OPR-B307-FH-15Rhode Island Sound and ApproachesRhode Island Sound and ApproachesNOAA Ship Ferdinand R. HasslerH128011Nomans LandRhode IslandUnited States200002015LCDR Briana J. Welton, NOAANavigable Area2015-05-222015-06-102015-07-24Multibeam Echo SounderMultibeam Echo Sounder BackscattermetersUniversal Transverse Mercator (UTM)UTCAtlantic Hydrographic BranchNOAASurvey H12801 was conducted in Rhode Island Sound around Nomans Land Island as shown in Figure 1.41.338805555670.883464166741.217369722270.705575The general locality of the H12801 survey area.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/A1_Area_Limits_wText.JPGComplete coverage is not achieved due to the lack of an appropriate near shore vessel. FERDINAND R. HASSLER personnel decided unsafe survey conditions exist inshore of the 30-foot contour. Continuous coverage was extended inshore of the North East sheet limit due to reasonable water depth. In addition to using the 30-foot contour as a boundary for the inshore limit, the ship did not enter the near shore areas along Martha's Vineyard that were marked as fish trap areas due to the potential for submerged gear or structures that could be a danger to the ship.The purpose of this project is to support safe navigation through the acquisition and processing of hydrographic data by updating NOS nautical charting products charts and by the identification and dissemination of dangers to navigation as identified during the course of survey operations.The entire survey is adequate to supersede previous data.Only one holiday was found to exist. This holiday was coincidentally covered by a crossline and no significant features were seen in the crossline data.
All waters in survey areaA) 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 Seciton 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. H12801 was acquired using option A, complete MBES with backscatter.Survey coverage was in accordance with the requirements listed above and in the HSSD.Survey layout for OPR-B307-FH-15 plotted over Chart 13218, 13233, 13237, and 13200.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/A4_Survey_Coverage_wText.JPGS25001199.560000057.55001199.560000057.5504.81500051.92015-06-102015-06-112015-06-122015-06-132015-06-142015-06-162015-06-172015-06-182015-06-252015-06-262015-06-272015-06-282015-07-012015-07-172015-07-182015-07-222015-07-24Mainscheme survey lines were run with a dual-head multibeam echosounder configuration with the exception of DN165, 167, 168, and 169 due to a malfunctioning starboard transducer. To calculate the total linear nautical miles for the survey, statistics were generated using the port transducer data to fully encompass the linear nautical miles surveyed.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.S25037.73.77NOAA Ship FERDINAND R. HASSLER alongside pier at Marine Operations Center - Atlantic.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/B1_Hassler_Picture.pngNOAA Ship FERDINAND R. HASSLER (S250), Shown in Figure 3, acquired all data within the limits of H12801.Reson7125MBESApplanixPOS M/V 320 V5Positioning and Attitude SystemHemisphere MBX-4Positioning SystemBrooke OceanMVP-200Sound Speed SystemAMLMicroCTDConductivity, Temperature, and Depth SensorResonSVP-70Sound Speed SystemMultibeam crosslines were acquired using the RESON 7125 on DN161, DN198, and DN199. A geographic plot of crosslines is shown in Figure 4. Crosslines were filtered to remove soundings greater than 45 degrees from nadir. To evaluate crossline agreement, two 2-meter surfaces were created: one from crossline bathymetry, the other from mainscheme bathymetry. These two surfaces were differenced using CARIS HIPS and SIPS. The statistical analysis of the differences between the mainscheme and crossline surfaces is shown in Figure 5. The average difference between the surfaces is 0.05 meters with a standard deviation of 0.12 meters. 95% of nodes agree within +/- 0.20 meters.
Note: There are some lines that appear to be crosslines but are not included in the crossline analysis because their intended use was ERS checklines.H12801 MBES crossline data shown in purple with mainscheme lines shown in green.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/B2_Crossline_overview.JPGH12801 crossline difference statistics.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/B2_Crossline_Diff_Stats.png0.010.132VDATUMS2501.01.00.5All data were corrected using GPS tides. The VDatum separation model and associated TPU values of 0.01 meters measured uncertainty and 0.132 meters zoning uncertainty were provided by NOAA HSD Operations Branch and used in the calculation of TPU.The areas of overlap between sheet H12801 and its junction sheets, shown in Figures 6, 8, 10, 12, and 14, were reviewed for agreement. Difference surfaces were created from the surface of H12801 and junction survey's bathymetry to assess sounding consistency.H12707400002014NOAA Ship FERDINAND R. HASSLEREThe area of overlap between survey H12801 and its junction H12707, shown in Figure 6 was reviewed in CARIS Subset Editor. The junctioning surface was subtracted from H12801 to assess sounding consistency.
