OPR-P133-RA-12Chirikof Island and Vicinity, AKChirikof Island and Vicinity, AKNOAA Ship RAINIERH124527trueOffshore NW Chirikof IslandAlaskaUnited States400002012Richard T. Brennan, CDR/NOAANavigable Area2012-05-152012-06-242012-08-22Multibeam Echo SounderMultibeam Echo Sounder BackscattermetersMean Lower Low WaterfathomsMean Lower Low WaterUniversal Transverse Mercator (UTM)UTCPacific Hydrographic BranchThe project area is referred to as Sheet 7: “Chirikof Island and Vicinity, AK” within the Project Instructions. The area covers a 6 by 13 NM area northwest of Chirikof Island (Figure 1). The southeastern corner of the sheet is approximately 2 NM northwest of Nagai Rocks. It is located roughly between the three nautical mile line and the Territorial Sea boundary.55.979433155.69508155.874223156.0909891H12452 survey limits.file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/Figure_A_1_SurveyLimits.pngThis 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 may be used to create DTM maps in support of the efficiencies in longline and pot fisheries, while minimizing habitat disruption.The entire survey is adequate to supersede previous data.Data acquired on survey H12452 met complete multibeam coverage requirements, including the 5 soundings per node data density requirement outlined in section 5.2.2.2 of the HSSDM (Figure 2). In order to extract some descriptive statistics of the data density achievements, the density layer of each finalized surface was queried within CARIS and statistics were compiled in MS Excel. Density failures occurred at the edges of sheet acquisition and between a few lines in the outerbeams in the center of the survey (Figure 3). A data density threshold of five soundings or greater per node was statistically achieved in 100.0% of the nodes (Figure 4). 2H12452 data density. Areas in green meet the threshold of 5 soundings per node; red areas have a data density less than 5 soundings per node. file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/Figure_A_3_density.png3Examples of data density failures between lines. Areas in green meet the threshold of 5 soundings per node; red areas have a data density less than 5 soundings per node. file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/Figure_A_3_density_example.png4Summary table showing the percentage of nodes satisfying the 5 sounding per node density requirements, sub-divided by the appropriate depth ranges. Note the final row has a unit of square meters, and sums the number of different resolution nodes into a common unit of area. file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/Figure_A_3_density_stats.pngSurvey limits were acquired in accordance with the requirements in the Project Instructions and the Hydrographic Survey Specifications and Deliverables Manual (HSSDM).5H12452 survey coverage over Chart 16587file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/Figure_A_4_SurveyCoverage.pngComplete MBES coverage was achieved within the limits of hydrography specified in the Project Instructions and the HSSDM.2012-06-242012-07-122012-07-132012-07-222012-08-052012-08-062012-08-092012-08-112012-08-2260077.2S2210518.60000035.602804034.90000011.900553.50000047.500.08The only assigned features for this survey were bottom samples, which are addressed in A.7 of this report.There were eleven assigned bottom samples for survey H12452. However, bottom sample acquisition was modified to a total of 6 samples for survey H12452 (Figure 6). Three of the sample sites proposed in the Project Reference File were not acquired due to bottom depths in excess of 100 meters, due to depth limitations of sampling equipment. Due to time constraints and foul weather, a sample in the southeast region was not taken. An additional bottom sample site proposed in the Project Reference File was also not acquired and instead one sample was taken between two of the assigned locations. All other bottom samples were acquired in accordance with the Project Instructions and the HSSDM and are located in the Final Feature File.6H12452 bottom sample locations.file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/A7_BS_update.jpgRefer 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.S22123116.52804283.5Data was acquired by NOAA Ship RAINIER (S221) and NOAA Ship RAINIER Launch 2804 (RA-6). Both vessels acquired shallow water multibeam (MBES) soundings and sound velocity profiles. Launch 2804 collected bottom samples.KongsbergEM710MBESApplanixPOS-MV V4Vessel Attitude SystemRolls Royce Odim Brooke Ocean TechnologyMVP 200Sound Speed SystemReson7125MBESResonSVP 70Sound Speed SystemResonSVP 71Sound Speed SystemSeabirdSBE 