OPR-K371-KR-16Paul L. DonaldsonGulf of MexicoLeidosH12879538 NM South of Calcasieu PassLouisianaUnited States400002016Paul L. DonaldsonBasic Hydrographic Survey2016-05-122016-08-122016-09-29Multibeam Echo SounderSide Scan SonarMultibeam Echo Sounder BackscattermetersUTCAtlantic Hydrographic BranchContract: EA-133C-14-CQ-0033/T-0002.
Contractor: Leidos, 221 Third Street, Newport, RI 02840 USA.
Subcontractors: Divemasters, Inc., 15 Pumpshire Road, Toms River, NJ 08753; OARS, 8705 Shoal Creek Blvd, Suite 109, Austin, TX 78757.
Leidos Doc. 17-TR-006.
All times were recorded in UTC.
Data were collected in UTM Zone 15.ContractorThe area surveyed was a section of the Gulf of Mexico south of Calcasieu Pass, LA (Figure 1).29.16018093.4444729.08522093.25355
H12879 Survey Bounds
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Survey limits were acquired in accordance with the requirements in the Project Instructions and the NOS Hydrographic Surveys Specifications and Deliverables (HSSD).The purpose of this survey is to update existing NOS nautical charts. This project is located in a highly trafficked critical area south of the Louisiana coast as designated in the 2012 NOAA Hydrographic Survey Priorities.The entire survey is adequate to supersede previous data.Leidos warrants only that the survey data acquired by Leidos and delivered to NOAA under Contract EA-133C-14-CQ-0033 reflects the state of the sea floor in existence on the day and at the time the survey was conducted.
H12879 was surveyed in accordance with the following documents:
1. Project Instructions, OPR-K371-KR-16, dated 12 May 2016
2. NOS Hydrographic Surveys Specifications and Deliverables (HSSD), March 2016
3. OPR-K371-KR-16 Statement of Work, dated 12 May 2016All waters in survey area.Either A) Complete MBES with backscatter, OR B) 100% SSS with concurrent set line spacing MBES with backscatter. Note: Complete MBES is sufficient for both determination of least depth identified with SSS and for disproving a feature – 100% SSS is insufficient to disprove a feature. Refer to Section 6.1.2 of the HSSD to confirm proper SSS acquisition parameters. Gaps in SSS coverage should be treated as gaps in MBES coverage and addressed accordingly.Leidos chose to achieve the coverage requirement using 100% side scan sonar with concurrent set line spacing multibeam echo sounder with backscatter. Survey coverage was in accordance with the requirements in the Project Instructions and the HSSD.
Final Bathymetry Coverage for H12879
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M/V Atlantic Surveyor000001061.75053.470000001061.75053.4705.04600044.072016-08-122016-08-162016-08-172016-08-182016-08-192016-08-202016-08-212016-08-222016-08-232016-08-242016-08-252016-08-262016-08-272016-09-29Leidos used their ISS-2000 software on a Windows 7 platform to acquire these survey data. Survey planning and data analysis were conducted using the Leidos SABER software on Red Hat Enterprise 6 Linux platforms. L-3 Klein 3000 side scan data were collected on a Windows 7 platform using L-3 Klein’s SonarPro software. Subsequent processing and review of the side scan data, including the generation of coverage mosaics, were accomplished using SABER.
A detailed description of the systems and vessel used to acquire and process these data is included in the Data Acquisition and Processing Report (DAPR) for OPR-K371-KR-16, delivered on 13 January 2017. There were no variations from the equipment configuration described in the DAPR.M/V Atlantic Surveyor1109The M/V Atlantic Surveyor was used to collect multibeam sonar (RESON SeaBat 7125 SV), side scan sonar (L-3 Klein 3000), and sound speed data during twenty-four hours per day survey operations.
A detailed description of the vessel used is included in Section A of the DAPR.RESONSeaBat 7125 SVMBESL-3 Klein3000SSSApplanixPOS/MV 320 V5Positioning and Attitude SystemTrimbleProbeaconPositioning SystemODIM Brooke OceanMVP-30Sound Speed SystemA detailed description of the equipment installed is included in Section A of the DAPR.There were 53.47 linear nautical miles of crosslines and linear nautical miles of mainscheme lines surveyed on H12879. This resulted in crossline mileage of approximately 1061.75 of the mainscheme mileage, which meets the requirement to achieve approximately four percent of mainscheme mileage for a complete coverage multibeam survey (Section 5.2.4.3 of the HSSD). H12879 requirements were for complete coverage, Option B, based on the classifications defined in Section 5.2.2 of the HSSD; “100% side scan sonar coverage with concurrent multibeam bathymetry collection with complete coverage multibeam developments (i.e. 1m grid resolution in 0-20m depth range) of contacts and features.”