Survey H12707 was conducted by NOAA Ship FERDINAND R. HASSLER in 2014 during the course of Project OPR-B307-FH-14. A difference surface analysis between H12801 and H12707 2-meter resolution combined surfaces, which included over 3.6 million nodes, showed H12801 to be on average 0.01 meters deeper than H12707, with a standard deviation of 0.12 meters. 95% of all differences are less than 0.21 meters from the mean.Junctioning area between survey H12801 and H12707.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/B2_H12801_and_H12707_Diff_Overview.JPGDifferenced surface statistics - H12801 minus H12707.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/B2_H12801_minus_H12707_2m_Combined_Stats.pngH11920100002008NOAA Ship THOMAS JEFFERSONEThe area of overlap between survey H12801 and its junction H11920, shown in Figure 8, was reviewed in CARIS Subset Editor. The junctioning surface was subtracted from H12801 to assess sounding consistency.
Survey H11920 was conducted by NOAA Ship THOMAS JEFFERSON in 2008 during the course of Project OPR-B307-TJ-08. A difference surface analysis between H12801 and H11920 2-meter resolution surfaces, which included over 158 thousand nodes, showed H12801 to be on average 0.07 meters shallower than H11920, with a standard deviation of 0.25 meters. 95% of all differences are less than 0.42 meters from the mean.Junctioning area between survey H12801 and H11920.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/B2_H11920%20Difference.GIFDifferenced surface statistics - H12801 minus H11920.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/B2_H12801_2m_minus_H11920_2m.pngH11922100002008NOAA Ship THOMAS JEFFERSONNWThe area of overlap between survey H12801 and its junction H11922, shown in Figure 10, was reviewed in CARIS Subset Editor. The junctioning surface was subtracted from H12801 to assess sounding consistency.
Survey H11922 was conducted by NOAA Ship THOMAS JEFFERSON in 2008 during the course of Project OPR-B307-TJ-08. A difference surface analysis between H12801 and H11922 2-meter resolution surfaces, which included over 500 thousand nodes, showed H12801 to be on average 0.07 meters deeper than H11922, with a standard deviation of 0.15 meters. 95% of all differences are less than 0.29 meters from the mean.Junctioning area between survey H12801 and H11922.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/B2_H11922%20Difference.GIFDifferenced surface statistics - H12801 minus H11922.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/B2_H12801_minus_H11922_2m.pngH12802400002015NOAA Ship FERDINAND R. HASSLERSThe area of overlap between survey H12801 and its junction H12802, shown in Figure 12, was reviewed in CARIS Subset Editor. The junctioning surface was subtracted from H12801 to assess sounding consistency.
Survey H12802 was conducted by NOAA Ship FERDINAND R. HASSLER in 2015 during the course of Project OPR-B307-FH-15. A difference surface analysis between H12801 and H12802 1-meter resolution surfaces, which included over 2.5 million nodes, showed H12801 to be on average 0.01 meters deeper than H12802, with a standard deviation of 0.13 meters. 95% of all differences are less than 0.27 meters from the mean.Junctioning area between survey H12801 and H12802.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/B2_H12801_and_H12802_Diff_Overview.GIFDifferenced surface statistics - H12801 minus H12802.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/B2_H12801_minus_H12802_1m.pngH12811400002015NOAA Ship FERDINAND R. HASSLEREThe area of overlap between survey H12801 and its junction H12811, shown in Figure 14, was reviewed in CARIS Subset Editor. The junctioning surface was subtracted from H12801 to assess sounding consistency.