19Conductivity, Temperature and Depth SensorMultibeam crosslines acquired by 2804 (RA-6) and S221 were compared to the mainscheme data acquired by S221 and 2804 (RA-6). The crosslines covered 47.5 nautical miles, comprising 8.5% of the 553 nautical miles of mainscheme lines. Separate 4-meter resolution CUBE surfaces were created for the mainscheme and crossline data. A difference surface was created, subtracting the crossline surface from the mainscheme surface (Figure 7). Statistics were derived from the difference surface and are shown in Figure 8. The mainscheme and crossline difference averaged -0.02 meters (mainscheme being shoaler), with a standard deviation of 0.42 meters. H12452 survey depth range is 44 to 166 meters. Areas of largest deflection are most likely due to sound velocity refraction (Figure 9).7H12452 crossline comparison showing the difference in meters between the mainscheme and crossline soundings for the 4 meter surface.file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/Figure_B_2.1XLN_map_4m.png8Histogram of 4-meter resolution difference surface between mainscheme and crosslines. The average difference was -0.02 meters and the standard deviation was 0.42 meters.file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/H12452_XLGraph.png9Crosslines in subset editor depicting separation between DN235 S221 lines 0005 and 0006 and DN222 2804 line 1905. This subset location was an exceptionally bad area. Sound velocity artifacts and outerbeam noise are discussed in Section B.2.6. file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/Figure_B_2.1_XLN_SE.png00.14280430.15S22110.05Uncertainty values of submitted, finalized grids were calculated in CARIS using the "Greater of the Two" between uncertainty and standard deviation (scaled to 95%). To visualize the locations in which accuracy requirements were met, for each finalized surface, a custom "IHOness" layer was created, based on the difference between calculated uncertainty of the nodes and the allowable IHO uncertainty (Figure 10). To quantify the extents to which accuracy requirements were met, the preceding "IHOness" layers were queried within CARIS and then exported to Excel (Figure 11). Overall, all data passed for IHO Order 2 and 99.9% of survey H12452 met the accuracy requirements for Order 1 as stated in the HSSDM. Sound velocity artifacts and outerbeam noise may indicate why IHOness failed in some areas.10H12452 met IHO accuracy standards for 99.9% of the data. Green passed the IHO threshold, yellow failed the threshold by less than 0.1 meters, and red failed the threshold by greater than 0.1 meters.file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/Figure_10_IHOness.png11Summary table showing the percentage of nodes satisfying the indicated IHO accuracy level, sub-divided by the appropriate depth ranges. 99.9% of the data passed IHO accuracy requirements. file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/Figure_B_2_Uncertainty_table_2.pngJunction comparisons were completed for surveys H12447, H12453, H12451, and H11687 (FAIRWEATHER, 2006), Figure 12. Surveys H12447, H12453, and H12451 were acquired concurrently with H12452. Depth comparisons were performed using CARIS difference surfaces compiled at the finest resolution for the depth range. Statistics were computed in CARIS, then exported to MS Excel for analysis. For the surveys acquired this year, multibeam was examined in CARIS Subset Editor for consistency and agreement. H116871350002006NOAA Ship FAIRWEATHERWA 16-meter surface of data acquired during survey H12452 was compared with a 16-meter surface of FAIRWEATHER survey H11687. Overlap between survey H12452 and H11687 averaged 245 meters along the western border of H12452 (Figure 13). The average difference in depth is -0.72 meters (H11687 being deeper), with a standard deviation of 0.49 meters (Figure 14). Depths for the junction range from 140 to 160 meters. The Descriptive Report for FAIRWEATHER survey H11687 indicates that sound velocity casts were taken every 15 minutes. However, velocity errors were still seen in the data. Due to the errors seen in the outerbeams of the data, filters were run on both the port and starboard beams and the remaining errors were manually cleaned in CARIS HIPS, as described in the Descriptive Report. It seems likely that remaining outerbeam noise and sound velocity problems in FAIRWEATHER survey H11687, combined with sound velocity issues in the outerbeams of survey H12452 has led to a discrepancy in the overlap between the two surfaces. 