeper of the two surveys. 24H12449 / H12446 Difference surface.SupportFiles\H12449_H12446_Comparison.jpg25H12449 / H12446 Subset view.SupportFiles\H12449_H12446_Subset.jpg26H12449 / H12446 Difference surface results.SupportFiles\H12449_H12446_Difference_Surface_Stats.jpgH12455400002012NOAA Ship RAINIEREThe junction with survey H12455 was approximately 220 meters wide along the eastern sheet limits of H12449 (Figure 27). A CARIS difference layer was created using the 2-meter resolution surface from both sheets. Statistics from the H12449 / H12455 difference surface were computed in CARIS and exported to the excel table shown in Figure 29. The mean difference between the surveys is 0.11 meters; the standard deviation is 0.19 meters in approximately 30-55 meters water depth; H12449 was the shoaler of the two surveys. 27H12449 / H12455 Difference surface.SupportFiles\H12449_H12455_Comparison.jpg28H12449 / H12455 Subset view.SupportFiles\H12449_H12455_Subset.jpg29H12449 / H12455 Difference surface results.SupportFiles\H12449_H12455_Difference_Surface_Stats.jpgH12450400002012NOAA Ship RAINIERNThe junction with survey H12450 was approximately 100 meters wide along the northern sheet limits of H12449 (Figure 30). A CARIS difference layer was created using the 2-meter resolution surface from both sheets. Statistics from the H12449 / H12450 difference surface were computed in CARIS and exported to the excel table shown in Figure 32. The mean difference between the surveys is -0.04 meters; the standard deviation is 0.1 meters in approximately 12-25 meters water depth; H12449 was the shoaler of the two surveys. 30H12449 / H12450 Difference Surface.SupportFiles\H12449_H12450_Difference_Surface.jpg31H12449 / H12450 Subset view.SupportFiles\H12449_H12450_Subset.jpg32H12449 / H12450 Difference surface results.SupportFiles\H12449_H12450_Difference_Surface_Stats.jpgH12454400002012NOAA Ship RAINIERNEH12449 does not junction with H12454 in a significant enough manner to warrant a full comparison.Sonar system quality control checks were conducted as detailed in the quality control section of the DAPR.Time Synchronization LossAn intermittent Reson time synchronization loss resulted in degradation of some bathymetric data (Figures 33-34). This condition occurred at infrequent, short duration episodes, lasting a matter of a few seconds on the following boat / day / lines: 2803/DN199/1916, 2803/DN199/1927, 2804/DN171/1722, 2804/DN171/1940. The affected data was deleted or rejected in CARIS, then reacquired.33Reson Time sync error message.SupportFiles\H12449_Time_Sync.jpg34Surface artifact due to time sync error before correction.SupportFiles\H12449_Time_Sync_Error.jpgApplication of SBET DataSmoothed Best Estimate Trajectory (SBET) and Root Mean Square (RMS) data were applied to all H12449 survey lines with the following exceptions: Vessel 2802, DN199, high frequency (HF) line 1750 did not load PPK data. The associated true heave file was removed from this line as noted and explained in the acquisition log. Vessel 2802, DN203 HF lines did not load PPK data due to SBET time extents not overlapping with lines. Vessel 2804, DN216 HF lines did not load PPK data due to fatal error processing SBET file. Data is adequate for charting.Suboptimal Sound Velocity CorrectionDue to variations in the water column, thermal layering, tidal influence and other related factors, a distinct demarcation of water masses was sometimes observed in the field. This proved problematic in the acquisition and application of sound velocity (SV) correction data. Despite the best efforts of the hydrographers to conduct sufficient SV casts distributed both spatially and temporally, in some areas sound velocity data correction was suboptimal. Some data exhibit upward or downward deflection ("smiles" or "frowns") when viewed in CARIS 2D subset editor, indicative of inaccurate SV correction. To compensate, some outer-beam soundings obviously in error were flagged as rejected. An example of suboptimal SV data correction at position 55-47-35.55N, 155-29-27.01W is shown below (Figure 35).35Example of suboptimal SV correction.SupportFiles\H12449_SV_Smiles.jpgData is adequate for charting.Vertical Offset A vertical offset of approximately 0.15 meters was observed (at position 55-48-38.86N, 155-28-40.18W) where data acquired on different days overlapped (Figure 36). Factors which may have contributed to this offset include poor SV correction, inaccurate dynamic draft or tide modeling. In order to determine whether this offset