The mainscheme lines were oriented 90°/270° and spaced 80 meters apart. Crosslines were oriented 0°/180° and spaced 1500 meters apart. Refer to the “Multibeam Processing Log” section within Separates I for information on the delineation of mainscheme and crossline data files.
In the field, hydrographers conducted daily comparisons of mainscheme to near nadir crossline data to ensure that no systematic errors were introduced, and to identify potential problems with the survey systems. After the application of all correctors and completion of final processing in the office, separate one-meter grids were built. One grid contained the full valid swath (±60° from nadir, Class 2) of mainscheme multibeam and the other included only the near nadir swath (±5° from nadir, Class 1) crossline data. Difference grids were then generated by subtracting one grid from the other.
The SABER Frequency Distribution Tool was used to analyze the difference grids. All comparisons fell within the requirement defined in Section 5.2.4.3 of the HSSD, which states that at least 95% of the depth difference values are to be within the maximum allowable total vertical uncertainty. Figure 3 summarizes the comparison results. See Separates II for a complete discussion of the analysis and tabular results.
Summary of Crossing Analysis
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The Total Propagated Uncertainty (TPU) model that Leidos has adopted had its genesis at the Naval Oceanographic Office (NAVOCEANO), and is based on the work by Rob Hare and others (“Error Budget Analysis for NAVOCEANO Hydrographic Survey Systems, Task 2 FY 01”, 2001, HSRC FY01 Task 2 Final Report). Once the TPU model is applied to the GSF bathymetry data, each beam is attributed with the horizontal uncertainty and the vertical uncertainty at the 95% confidence level. For specific details on the use and application of the SABER Total Propagated Uncertainty model, see Section B.1 in the DAPR.
The vertical and horizontal uncertainty values that were estimated by the TPU model for individual multibeam soundings varied little across the dataset, tending to be most affected by beam angle. During application of horizontal and vertical uncertainties to the GSF files, individual beams where either the horizontal or vertical uncertainty exceeded the maximum allowable IHO S-44 5th Edition Order 1a specifications were flagged as invalid. As a result, all individual soundings used in development of the final CUBE depth surface had modeled vertical and horizontal uncertainty values at or below the allowable IHO S-44 5th Edition, Order 1a uncertainty.
During the creation of the CUBE surface, two separate vertical uncertainty surfaces are calculated by the SABER software. One surface contains the standard deviation of all soundings that are contributing to the CUBE hypothesis (Hyp. StdDev), and the other contains the average of the vertical uncertainty of all soundings contributing to the CUBE hypothesis (Hyp. AvgTPE). A third vertical uncertainty surface is generated from the larger value of these two uncertainties at each node and is referred to as the Hypothesis Final Uncertainty. For specific details on this process, see Section B.2 of the DAPR.
The final one-meter PFM CUBE surface contained final vertical uncertainties that ranged from 0.470 – 0.712 meters. The IHO Order 1a maximum allowable vertical uncertainty was calculated to range between 0.554 to 0.576 meters, based on the minimum CUBE depth (18.385 meters) and maximum CUBE depth (22.037 meters). The SABER Check PFM Uncertainty function was used to highlight all instances in the Hypothesis Final Uncertainty surface where a given node exceeded the IHO Order 1a allowable vertical uncertainty for the CUBE depth at that node. The final one-meter PFM CUBE surface contained 19 individual CUBE nodes with final vertical uncertainties that exceeded IHO Order 1a allowable vertical uncertainty. Of the 19 nodes that exceed the IHO Order 1a allowable vertical uncertainty for the CUBE depth, 15 nodes were associated with a single scour while the remaining four nodes were associated with a single feature (Feature 01).
The SABER Frequency Distribution Tool was used to review the Hypothesis Final Uncertainty surface within the final one-meter PFM grid. The results show that in the final one-meter PFM grid, 99.99% of all nodes had final uncertainties less than or equal to 0.500 meters. An analysis of H12879 junctions with contemporary surveys was performed. Figure 4 shows the general locality of H12879 as it relates to the contemporary sheets for which junction analysis was performed. Table 6 provides details for each contemporary sheet junction analysis performed. See Separates II for a complete discussion of the junction results and tabular listings.