12H12452 junctions overview.file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/Figure_B_2_3JntOrview.png1316-meter difference surface of the junction of survey H12452 and H11687.file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/Figure_B_2_3H11687DiffOverview.png14Difference surface statistics between junction of H12452 and H11687. Depths average a difference of -0.72 meters with a standard deviation of 0.49 meters.file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/Figure_B_2_1H11687Jntn.pngH12447400002012NOAA Ship RAINIERSEOverlap with survey H12447 ranged from 155 to 260 meters for a 3 kilometer stretch along the SE portion of survey H12452 (Figure 15). A difference surface analysis between CUBE depth surfaces for each survey showed H12452 to be on average 0.01 meters shoaler, with a standard deviation of 0.14 meters (Figure 16). This is well within allowable IHO Order 1 accuracy at these depths.154-meter difference surface of the junction of survey H12452 and H12447.file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/Figure_B_2_3H12447DiffOverview.png16Difference surface statistics between junction H12452 and H12447. Average depth differences were -0.01 meters (H12452 being shoaler) with a standard deviation of 0.14 meters.file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/Figure_B_2_3H12447Histogram.pngH12453400002012NOAA Ship RAINIERSOverlap with survey H12453 averaged 400 meters across, along the SW border of survey H12452 (Figure 17). Depths for the junction range from 65 to 165 meters. A difference surface analysis between CUBE depth surfaces for each survey showed average depths between the two surveys to be the same (0.00 meters), with a standard deviation of 0.78 meters (Figure 18). This is well within allowable IHO Order 1 accuracy at these depths.174-meter difference surface of the junction of survey H12452 and H12453 in meters.file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/Figure_B_2_3H12453DiffOverview.png18Difference surface statistics between junction H12452 and H12453. Depths average a difference of 0.0 meters with a standard deviation of 0.78 meters.file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/Figure_B_2_3H12453Histogram.pngH12451400002012NOAA Ship RAINIEREOverlap with survey H12451 ranged from 160 to 260 meters along the eastern boundary of survey H12452 (Figure 19). A difference surface analysis between CUBE depth surfaces for each survey showed H12452 to be on average 0.01 meters shoaler, with a standard deviation of 0.66 meters (Figure 20). This is well within allowable IHO Order 1 accuracy at these depths.194-meter difference surface of the junction of survey H12452 and H12451 in meters.file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/Figure_B_2_3H12451DiffOverview.png20Difference surface statistics between junction H12452 and H12451. Depths average a difference of 0.01 meters with a standard deviation of 0.66 meters. file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/Figure_B_2_3H12451Histogram.pngSonar system quality control checks were conducted as detailed in the quality control section of the DAPR.Kongsberg EM710 Data ArtifactAt the time of this writing, there is a suspected integration problem within RAINIER's workflow between acquired EM710 multibeam data (integrated with an Applanix POS M/V), and later processing said data within CARIS HIPS. The result is an apparent oscillation of the outerbeams, which in some cases exceeded ±0.50 meters in magnitude (Figure 21). For a further discussion, refer to Section B.3.1.1 - Processing EM710 data with CARIS SVC Module.21A single line of EM710 data [DN219 - Line 0022]. When viewed acrosstrack the data appears to be experiencing outerbeam scattering (top); however, when viewed alongtrack, an oscillation associated with the Rainier EM710 artifact is seen (bottom). file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/Figure_B_2_5_1_Outerbeam_wiggles.pngSound Speed Profile FailureEleven of the 232 sound speed casts acquired by the ship were not applied to the ship's data because of an inaccurate salinity profile. In these erroneous casts, the MVP200 did not acquire the correct salinity, skewing the sound speed profile (Figure 22). These inaccurate casts caused sound velocity artifacts within the data as seen in Figures 23 and 24. These casts were identified and removed from the final concatenated SVP file and not applied to the survey. It is worth noting, a few weeks after acquisition concluded on survey H12452, the sound speed sensor within the MVP200 physically failed and was taken out of service.22A representative incorrect salinity profile, likely caused by a failing sensor. The associated sound speed cast was removed from survey