OPR-K414-NRT4-2016Galveston Bay EntranceGalveston, TXNRT4H123871The regional Navigation Manager has received pilot and port authority requests for hydrographic surveys in Galveston Bay and vicinity. The main purpose of this project is to survey the newly charted barge channels along the main Houston Ship Channel. Another priority area is a section of a proposed anchorage south of the Outer Bar Channel that has not been recently surveyed. This area is located in the southwest corner of sheet H12387. NOAA's Marine Chart Division has also requested investigation of shoreline and numerous charted features in the area, to help reduce localized chart clutter. The shoreline investigation will use the CSF file and the nautical charts to do the investigations. This survey is intended to supersede all bathymetry, seafloor features, and bottom characteristics within the assigned survey area as defined by these instructions for updating of NOAA charts 11324, 11326, 11327 and 11328.Galveston Bay EntranceTexasUnited States100002016Dan JacobsNavigable Area2016-09-292016-08-192016-09-20Multibeam Echo SoundermetersUniversal Transverse Mercator (UTM)UTCPacific Hydrographic BranchThe purpose of this survey is to provide contemporary surveys to update National Ocean Service (NOS) nautical charts. All separates are filed with the hydrographic data. Any revisions to the Descriptive Report (DR) generated during office processing are shown in bold red italic text. The processing branch maintains the DR as a field unit product, therefore, all information and recommendations within the body of the DR are considered preliminary unless otherwise noted. The final disposition of surveyed features is represented in the OCS nautical chart update products. All pertinent records for this survey, including the DR, are archived at the National Centers for Environmental Information (NCEI) and can be retrieved via http:// www.ncei.noaa.gov/.NOAAObject Detection MBES operations for H12387 commenced on 19AUG2016. The last day of acquisition was 20SEP2016. Hydrography proved challenging for this sheet as NRT4 was short staffed and sea conditions often precluded quality data collection in this turbulent bottleneck of Galveston Bay, TX. Per project instructions, NRT4 "squared off" H12387 MBES coverage on 20SEP2016, with the intent to cease operations entirely if unsatisfactory seas persisted. As such, NRT4 completed only one-fifth of the assigned survey sheet, an area of approximately 1 square nautical mile. Note: as the Tide Note shows, Hydrography for this area included one extra day, DN264. This was a blunder on the part of the Hydrographer as data collected on that day facilitated a crossline comparison for a separate project.29.344041972294.668853138929.317597833394.7035533056H12387 Survey Sheet Limits and MBES Coverage, Chart 11324, 39th Ed.SupportFiles\H12387_Sheet_Limits_and_Cov_final.bmpOnly one-fifth (approximately 1 square nautical mile) of hydrography was completed for Sheet H12387 on account of heavy seas and personnel staffing challenges.H12387 Survey Sheet Limits and MBES CoverageSupportFiles\H12387_Sheet_Limits_and_Cov.bmpThe regional Navigation Manager has received pilot and port authority requests for hydrographic surveys in Galveston Bay and vicinity. The main purpose of this project is to survey the newly charted barge channels along the main Houston Ship Channel. Another priority area is a section of a proposed anchorage south of the Outer Bar Channel that has not been recently surveyed. This area is located in the southwest corner of sheet H12387. NOAA's Marine Chart Division has also requested investigation of shoreline and numerous charted features in the area, to help reduce localized chart clutter. The shoreline investigation will use the CSF file and the nautical charts to do the investigations. This survey is intended to supersede all bathymetry,seafloor features, and bottom characteristics within the assigned survey area as defined by these instructions for updating of NOAA charts 11324, 11326, 11327 and 11328.The entire survey is adequate to supersede previous data.Hydrographic data quality meets or exceeds density and IHO quality standards despite area coverage deficiency. Coverage requirements were