General Locality of H12879 with Contemporary Surveys
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H10890200001999C and C Technologies, Inc.EH12879 junctions with H10890 to the east; 95.08% of the comparisons agreed within ±0.540 meters. H12876400002016Leidos, Inc.NWH12879 junctions with H12876 to the northwest; 100.00% of the comparisons agreed within ±0.221 meters. H12877400002016Leidos, Inc.NH12879 junctions with H12877 to the north; 100.00% of the comparisons agreed within ±0.350 meters. H12878400002016Leidos, Inc.WH12879 junctions with H12878 to the west; 100.00% of the comparisons agreed within ±0.430 meters. Sonar system quality control checks were conducted as detailed in Section A.5, Multibeam Systems and Operations, of the DAPR.None ExistThere were no conditions or deficiencies that affected equipment operational effectiveness.ExistLocalized weather events produced a difference in water levels between the survey area and the water level gauge. The artifact was seen in the multibeam CUBE surface and generally ranged between 10 to 15 centimeters when present (Figure 5). Additionally, positional scatter resulting from normal DGPS variability was sometimes visible in the sounding data for discrete features with multiple passes. Figure 6 represents small positional differences of 1.6 meters over a discreet object from three separate passes. This horizontal offset was not always present as depicted in Figure 7, which shows two passes over a distinct object which align quite well (within 0.3 meters). These occasional vertical and horizontal offsets observed within H12879 were within the IHO Order 1a allowable vertical and horizontal uncertainty for these water depths.
CUBE Depth Delta and Heave Artifacts Resulting From Local Weather Events
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DGPS Positional Variation Between Passes
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No DGPS Positional Variation Between Multiple Passes and Multiple Headings
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On the M/V Atlantic Surveyor, the MVP-30 was used to collect sound speed profile (SSP) data. SSP data were obtained at intervals frequent enough to meet depth accuracy requirements. Section 5.2.3.3 of the HSSD requires that if the sound speed measured at the sonar head differs by more than two meters/second from the commensurate profile data, then another cast shall be acquired. There were times when the sound speed values exceeded the two meters/second threshold due to the local temporal and tidal variability. During these times, several profiles were acquired and reapplied in an effort to reduce these effects. The product of this effort resulted in the final data bearing no significant artifacts due to sound speed differences.
All sound speed profiles applied for online bathymetry data collection were acquired within the bounds of the survey area. Please refer to the DAPR for specific details regarding acquisition (Section A.7) and application (Section C.1.3) of sound speed profiles.
Confidence checks of the sound speed profile casts were conducted by comparing at least two consecutive casts taken with different SVP Smart Sensors. Five sound speed confidence checks were conducted during H12879 and the results can be found in Separates II within the “Comparison Cast Log” section.
All individual sound speed profile files are delivered with the H12879 data and are broken out into sub-folders, which correspond to the purpose of each cast. Also, all individual sound speed profiles for H12879 have been concatenated into four separate files based on the purpose of the cast, provided in CARIS format files (.svp), and delivered under (H12879/Data/Processed/SVP/CARIS_SSP) on the delivery drive. In addition sound speed data for OPR-K371-KR-16 were submitted to NCEI following the NetCDF template format as specified in Section 8.3.6 of the HSSD. Refer to Separates II for more details.All equipment and survey methods are detailed in the DAPR.Multibeam Coverage AnalysisLeidos chose to achieve the coverage requirement using 100% side scan sonar with concurrent set line spacing multibeam echo sounder with backscatter. To achieve this coverage, the M/V Atlantic Surveyor used a towed L-3 Klein 3000 side scan sonar set to a 50-meter range scale. Mainscheme line spacing was 80 meters, which ensured 100% side scan coverage.