H12452. file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/Figure_B_2.6_1_badSV.png23Prior to cast removal, data artifact caused by inaccurate SV profile.file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/Figure_B_2.6_1_badSV_sample.png24Inaccurate SV profile removed and new profile applied.file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/Figure_B_2.6_1_badSV_repair_sampleb.pngSound Speed Data ArtifiactsDue to the dynamic nature of the sound speed within the survey area, there are associated data artifacts seen within the data. These artifacts are most pronounced in the outer beams, and generally present themselves in the form of a “frown” (Figure 25). In areas where the CUBE surface was negatively impacted by the outer beams, the data was flagged as rejected to bring the surface back to the "true" seafloor. In some areas, outer beams were deflected by up to 0.30 meters; however, it is in the opinion of the Hydrographer that the data meets the requirements set forth in the HSSDM and should supersede charted data. 25Sample sound speed artifact seen in data acquired with the EM710 on DN195.file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/Figure_B_2_6_1_SVrefraction.pngModified EM710 Waterline ValueA routine part of acquisition with the EM710 is a measurement of the ship's waterline immediately before commencing operations, or immediately after any evolution that is suspected to impact said waterline (e.g. the deployment/recovery of launches); see 2012 RA DAPR. On DN218, however, a waterline measurement was taken that was suspected to be in error (-0.077 meters). Though the day was particularly calm, the measurement was not in keeping with historic values and led to a vertical shift in the data acquired by the ship on this day. To address this, an average (-0.228 meters) of the waterline value taken on this day and a prior day under similar loading conditions was used for DN218 on survey H12452. On several other days (DN176, DN204, DN224), the waterline value was not properly archived, so, based on the loading conditions and historic values, estimated waterline values were used (-0.155m, -0.200m, -0.170m). These changes were observed to improve vertical agreement in the data for survey H12452 and were properly archived for input into the HIPS vessel file.During ship acquisition, the RAINIER conducted casts approximately every 15 minutes, except in the case of line number 0030 on DN176 (Figures 26), where data was also acquired across survey H12453. Therefore, the applied cast was taken outside of the survey area. Cast frequency with launch data was dictated by changes of more than two meters per second in sound speed at the surface. This did not exceed the Field Procedures Manual’s dictated frequency of four hours. Casts were grouped by vessel and applied within CARIS using the "Nearest in distance within time (4 hours)" profile selection method. Refer to the DAPR for more information on EM710 sound speed correction.26Sound speed cast acquired outside the survey limits of H12452.file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/B_2_7b.jpgAll Equipment and survey methods were used as detailed in the DAPR.B.3.1.1 - Processing EM710 data with CARIS SVC Module At the time of this writing, both Kongsberg and CARIS have confirmed there is an error in the HIPS implementation of the Simrad Sound Velocity Correction (SVC) module, particularly when True Heave is applied to EM710 data (see Supplemental Correspondences - EM710_SV_Error_in_CARIS.pdf and TrueHeave_Error_in_CARIS.pdf). To circumvent this problem, all EM710 data was sound velocity corrected using a custom Simrad SVC-free license, which forced HIPS to use the CARIS (technically, OMG) SVC module. Figure 27 shows a comparison between the best results achieved when using the Simrad SVC module (top), and CARIS SVC module (bottom). It should be noted that a residual artifact still persists within the outerbeams (see Section B.2.5.1 - Kongsberg EM710 Data Artifact), and is being actively investigated by both ship's personnel and appropriate groups ashore. B.3.1.2 - Lines without True Heave and the Heave Offset Vector As mentioned in Section B.3.1.1, all EM710 lines were processed using the CARIS SVC module, with True Heave being applied. When EM710 data is processed in this manner, the heave offset vector within the CARIS HIPS Vessel File (HVF) should be left as zero, see Figure 28 - red highlight. However, if True Heave is unavailable, EM710 data (processed with the CARIS SVC module) with a zeroed heave offset vector will induce an artifact (Figure 29 - bottom). To mitigate this artifact, the offset vector between the ship's reference point and the sonar's transmit array was placed into the heave offset vector of the CARIS HVF (Figure 28 - blue highlight). Five lines in survey H12452 had corrupted True Heave files (DN204 - Line 0008; DN219 - Lines 0011, 0016, 0020; and DN224 - Line 0000), see Figure 30. For these lines with questionable True Heave, the True Heave records were deleted from the HDCS data and were reprocessed with the non-zero heave offset vector, resulting in a marked improvement in the data quality (Figure 29 - top). 