A difference surface analysis between H12811 and H12801 2-meter resolution surfaces, which included over 1 million nodes, showed H12811 on average 0.04 meters deeper then H12801, with a standard deviation of 0.11 meters. 95% of all differences are less than 0.22 meters from the mean. These results may differ from the H12811 DR due to the length of time between survey completion.Junctioning area between survey H12801 and H12811.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/B2_H12801_and_H12811_Diff_Overview.JPGDifferenced surface statistics - H12801 minus H12811.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/B2_H12801_2m_minus_H12811_2m.pngSonar system quality control checks were conducted as detailed in the quality control section of the DAPR.Starboard Reson 7125 Hard Drive Failure and Reset ErrorsUpon the start of sheet H12801, the starboard Reson 7125 was experiencing an increasing number of "reset" errors. These errors would produce a gap in the data lasting for approximately 2-3 seconds along track and at times with a frequency of every 30 seconds. The gaps were producing many holidays that were later reacquired, decreasing the efficiency of operations. After communicating the problem to Reson, it was suggested that the Alpha Data Vertex 6 ("AD") card be replaced. After replacing cards, the gaps seemed to appear much more infrequent but still occasionally occurred. The source of the Reson reset problem is still unknown but is manageable in its current state by including the gaps in the holiday acquisition plan.
In addition to the data gaps caused by the reset errors, the starboard Reson 7125 internal hard drive in the Reson processing computer failed which caused the inability to both write to and copy from the drive. The large number of data gaps in combination with the above mentioned hard drive failure forced the ship to operate from DN164 (after line 000_1231) through DN169 using only the port Reson 7125. When the hard drive and AD cards were replaced, the ship resumed acquiring data in dual head mode on DN176.HYPACK Forcing File ExtensionsEvery line acquired in the extents of survey H12801 had two file extensions applied to each filename during acquisition. This resulted in the raw survey lines being named XXX_XXXX.hsx.s7k, which caused issues processing backscatter data with the Fledermaus FMGT software application. The extension .hsx extension was removed for processing.
Sound Velocity EffectsSome areas within sheet H12801 exhibit sound speed artifacts in the outer beams of the swath. The shallow area north of Nomans Land shown in Figure 16 was particularly susceptible to this problem. During routine ship MBES acquisition, the MVP winch was set to limit the tow fish max depth to 5 meters off of the sea floor. In shallow areas, this would result in a cast of about half the water depth and turned out to be insufficient to completely sample the water column. This caused some large refraction artifacts in the outer beams of the swath that were in some cases on the order of 0.50-0.75 meters different than the nadir beam. Areas with gross sound speed issues were cleaned to the extent practicable (without producing holidays in the surfaces).
Figure 17 shows a brief instance of a jump in surface sound speed that correlates to increased outer beam refraction. Data not within specifications were rejected.
Multiple regions in the survey show evidence of outer beam refraction as seen in Figure 18, however, these errors are still within acceptable uncertainty limits as per the 2015 NOAA HSSD. Some areas of the pass north of Nomans Land exhibit SV artifacts due to the MVP not reaching deep enough in the water column.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/B2_Sound_Velocity_a.JPGSurface sound speed affecting outer beams.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/B2_Sound_Velocity_b.JPGGeneral refraction of the outer beams causing striping appearance in surface.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/B2_Sound_Velocity_c.JPGCTD casts using the MVP200 were taken approximately every 15-30 min. Comparisons of the cast-to-cast variation were used to direct cast frequency. The casts were then applied in Caris HIPS and SIPS using the Nearest in Distance Within Time of 4 hours option. All equipment and survey methods were used as detailed in the DAPR.Data Density AnalysisA density analysis was run to calculate the number of soundings per surface node. The results determined that over 99% of all nodes in each finalized surface contain five or more soundings for the 1m and 2m surfaces. The density analysis was executed on nodes which are populated by at least one sounding and did not account for holidays located within the surface. The 0.5m density analysis is also included and shows that both the North and South surfaces fall short of the density requirement. To achieve a useful coverage of the 0.5m surface to assist in capturing least depths of rocky areas, it was necessary to extend it beyond what the density supported. A waiver was granted in this instance by the NOAA HSD Operations Branch and correspondance can be found in Appendix II.Data density analysis for the northern 0.5m finalized surface.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/B2_H12801_MB_50cm_MLLW_North_Final_Density.pngData density analysis for the southern 0.5m finalized surface.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/B2_H12801_MB_50cm_MLLW_South_Final_Density.pngData density analysis for the 1.0m finalized surface.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/B2_H12801_MB_1m_MLLW_Final_Density.pngData density analysis for the 2m finalized surface.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/B2_H12801_MB_2m_MLLW_Final_Density.pngTotal Vertical Uncertainty AnalysisTotal vertical uncertainty analysis was performed using the Finalized CSAR QA tool within Pydro. The resulting statistical analysis found that 100% of nodes in all finalized surfaces within survey H12801 meet the vertical uncertainty standards.Total vertical uncertainty analysis for the northern 0.5m finalized surface.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/B2_H12801_MB_50cm_MLLW_North_Final_TVU_QC.pngTotal vertical uncertainty analysis for the southern 0.5m finalized surface.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/B2_H12801_MB_50cm_MLLW_South_Final_TVU_QC.pngTotal vertical uncertainty analysis for the 1m finalized surface.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/B2_H12801_MB_1m_MLLW_Final_TVU_QC.pngTotal vertical uncertainty analysis for the 2m finalized surface.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/B2_H12801_MB_2m_MLLW_Final_TVU_QC.pngAll data reduction procedures conform to those detailed in the DAPR.All sounding systems were calibrated as detailed in the DAPR.Backscatter was logged in Reson datagram 7008 snippets record in the raw .s7k files. The .s7k files also holds the navigation record and bottom detections for all lines of survey H12801. The files were paired with the CARIS HDCS data, imported and processed using Fledermaus Geocoder Toolbox.