Both the Project Instructions and the HSSD stated that 100% side scan was insufficient to disprove a charted feature. Therefore, Leidos reviewed the Composite Source File (CSF), BSB charts, and ENC charts and completed an additional 100% side scan coverage, and resulting multibeam coverage over common charted objects not found during survey in order to verify disproval. A radius was determined from the Project Instructions, which stated, “In the case of the unassigned offshore oil platforms within the survey area, should the field unit observe that the feature is not visible, then a formal disproval is required. For the purposes of disproval, charted features labeled with a “PA” will have a search radius of 160 meters, a “PD” will have a search radius of 240 meters, and all other features without a position qualifier will have a search radius of 80 meters.” For the wellheads assigned in the final CSF file, coverage requirements for disproval were provided via email from NOAA on 16 June 2016 stating “If the obstruction is not found, in cases where 100% SSS with concurrent multibeam is being used as the primary coverage technique, a 50m disproval search radius using a technique described in Section 7.3.4 is necessary.”
The SABER Gapchecker routine was used to flag multibeam data gaps within the CUBE surface. Additionally, the entire surface was visually scanned for holidays at various points during the data processing effort. Additional survey lines were run to fill any holidays that were detected. A final review of the CUBE Depth surface of the one-meter PFM containing all multibeam data showed that there were a few instances where a three by three node gap exists. However, these were not considered holidays in the final multibeam CUBE surface as these instances generally resulted from either the holiday line data being slightly offset from the original line due to vessel line steering, or the swath width of the holiday lines being reduced compared to the original line due to water level differences.
All grids were examined for the number of soundings contributing to the chosen CUBE hypotheses for each node by running SABER’s Frequency Distribution Tool on the Hypothesis Number of Soundings (Hyp # Soundings) surface of the one-meter CUBE PFM. The Hyp # Soundings surface reports the number of soundings that were used to compute the chosen hypothesis. Analysis of the H12879 final one-meter PFM grid revealed that 98.23% of all nodes contained five or more soundings; satisfying the requirements for complete coverage surveys, Option B, as specified in Section 5.2.2.3 of the HSSD.All data reduction procedures conform to those detailed in the DAPR.All sounding systems were calibrated as detailed in the DAPR.2017-01-13Side Scan Coverage Analysis: For all details regarding side scan data processing, see Section B.3 of the DAPR. Leidos chose to adhere to the coverage requirements in the Project Instructions with 100% side scan coverage with concurrent set line spacing MBES with backscatter. Both the Project Instructions and the HSSD stated that 100% side scan was insufficient to disprove a charted feature. Therefore, 100% side scan coverage was collected and verified for the entire survey area, and an additional 100% coverage was collected over charted objects that were not found, and CSF assigned objects, to verify disproval. Leidos generated two separate coverage mosaics at one-meter cell size resolution as specified in Section 8.2.1 of the HSSD. The first 100% and second 100% disproval coverage mosaics were independently reviewed using tools in SABER to verify data quality and swath coverage. The SABER Gapchecker routine was used to flag data gaps within each of the 100% side scan sonar coverage mosaics. Additionally, the entirety of each SSS surface was visually scanned for holidays at various points during the data processing effort. Additional survey lines were run to fill any holidays that were detected. Both coverage mosaics are determined to be complete and sufficient to meet the requirements contained within the Project Instructions. The mosaics are delivered as TIFF (.tif) images with accompanying world files (.tfw), refer to Table 7.
Multibeam Echo Sounder Seafloor Backscatter: In accordance with the HSSD and Project Instructions, Leidos collected multibeam backscatter with all GSF data acquired by the RESON SeaBat 7125 SV. The multibeam settings used were checked to ensure acceptable quality standards were met and to avoid any acoustic saturation of the backscatter data. The multibeam backscatter data acquired were written to the GSF in real-time by ISS-2000 and are delivered in the final GSF files for this sheet. Per the Project Instructions, backscatter data were not processed by Leidos and no additional products were produced.LeidosSABER5.2.0.19.02LeidosSABER5.2.0.19.02NOAA Extended Attribute File V5-4. The primary data processing software used for both bathymetry and imagery was SABER. There were no software configuration changes after the DAPR was submitted.H12879_MB_1m_MLLW_Final_1of2BAG119.26422.037N/AConcurrent
set line
spacing
MBESH12879_MB_1m_MLLW_Final_2of2BAG118.38520.945N/AConcurrent
set line
spacing
MBESH12879_SSS_1m_100SSS Mosaic (.tif;.tfw)100N/A100% SSSH12879_SSS_Disproval SSS Mosaic (.tif;.tfw)100N/A200% SSS Charted Object DisprovalA PFM CUBE Depth surface was used to assess and document multibeam survey coverage. The CUBE depth is populated with either the node’s chosen hypothesis or the depth of a feature or designated sounding set by the hydrographer, which overrides the chosen hypothesis. The range of CUBE depths in H12879 was from 18.385 meters (60.318 feet, 0.470-meter uncertainty) to 22.037 meters (72.300 feet, 0.480-meter uncertainty). Complete Coverage Section 5.2.2.3 of the HSSD requires a one-meter grid resolution for depths ranging from zero meters to 20 meters, and a two-meter grid resolution for depths ranging from 18 meters to 40 meters. Based on the depth range of H12879, Leidos asked NOAA for permission to deliver the entire surface of H12879 at the one-meter grid resolution. On September 22, 2016 the NOAA Hydrographic Survey Department Operations branch granted a waiver to Leidos for OPR-K371-KR-16, allowing Leidos to submit surfaces for H12879 that are gridded at 1m resolutions despite depths being deeper than 20m. This waiver is included within the supplemental correspondence (Appendix II) of this Data Report.