27Comparison of gridded data when using the Simrad (top) versus CARIS (bottom) sound velocity correction module. Surfaces are not from survey H12452, but are representative of the artifact.file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/B_3_1_1_Simrad_SVC_2.png28CARIS vessel file showing configurations for both EM710 data logged with True Heave (red) and without True Heave (blue).file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/B_3_1_2_Heave_Offset_HVF.png29Comparison of gridded data when the CARIS sound velocity correction module is used, in the absence of True Heave being applied, both with (top) and without (bottom) a non-zero heave offset vector entered into the CARIS vessel file. Surfaces are not from survey H12452, but are representative of the artifact.file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/B_3_1_1_CARIS_SVC_Heave_Offset.png30Sample line within survey H12452 in which momentary gaps in the True Heave file led to vertical artifacts within the surface. True Heave was removed from all such lines.file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/Figure_B_3_1_2_TrueHeave_broken.pngA new patch test for the Kongsberg EM710 was acquired on DN177 and was processed and entered into the SIS acquisition software on DN178 (See DAPR for additional information). One line from H12452 was acquired prior to this patch test. Patch test correction values, determined in CARIS, were entered into the HVF under DN176 to compensate for alignment biases not accounted for in SIS. patch test2012-06-25Patch test completed to correct for alignment biases.Backscatter data was acquired, but was not formally processed by RAINIER personnel. However, periodic spot checks were performed to ensure backscatter quality. Backscatter data will be sent to NGDC for archival.NOAA Catalogue Control Version 5.2 and NOAA Profile Product Version 2.0.This survey was processed using CARIS HIPS 7.1 - Service Pack 2 - Hotfix 6. To prevent the use of the Simrad SVC, a custom HIPS license (CARIS_Cwsite1_26_04_2013_14_12_21.sit) was used. All other software programs and versions used for data processing are described in the DAPR.H12452_4mCUBE440170NOAA_4mComplete MBESH12452_8mCUBE840170NOAA_8mComplete MBESH12452_16mCUBE1640170NOAA_16mComplete MBESH12452_4m_36Mto80m_FinalCUBE43680NOAA_4mComplete MBESH12452_8m_72Mto160m_FinalCUBE872160NOAA_8mComplete MBESH12452_16m_144to320m_FinalCUBE16144320NOAA_16mComplete MBESH12452_16m_CombinedCUBE1640170NOAA_16mComplete MBESAdditional information discussing the vertical or horizontal control for this survey can be found in the accompanying HVCR.Mean Lower Low WaterDiscrete ZoningSand Point94594509459450.tidFinal ApprovedP133RA2012CORP.zdfFinal2012-08-222012-08-29North American Datum of 1983 (NAD83)The horizontal datum for this project is North American Datum of 1983 (NAD83). To improve positional accuracy, all real time position and attitude data were acquired using POSView and were post processed using precise point positioning (PPP) in POSPac MMS 5.4 (See DAPR for more details). The data on DN194 through DN235 were processed using a version of P1_C1 DCB without an ionospheric model. SBETs and RMS data were applied to all data according to the processes outlined in the DAPR. POSPac SBETs were not applied for DN224 and lines 0009-0017 on DN219 due to a corrupt POS file. DGPS was applied to these lines and no horizontal offsets were evident within the data.Kenai (310 kHz)Cold Bay (289 kHz)Kodiak (313 kHz)DGPS correctors were used for positioning in real time. The DGPS receiver on S221 was not functioning properly for part of this survey, and was providing corrector information intermittently. During these outages, S221 continued to acquire depth data, with the understanding that positional data would be overwritten with more accurate post-processed position information from POSPac (post-processed positional data, i.e. POSPac SBETs). No positional offsets were noted in any of the data on survey H12452. 