The GSF files containing the extracted backscatter are submitted with the data in this survey. The processed mosaic is saved as a Geo-Tiff and also submitted.CarisHIPS and SIPS9.0.19NOAA Profile Version 5.3.2H12801_MB_50cm_MLLW_NorthCUBE0.57.4638.44NOAA_0.5mComplete MBESH12801_MB_50cm_MLLW_SouthCUBE0.57.9439.19NOAA_0.5mComplete MBESH12801_MB_1m_MLLWCUBE1.06.2937.01NOAA_1mComplete MBESH12801_MB_2m_MLLWCUBE2.07.2035.09NOAA_2mComplete MBESH12801_MB_50cm_MLLW_North_FinalCUBE0.57.4020.00NOAA_0.5mComplete MBESH12801_MB_50cm_MLLW_South_FinalCUBE0.57.8720.00NOAA_0.5mComplete MBESH12801_MB_1m_MLLW_FinalCUBE1.05.9825.00NOAA_1mComplete MBESH12801_MB_2m_MLLW_FinalCUBE2.020.0035.09NOAA_2mComplete MBESH12801_MB_2m_MLLW_CombinedCUBE2.05.9835.09NOAA_2mComplete MBESDue to the nature of the rocky seafloor and scattered boulders in areas on sheet H12801, the 1m surface was not effective in representing the least depth of the bathymetry. Initially, designated soundings were used to force the finalized surface to the least depth of those areas. This resulted in an unmanageable number of designated soundings and was also deemed unreliable at ensuring least depths are represented by the surface. After consulting the HSD Operations project manager for OPR-D307-FH-15 and members of the Atlantic Hydrographic Branch, permission was obtained to create a 0.5m surface for regions where many designated soundings were needed (emails about this topic are included in Appendix II Supplemental Survey Records and Correspondence).
Since the survey was not conducted with the intent to achieve object detection coverage, the data may not fully support a 0.5m surface. Because holidays are present in the 0.5m surface, the 0.5m surface is completely overlapped with the 1m surface. The 0.5m surface's sole purpose is to reach the least depths on pinnacles. The 1m finalized surface depth ranges were also altered from the HSSD 1m depth range specifications of 0-20m to 0-25m to aid in accurately depicting least depths. Density statistics determined from these surfaces can be found in section B.2.9 Data Density Analysis.An example of the 1m surface not reaching rock least depths in ~13m of water.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/B5_1m_not_reaching_pinnacles.jpgAn example of the same location as the previous figure with a 50cm surface better representing least depths on rocks.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/B5_50cm_reaching_pinnacles.jpgFailure to load Delayed HeaveErrors occurred in applying Delayed Heave to data from the port transducer on DN165 resulting in no Delayed Heave applied to the lines for this day. However, this will not affect the data because Smoothed Best Estimate of Trajectories (SBETs) have been applied. In addition to DN165, Delayed Heave was not reapplied to line x000_1547 after reapplying the interpolated SBET. Again, this will not affect the data because of the applied SBET.Total Number of Designated SoundingsThe number of designated soundings in H12801 totaled 361.Additional information discussing the vertical or horizontal control for this survey can be found in the accompanying HSTB Base Station Deployment Report.Mean Lower Low WaterTCARINewport, RI8452660Martha's Vineyard GPS Buoy, MA84488758452660.tidVerified ObservedB307FH2015CORP_rev.zdfPreliminaryB307FH2015_Final.tcFinal2015-07-302015-09-23A final TCARI grid was received for project OPR-B307-FH-15, H12801, during the time period between July 16th and July 26th, 2015. A TCARI grid was possible due to HSTB's water level buoy that was used during the project.VDatum2015_OPR-B307-FH-15_VDatum_NAD83_MLLW_revised.csar2015_OPR-B307-FH-15_VDatum_MLLW_to__NAD83_ReversSEP.csarAll soundings submitted are reduced to Mean Lower Low Water (MLLW) using a VDatum separation model. ERS checklines were run as requested by HSD Operations Branch but were not processed before acquisition was completed. In lieu of processing the ERS checklines, an ERZT separation model was created and compared to the VDatum separation model using a difference surface. A final TCARI grid was used in the creating of the ERZT separation model. The results can be seen in the ERS Memo located in Appendix IV.