The final gridded bathymetry data are delivered as Bathymetric Attributed Grids (BAG). The BAG files were exported from the CUBE PFM grid as detailed in Section B.2.5 of the DAPR.No vertical or horizontal controls were established, recovered, or occupied during data acquisition for OPR-K371-KR-16, which includes H12879. Therefore, a Horizontal and Vertical Control Report was not required.Mean Lower Low WaterCalcasieu Pass, LA8768094Discrete Zoning8768094_verified_01June16_to_04Oct16.tidVerified ObservedK371KR2016CORP.zdfFinal1957-08-131957-08-15No final tide note was provided by the NOAA Center for Operational Oceanographic Products and Services (CO-OPS). Leidos is not required to have a final tide note from CO-OPS for H12879 however, a final tide note has been provided by Leidos in Appendix I.
The Tides Statement of Work specified NOAA tide station 8768094 Calcasieu Pass, LA as the source for water level correctors for OPR-K371-KR-16. A full explanation of the tide zone assessment is detailed in Section C.4 of the DAPR. For H12879, 8768094 Calcasieu Pass, LA was the source of all final verified water level heights for determining correctors to soundings. All data for H12879 were contained within two tide zones (WGM393 and WGM398) which were provided from NOAA.
Leidos did not revise the delivered tide zones for tide station 8768094 Calcasieu Pass, LA as the water level zoning parameters in the file K371KR2016CORP.zdf, provided by National Ocean Service (NOS) were deemed adequate for the application of observed verified water levels. As a result, they were accepted as final and applied to all H12879 bathymetry data. ERS via Constant Separation ModelNorth American Datum of 1983 (NAD83)UTM Zone 15, NorthSingle BaseEnglish Turn, LA (293 kHz)Angleton, TX (301 kHz)Aransas Pass, TX (304 kHz)Please refer to the DAPR for details regarding all antenna and transducer offsets.
During survey data acquisition, the ISS-2000 real-time system provided a continuous view of the positioning comparison between the POS/MV and the Trimble DGPS. An alarm was triggered within ISS-2000 if the comparisons were not within an acceptable range. Any soundings with total horizontal uncertainties exceeding the maximum allowable IHO S-44 5th Edition Order 1a specifications were flagged as invalid and therefore were not used in the CUBE Depth calculations. The chart comparisons were conducted using the Leidos SABER software to view the BSB raster charts with overlain data for H12879 such as the CUBE surface, selected soundings, contacts, and features. Charting recommendations for depths follow Section 5.1.2 of the HSSD where depths and uncertainties are to be rounded by standard arithmetic rounding (round half up).
For ENC comparisons, a combination of CARIS’ EasyView and SABER were used.
United States Coast Guard (USCG) District 8 Local Notice to Mariners publications were reviewed for changes subsequent to the date of the Project Instructions and before the end of survey (as specified in Section 8.1.4 of the HSSD). The Notice to Mariners reviewed were from 22/16 (01 June 2016) until week 40/16 (05 October 2016).
H12879 data meet data accuracy standards and bottom coverage requirements. Recommend updating the common areas of all charts using data from this survey. Charting recommendations for all features found, and updates to charted features, are documented in the H12879 S-57 FFF. Additional charted objects such as submarine pipelines and platforms are discussed in later sections.11330195250000222013-042017-03-182017-03-18Chart 11330 covers the H12879 survey area in its entirety.
CUBE depths within sheet H12879 were generally one to three feet shoaler than surveyed depths.