was due to a less than accurate tidal zoning model, the affected multibeam data was referenced to the ellipse by applying GPS tides in CARIS. Once referenced to the ellipse, the vertical offset between overlapping lines was almost totally eliminated (Figure 37). It should be noted that H12449 multibeam data with zoned tides applied were delivered to the processing branch and are within the allowable uncertainty margins outlined in NOAA 2012 HSSD.36Vertical offset between days - Zoned tides applied.SupportFiles\H12449_Different_DN_Offset.jpg37Vertical offset eliminated - GPS tides applied.SupportFiles\H12449_GPS_Tides_Applied.jpgData is adequate for charting.Sound speed profiles were acquired using SBE-19 and SBE-19 plus CTD probes at discrete locations within the survey area at four hour intervals or more frequently when observed surface sound speed values changed significantly, (approximately 3-meters per second), or when surveying in a new area. A single sheet-wide concatenated SVP was created and applied to all H12449 survey lines using the "Nearest in distance within (4 hours) Time" profile selection method. A total of thirty nine SVP casts were taken and applied (Figure 38).38H12449 Sound velocity cast locations.SupportFiles\H12449_SV_Casts.jpgAll Equipment and survey methods were used as detailed in the DAPR.All data reduction procedures conform to those detailed in the DAPR.All sounding systems were calibrated as detailed in the DAPR.Backscatter data was logged as .7k files and submitted directly to NGDC, and is not included with the data submitted to the Branch.NOAA ProfileSoftware programs and versions used for data processing are described in the DAPR.The Feature Object Catalog used for this survey was NOAA Extended Attributes Files V5_2.H12449_1mCUBE12.5357.12NOAA_1mComplete MBESH12449_2mCUBE22.6857.12NOAA_2mComplete MBESH12449_4mCUBE42.8457.10NOAA_4mComplete MBESH12449_1m_FinalCUBE12.4520NOAA_1mComplete MBESH12449_2m_FinalCUBE21840NOAA_2mComplete MBESH12449_4m_FinalCUBE43657NOAA_4mComplete MBESH12449_CombinedCUBE42.4557.10N/AComplete MBESOne field sheet, three single-resolution, three finalized and one combined CARIS BASE surfaces were created to process this survey. Final BASE surface resolution and depth ranges were specified in the file "CUBEParams_NOAA.xml" submitted with this report. A H12449 Critical Soundings layer includes four examined and one designated sounding. The designated sounding was to created ensure the surface honored the least depth of a significant rock; the examined soundings were flagged by the hydrographer during data analysis and may be ignored by the reviewer.H12449_Office_4m_Combined.csar created during office processing was used for compilation.Additional information discussing the vertical or horizontal control for this survey can be found in the submitted HVCR.Mean Lower Low WaterDiscrete ZoningSand Point94594509459450.tidFinal ApprovedP133RA2012CORP.zdfFinal2012-08-092012-08-10Applied water levels were based on data collected at Sand Point, AK (9459450), and preliminary zoning was used as provided by CO-OPS. Preliminary tide zones were accepted as final; final tides were applied to all data.Tide note appended.North American Datum of 1983 (NAD83)Single BaseChirikof Island, AKN/AIn conjunction with this project a GPS base station was established by Rainier personnel in the vicinity of Slaughterhouse Lake near the northeast end of Chirikof Island. Vessel kinematic data (POS files) were post-processed with Applanix POSPac and POSGNSS software using Single Base processing methods described in the DAPR. SBET and associated error (RMS) data was applied to all survey lines with the exception of those described in section B.2.5.1 of this report.Vessel 2804 acquired shoreline buffer data on DN171 prior to base station installation. Precise Point Position (PPP) correction was applied to this data only.Kodiak (313 kHz)Cold Bay (289 kHz)Kenai (310 kHz)DGPS signal reception was variable during this survey. The USCG DGPS stations at Kodiak (313 kHz), Cold Bay (289 kHz) and Kenai (310 kHz) Alaska were used for initial horizontal control depending on which provided the best signal reception at the time of acquisition. Refer to H12449 processing and acquisition logs for details. Improved horizontal control was achieved through the use of Post Processed Kinematic data. 16587254113500022012-022012-09-042012-09-01A comparison was made between survey H12449 and chart 16587 using Caris BASE surfaces and sounding layer. H12449 soundings