16587254113500022012-022012-10-302012-10-27Chart comparison procedures were followed as outlined in Section 4.5 of the FPM and Section 8.1.4 - D.1 of the HSSDM, using CARIS HIPS. Chart 16587 is the largest scale chart for this area, and the one used for comparison. Contours and soundings were created from survey H12452 data using CARIS HIPS and visually compared to Chart 16587 soundings (Figures 32 and 33). The surveyed soundings were found to be shoaler than previously charted depths. None of the changes are dangerous to navigation. The Hydrographer recommends that data from H12452 supersede charted data.32Western comparison of charted (16587) depths to those derived from H12452. All soundings are in fathoms. Chart soundings are in a larger type font while survey soundings are denoted in a smaller blue text. Red circles indicated shoaler survey soundings and blue circles mark deeper than charted soundings. file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/Figure_D_1ChartCompare.png33Eastern comparison of charted (16587) soundings to those derived from H12452. All soundings are in fathoms. Chart soundings are in a larger type font, while survey soundings are denoted in a smaller blue text. Red circles indicated shoaler survey soundings and blue circles mark deeper than charted soundings. file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Data_to_Submit_DO_NOT_USE/Processed/Multimedia/Figure_D_1ChartCompareEast.pngUS4AK5XM13500012011-01-312011-01-31falseENC US4AK5XM coincides with raster Chart 16587. The depths and contours on the ENC match the raster, and the comparison between survey H12452 and the ENC is equivalent to the preceding comparison with Chart 16587No AWOIS items exist for this survey.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.The only assigned features for this survey were 11 bottom samples (section A.7), which are included in the Final Feature File.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.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.Richard T. Brennan, CDR/NOAACommanding Officer, NOAA Ship RAINIER2013-05-20Michael O. Gonsalves, LT/NOAAField Operations Officer, NOAA Ship RAINIER2013-05-20James B. JacobsonChief Survey Technician, NOAA Ship RAINIER2013-05-20Brandy E. GeigerSurvey Technician, NOAA Ship RAINIER2013-05-20file:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Descriptive_Report/Appendices/IV%20Tides_and_Water_Levels/Request%20for%20Final%20Approved%20Water%20Levels/Final%20Tides%20Request%20OPR-P133-RA-12,%20Sheet%20H12452.pdffile:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Descriptive_Report/Appendices/IV%20Tides_and_Water_Levels/Request%20for%20Final%20Approved%20Water%20Levels/H12452_Tides_Request.midfile:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Descriptive_Report/Appendices/IV%20Tides_and_Water_Levels/Request%20for%20Final%20Approved%20Water%20Levels/H12452_Tides_Request.miffile:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Descriptive_Report/Appendices/IV%20Tides_and_Water_Levels/Request%20for%20Final%20Approved%20Water%20Levels/H12452_Tides_Request.pdffile:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Descriptive_Report/Appendices/IV%20Tides_and_Water_Levels/Request%20for%20Final%20Approved%20Water%20Levels/H12452_Tides_Request.zipfile:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Descriptive_Report/Appendices/IV%20Tides_and_Water_Levels/Final%20Approved%20Water%20Levels/Final%20Tide%20Note%20for%20OPR-P133-RA-2012,%20Registry%20No%20H12452.pdffile:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Descriptive_Report/Appendices/IV%20Tides_and_Water_Levels/Final%20Approved%20Water%20Levels/H12452.pdffile:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Descriptive_Report/Appendices/V%20%20Supplemental_Correspondence/EM710_SV_Error_in_CARIS.pdffile:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Descriptive_Report/Appendices/V%20%20Supplemental_Correspondence/TrueHeave_Error_in_CARIS.pdffile:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Surveys/H12452/Descriptive_Report/Appendices/III%20Progress_Sketch-Survey_Outline/Survey%20Outline%20for%20sheet%20H12452.pdffile:///H:/OPR-P133-RA-12_Chirikof/H12452/Acquisition_Logs/H12452_2804_Acquisition_Log.xlsmfile:///H:/OPR-P133-RA-12_Chirikof/H12452/Acquisition_Logs/H12452_S221_Acquisition_Log.xlsmfile:///I:/SVP/H12452/2804(RA-6)/H12452_2804_Concatfile:///I:/SVP/H12452/S221/H12452_S221.svpfile:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Project%20Instructions/Final_OPR-P133-RA-12_Chirikof_Island_and_Vicinity_AK_Instructions.pdffile:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Project%20Instructions/Final_OPR-P133-RA-12_Chirikof_Island_and_Vicinity_AK_Instructions.xmlfile:///K:/Projects/2012_Projects/OPR-P133-RA-12,%20Chirikof%20Island/Project%20Instructions/Project%20Layout_April_27_2012.png