The charted 60 foot contour within the northern extents of the survey bounds was not found except for one small discrete location where sixty foot depths were found approximately 700 meters north of the charted contour location.
All new uncharted features found, and updates to charted features, are documented in the H12879 S-57 Final Feature File (FFF).US3GC02M250000272017-02-28false2014-10-27ENC US3GC02M covers the H12879 survey area in its entirety.
CUBE depths within sheet H12879 agreed with the charted depths across most of the survey area and were generally within ±1 meter of the charted depths.
The charted 18.2 meter contour across the northern section of the survey was not observed within the extents of hydrography.No Maritime Boundary Points were assigned for this survey.Two charted objects were present within the survey bounds, a charted dangerous wreck with depth unknown and a charted 17.600 meter obstruction. No significant features were found within the search radius for either of the charted features. The details resulting from final processing of the data and recommendations are captured in the H12879 S-57 FFF.See the H12879 S-57 FFF for all the details and recommendations regarding new uncharted features investigated.0There were no Danger to Navigation Reports (DTON) submitted for H12879.
Per guidance from Atlantic Hydrographic Branch (AHB), via email correspondence 20 January 2016, exposed pipelines should not be submitted as DTONs but as Feature Reports, in S-57 format. Leidos submitted one Feature Report in S-57 format to AHB, 01 March 2017, which AHB forwarded to the Office of Coast Surveys Navigation Manager. The Feature Report contained four separate sections of exposed pipeline. Figure 8 provides a list of Feature Reports and their associated Feature number and object class in the H12879 S-57 FFF.
Feature Report Submitted to AHB
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There were no significant shoals or hazardous features within the area covered by H12879 other than those
discussed in Sections D.1.5 and D.1.6.There were no channels within the area covered by H12879. In accordance with both the Project Instructions and Section 7.2.2 of the HSSD, bottom characteristics were obtained for H12879. Bottom characteristics were acquired at six locations, five of which were assigned in the Project Reference File (PRF) by NOAA. Leidos did not modify any bottom sample locations from the locations proposed by NOAA in the PRF. A sixth bottom sample was collected after review of the side scan data indicated a change in reflectivity which was approximately 3.8 kilometers from the closest assigned bottom sample location. Bottom characteristics collected during H12879 are included in the H12879 S-57 FFF, named H12879.FFF.000, within the Seabed Area (SBDARE) object and are classified according to the requirements set forth in Appendix H of the HSSD.All features within the CSF were resolved. There were no assigned features inshore of the NALL. Junction analysis with prior surveys H10890, H12876, H12877, and H12878 (collected in 1999 and 2016, respectfully) were conducted, and the results are presented in Section B.2.3 of this Data Report and Separates II.There were no aids to navigation that fell within the area of H12879. There were no overhead features within the H12879 survey area.Five pipeline (PIPSOL) objects (Features 5-9) are delivered in the S-57 FFF to represent sections of pipeline found, utilizing both multibeam and side scan data, within the bounds of H12879. See Section D.1.6 for additional information. Additional charted pipelines fall within the survey coverage; however, the multibeam and side scan data do not show evidence of them.No ferry routes or terminals exist within the H12879 survey area.There were no assigned offshore platform objects in the CSF, OPR-K371-KR-16_CSF_Version2.000, provided on 16 June 2016, which fell within the H12879 survey area. However, there were four charted platforms within the H12879 SOW area; each of these was associated with an assigned obstruction (wellhead) within the OPR-K371-KR-16_CSF_Version2.000 file. The four charted platforms were not found during survey operations and were covered by 200% side scan and resulting multibeam over an area with a radius of at least 80 meters. There was no evidence of the platforms existence in the side scan or multibeam data and no platforms were visible above the waterline. See the S-57 FFF, H12879.FFF.000, Offshore Platform (OFSPLF) objects, for details and charting recommendations on each charted platform.During data acquisition on H12879 there were intermittent local weather events producing increased winds and sea state. Occasionally during the localized weather events, the water levels within the survey area differed slightly (10 to 15 centimeters) from the water level gauge located at Calcasieu Pass, LA. In addition, during these intermittent weather events, some residual heave artifacts resulting from increased sea states were present. The observed heave artifacts ranged from 10 to 15 centimeters. However, the vertical offsets and heave artifacts observed were within the IHO Order 1a allowable vertical and horizontal uncertainty for the H12879 water depths. See Section B.2.6 for more information regarding the water level offsets and heave artifacts.