agreed with charted (16587) depths to within 1-fathom except as indicated in Figure 39. Charted depths circled in green indicate where H12449 soundings are within 1-fathom of charted depths. A single blue circled depth indicates where H12449 soundings are more than 1-fathom deeper than charted. The hydrographer recommends that a sounding set derived from survey H12449 be applied to chart 16587. A charted 10-fathom depth contour is positioned as much as 2 nautical miles too far offshore of the correct position determined by H12449 data. The actual 10-fathom contour is located at the junction between the green and blue depth ranges shown in Figure 40. A charted offshore 5-fathom depth contour is not supported by H12449 data and should be deleted (Figure 41). A new contour set should be derived from H12449 digital data. Refer to section D.2 of this report for information regarding shoreline feature investigation. 39H12449 Depth comparison.SupportFiles\H12449_Chart_Comparison_Depths.jpg40H12449 Contour recommendation.SupportFiles\DepthRanges.jpg41Incorrect 5-fathom contour.SupportFiles\FiveFathomContour.jpgUS3AK5KM350000142011-07-202012-07-05falseAn ENC land area at position 55-49-03.05N, 155-33-00.29W conflicts with chart 16587 which depicts a rock awash at the level of chart datum (Figure 42). H12449 observed no land area at the position indicated by the ENC. The discrepancy is likely due to the differences in scale between the ENC and chart 16587.42ENC / Chart confliction.SupportFiles\ENC_Comparison.jpgThe largest scale ENC in the survey area is US4AK5XM at 1:135,000 which corresponds to chart 16587. Concur with chart comparison. Area should be charted per the chart update product.No AWOIS items exist for this survey.No charted features with the label PA, ED, PD or Rep, exist for this survey.No uncharted features exist for this survey. Chart as per H12449 digital data.No Danger to Navigation Reports were submitted for this survey. Chart as per H12449 digital data.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.Limited shoreline verification was accomplished using the Project Reference File (PRF) and Composite Source File (CSF) provided with the Project Instructions. The PRF contains the limits of the assigned survey area, junction survey outlines, proposed bottom sample locations and a selection of features assigned for investigation. The CSF contains additional features for investigation as well as other features derived from multiple sources including NOAA charts, lidar surveys, and photogrammetry. From these two project-wide files, the hydrographer created an Assigned Feature File (AFF) which is a subset of those features specifically assigned for investigation by this survey. Both PRF and CSF are S-57 attributed datasets in .000 file format. Limited shoreline verification was conducted near predicted low water in accordance with the applicable sections of NOAA HSSD and FPM. All assigned features safe to approach, were addressed as required with S-57 attribution and recorded in the H12449_Final_Feature_File to best represent the features at chart scale. This file also includes any new features found in the field as well as recommendations to delete features disproved during the survey. Also submitted with this survey is a copy of the original H12449 AFF before any edits were made.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.An interested seafloor feature was located at position 55-46-23.99N, 155-29-05.98W. The feature resembles a staircase when seen in plan view (Figures 43-44).43H12449 Interesting feature - plan view.SupportFiles\H12449_Interesting_feature_Surface.jpg44H12449 Interesting feature - 3-D view.SupportFiles\H12449_Interesting_feature.jpgThere is no present or planned construction or dredging within the survey 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.CDR Richard T. Brennan, NOAACommanding Officer, NOAA Ship Rainier2012-10-11 LT Michael O. Gonsalves, NOAAField Operations Officer, NOAA Ship Rainier2012-10-11James B. JacobsonChief Survey Technician, NOAA Ship Rainier2012-10-11B. JacksonSenior Survey Technician, NOAA Ship Rainier2012-10-11Appendicies\IV - Tides And Water Levels\H12449.pdfSupportFiles\H12449_2801_Acquisition_Log.xlsmSupportFiles\H12449_2802_Acquisition_Log.xlsmSupportFiles\H12449_2803_Acquisition_Log.xlsmSupportFiles\H12449_2804_Acquisition_Log.xlsmSupportFiles\H12449_Shoreline_Sheets.pdfSupportFiles\H12449_SV_All_Boats.svpSupportFiles\Final_OPR-P133-RA-12_Chirikof_Island_and_Vicinity_AK_Instructions.pdf