A reverse separation model was provided to assist troubleshooting some SBET issues. The SBET issues were corrected either by reprocessing the SBET or by deleting and interpolating through SBET altitude spikes. Further explanation is provided in section C.3.North American Datum of 1983 (NAD83)UTM Zone 19NSingle BaseMartha's Vineyard 1, Martha's Vineyard, MAWMVY1Martha's Vineyard 2, Martha's Vineyard, MAWMVY2Single Base was the primary Post Processed Kinematic (PPK) method used for processing of Applanix TrueHeave data and Smooth Best Estimate of Trajectory (SBET) files. The SBET files have been loaded for all lines in survey H12801 and are used to reduce soundings to MLLW.
HSTB installed two base stations on Martha's Vineyard, MA, that that sent real time position correctors to FERDINAND R. HASSLER during the entire acquisition period via 4G internet service. Details are available in the supplemental HSTB field report in Appendix II.Acushnet, MA (306 kHz)Interpolation of SBETsOn occasion, the SBET altitude exhibited spikes resulting in unacceptably high TVU. In these instances, tools in Pydro's POSPAC Automated QC were used to interpolate the SBET (See Figure 29 for an example). The interpolated SBET was exported out of the POSPAC Automated QC tool, opened in POSPAC MMS, and exported again to ensure the SBET was in the correct datum (NAD83). The new SBET contains the prefix "interpolated" or "export" for easy identification. The following SBETs were interpolated for H12801:
DN 178 All Lines (Port) using interpolated_2015_178_S250P_b
DN 203 Line x000_1547 (Port) using interpolated_export_2015_203_S250P_b.out
DN203 Line x000_1547 (Stbd) using export_2015_203_S250_b.out
An SBET from DN203 shows the spike causing a large vertical offset in the bathymetry.
file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/C3_SBET_Spike.JPGAfter interpolation of the SBET shown in Figure 28, the offset in bathymetry disappears.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/C3_Interpolated_Sbet.JPGVertical OffsetDuring acquisition on H12841 some vertical offsets were observed after GPS tides were applied. The areas affected by the vertical offset were within TVU for the survey and were not investigated further. The POSPAC Automated QC tool was unable to interpolate in these instances. The amount of the offset is approximately 0.15 meters which is within the allowable TVU for the surveyed depths. Examples can be seen from lines acquired on DN163.Subset Editor image of 0.15 meter offset in DN163 data.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/C3_GPS_Tide_Offset.jpgA sounding plot and derived depth contours from the surveyed area to the charted soundings and contours. In general, the depth derived contours align with the charted contours with a few exceptions.13233211040000192011-012015-05-192015-05-23Surveyed soundings and contours agree reasonably well with charted depths and contours within 2-4 ft. The MBES coverage indicates boulders scattered throughout a large portion of the survey in which are not represented by the chart. Figure 32 shows some general disagreements between surveyed depths and depth curves and charted soundings and contours.Areas where surveyed depths and depth curves differ from charted soundings and contours from chart 13233.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/13233_Contours_Comparison.JPG13218213980000422013-072015-03-312015-05-02The differences in 13233 charted 30 and 60 foot contours and surveyed depth curves are shown in Figure 31. Chart 13218 has an additional 90 ft contour and tends to agree with the surveyed contours except some minor differences. Differences are noted in Figure 33.Areas where surveyed depths and depth curves differ from charted soundings and contours from chart 13218.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/13218_overview.JPGUS4MA23M80000272015-04-072015-04-07falseSoundings were extracted from the S-57 file and imported as a point cloud into Caris HIPS and SIPS. The point cloud was differenced with the 2m surface and a TIN was created. From the TIN, an interpolated surface was created (Figure 34). The depth differences range between -6.47 and 3.34 meters (negative meaning survey data is deeper than charted and positive meaning survey data is shoaler than charted). On average, H12801 is -0.97 meters deeper than ENC US5MA23M soundings.Difference Surface of ENC US4MA23M soundings to an interpolated surface minus H12801.