No abnormal seafloor or environmental conditions, as defined in Section 8.1.4 of the HSSD, exist within the H12879 survey area.No construction or dredging exists for the H12879 survey.No new survey recommendations are made for the area surrounding the H12879 survey area.Designated SoundingsDesignated soundings were used to help better preserve the shallowest sounding relative to the computed depth surface. Separate flags exist in the Generic Sensor Format (version 3.06) for designated soundings and features. All depths flagged as features and designated soundings override the CUBE best estimate of the depth in the final BAG files. Both the designated sounding and feature flags, as defined within GSF, are mapped to the same HDCS flag when ingested into CARIS (PD_DEPTH_DESIGNATED_MASK).
No GSF designated sounding flags were set for H12879. Only GSF feature flags were set on significant features within H12879, and all information is contained in the H12879 S-57 FFF.
Final Feature S-57 FileIncluded with H12879 delivery is the S-57 FFF, H12879.FFF.000. Details on how this file was generated and quality controlled can be found in Section B.2.6 of the DAPR. The S-57 FFF delivered for H12879 contains millimeter precision for the value of sounding (VALSOU) attribute. As specified in Section 8.2 of the HSSD, the S-57 FFF is in the WGS84 datum and is unprojected with all depth units in meters. All significant, and recommended for charting, features found in H12879 are included within the S-57 FFF.
In accordance with the HSSD, Leidos addressed all assigned objects within the bounds of H12879 from the provided CSF S-57 file in the S-57 FFF.
For each feature contained in the FFF (S-57), the Feature Correlator Sheet was exported as an image file (.jpg) and is included in the S-57 FFF under the NOAA Extended Attribute field “images”.Side Scan Sonar Contacts S-57 FileIncluded with the H12879 delivery is the Side Scan Sonar Contact S-57 File, H12879.SSCon.000. Details on how this file was generated and quality controlled can be found in Section B.3.5 of the DAPR. As specified in Section 8.2 of the HSSD, the S-57 feature file is in the WGS84 datum and is unprojected with all depth units in meters.
Side scan sonar contacts were investigated and confirmed using SABER Contact Review. All side scan contacts are retained within the Side Scan Sonar Contact S-57 File. For each contact included in this S-57 file, a JPEG image of the side scan contact is included under the NOAA Extended Attribute field “images”.Coast Pilot Review ReportA Coast Pilot Review Report for OPR-K371-KR-16 was not required per guidance from the NOAA COR (see 06 June 2016 email in Appendices II Supplemental Survey Records and Correspondence). The Coast Pilot was reviewed for the port of call and areas frequently transited, and no changes are recommended.Assigned WellheadsOn 16 June 2016, NOAA delivered OPR-K371-KR-16_CSF_Version2.000 which contained fourteen wellhead features within the H12879 survey bounds requiring investigation (See Appendix II). All wellhead locations were covered in accordance with Section 7.3.4 of the HSSD with a minimum of 200% side scan data and resulting multibeam data. A minimum of a 50-meter disproval search radius was covered as specified in the correspondence dated 16 June 2016. No wellheads were found at the fourteen assigned locations surveyed as part of H12879. No inset recommendations are made for the area covered by the H12879 survey.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 BAG files, this Descriptive Report, and all accompanying records and data are approved. All records are forwarded for final review and processing to the Processing Branch.The survey data meets or exceeds requirements as set forth in the NOS Hydrographic Surveys Specifications and Deliverables, Project Instructions, and the OPR-K371-KR-16 Statement of Work. 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. Previously submitted deliverables for OPR-K371-KR-16 are provided in the table below.Paul L. DonaldsonChief Hydrographer2017-04-21OPR-K371-KR-16_DAPR.pdf2017-01-13H12875_DR.pdf2017-01-13H12876_DR.pdf2017-02-03H12877_DR.pdf2017-03-03H12878_DR.pdf2017-03-31OPR-K371-KR-16_Marine_Mammal_Observation_Log_1of2.pdf2017-04-11OPR-K371-KR-16_Marine_Mammal_Observation_Log_2of2a.pdf2017-04-12OPR-K371-KR-16_Marine_Mammal_Observation_Log_2of2b.pdf2017-04-12OPR-K371-KR-16_20170412.zip
(NCEI Sound Speed Data)
2017-04-12