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/D1_US4MA23M_Chart_Comparison_Diff_Surf.JPGENC US5MA23M Sounding Comparison Statisticsfile:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/D1_US4MA23M_minus_H12801_2m.pngUS5MA29M4000072015-01-262015-01-26falseSoundings were extracted from the S-57 file and imported as a point cloud into Caris HIPS and SIPS. The point cloud was differenced with the 2m surface and a TIN was created. From the TIN, an interpolated surface was created (Figure 36). The depth differences range between -6.2 and 3.82 meters (negative meaning survey data is deeper than charted and positive meaning survey data is shoaler than charted). On average, H12801 is -0.77 meters deeper than ENC US5MA29M soundings.Difference Surface of ENC US5MA29M soundings to an interpolated surface minus H12801.file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/D1_US4MA29M_Chart_Comparison_Diff_Surf.JPGENC US5MA29M Sounding Comparison Statisticsfile:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/D1_US4MA29M_minus_H12801_2m.pngNo Maritime Boundary Points were assigned for this survey.No charted features exist within the extents of this survey. One uncharted wreck was found within the survey area. Further details can be found in the Final Feature File.3H12801 DtoN Report 12015-09-25One Danger to Navigation Report is included in Appendix II of this report.No shoals or potentially hazardous features exist within the extents of this survey.No channels exist within the extents of 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.
It should be noted that the pass between Nomans Land and Squibnocket Point is a common route for fishing boats and other small recreational vessels.A total of twelve bottom samples, chosen from NOAA HSD Operations Branch suggestions and the hydrographer's analysis of acquired backscatter, were taken within the limits of H12801 and are submitted with the FFF, as shown below in Figure 38. Bottom samples ranged from mud to pebbles. Three attempted bottom grabs yielded no return. These samples are not included in the FFF. The positions of these negative samples are shown below in Figure 39.Positions of 12 bottom samples (shown in black)file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/D1_BottomSamples.GIFPositions of 3 negative samples (circled in black)file:///S:/2015/OPR-B307-FH-15_Rhode_Island_Sound/H12801/Data/Descriptive_Report/Report/Support_Files/D1_NegativeSamples.GIFShoreline verification was not conducted during this project because of the inability to deploy the ship's survey launch due to a damaged davit. Three features from the Composite Source File were disproved using complete multibeam coverage spanning a radius of 60m around the previously charted feature. These features can be found in the FFF with a recommendation to remove from the chart.No prior surveys were available for comparison with this survey.Three navigational buoys existed within the survey limits of H12801 that were visually observed and appeared to be correctly positioned.No overhead features exist within the extents of this survey.No submarine features exist within the extents of this survey.No ferry routes or terminals exist within the extents of this survey.No platforms exist within the extents of this survey.No Significant Features exist within the extents of this survey.No present or planned construction or dredging exist within the survey limits.Due to the large amount of fishing vessel and small boat traffic operating around the shores of Martha's Vineyard and Nomans Land, it's recommended that future surveys are planned to acquire data further inshore of H12801 coverage.No new insets are recommended for this area.Field operations for this hydrographic survey were conducted under the direct supervision of the then Chief of Party, Commander Marc S. Moser, 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, 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.LCDR Briana J. Welton, NOAAChief of Party2016-07-20LT Jon Andvick, NOAAField Operations Officer2016-07-20LT Nick Morgan, NOAASheet Manager2016-07-20OPR-B307-FH-15 Data Acquisition and Processing Report2016-07-222015 Hydrographic Systems Readiness Review Memo2015-07-06