not fully obtained due to excessive wave energy at Galveston Bay's entrance and/or personnel staffing issues. Weather and sea conditions precluded safe collection of good quality data on most days, August through November. Additionally, 7 density holidays and two much larger were discovered implementing the NOAA Pydro density holiday QC tool, Version 1. See following graphics, below.H12387 HolidaysSupportFiles\H12387_Holidays.bmpCoverage requirement table was not filled out with information from Project Instructions. The coverage table should have been populated with the following information from the Project Instructions: Water Depth: All waters in survey area Coverage Required: Object Detection Coverage accomplished using either: A) Object detection MBES depth and backscatter data, or B) 200% SSS coverage with concurrent set line spacing SBES depth data or MBES depth and backscatter data, except as noted below. Object detection MBES depth and backscatter data inside the barge lanes and 50 meters shoreward from the outer limits of the barge lanes, extending as necessary to define the 12 ft contour. Refer to HSSD Section 5.2.2.1 and 5.2.2.2 Due to safety reasons the 3m contour was not achieved. Field unit provided explanation of NALL via email correspondence with reviewer which can be found in the \Descriptive_Report\Appendices\II_Supplemental_Survey_Records___Corresponence\ folderH12387 Survey Sheet Limits and MBES CoverageSupportFiles\H12387_Sheet_Limits_and_Cov.bmpS1211011603200000100480011603200000100480000000.922016-08-192016-08-222016-08-232016-08-252016-09-082016-09-092016-09-132016-09-16Object Detection MBES operations for H12387 commenced on 19AUG2016 and concluded on 16SEP2016. Note: The tide note shows, Hydrography for this area included one extra day, DN264 (20SEP2016). This was a blunder on the part of the Hydrographer. Data collected on that day facilitated a crossline comparison with historical soundings for a separate project. Units in Table 2 above for LNM for MBES Mainscheme and SBES/MBES Crosslines are in Meters. MBES Mainscheme = 62.65 LNM and SBES/MBES Crosslines = 5.43 LNM.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.S1211100.5S1211SupportFiles\SeaArk.bmpS1211 is a 30 foot SeaArk Commander. Its beam is 8 feet and draft is nominally 2 feet. S1211 is powered by two Honda 200 horsepower, 4 cycle, gasoline outboards.KongsbergEM3002MBESEdgetech4125SSSPlease reference NRT4's 2016 DAPR for equipment specifications.The following three additional equipment "major systems" should be listed. These were found in the DAPR but not listed in the field Descriptive Report: Applanix - POS MV5 - Positioning and Attitude System YSI - CastAway - Conductivity, Temperature, and Depth Sensor Odom - Digibar Pro - Sound Speed SystemIn accordance with the 2014 Field Procedures Manual, 5.43 LNM of MBES crosslines (8 percent of the total mainscheme line lengths) were collected and compared to object detection, mainscheme coverage using the CARIS HIPS Surface Difference Tool. Soundings demonstrated good agreement as 95 percent of crossline depths (2 sigma) laid within 0.20 meters of the mean, 0.00 meters. See figures, attached.H12387 MBES Crosslines (brown) vs H12387 MBES Mainsceme Lines (green)SupportFiles\Crosslines_Graphic.jpgH12387 Crossline Depths vs Mainscheme Depths.SupportFiles\H12387_Crossline_compare_Computation.png0.160.00TCARITide uncertainty for the project area was 0.08 meters at one sigma (See graphic below). This value was doubled to 0.16 meters during TPU calculation as Caris expects a two sigma value. Total Vertical Uncertainty (TVU) was calculated implementing Pydro's QC tools. The finalized, 50cm grid passed with 99 percent of all grid nodes falling inside IHO Order 1a's error budget. Likewise, object detection sounding density requirements were satisfied as 99 percent of finalized, 50cm grid nodes contained at least 5 soundings per node.Tide Uncertainty, Galveston Bay, TX. Values scaled to one sigma.SupportFiles\TideError_K414NRT42015.pngTotal Vertical Uncertainty calculation for H12387 Finalized CUBE Surface.SupportFiles\H12387_MBES_50cm_MLLW_Final.QAv1.tvu_qc.pngSounding Density Statistics for H12387 Finalized CUBE Surface.SupportFiles\H12387_MBES_50cm_MLLW_Final.QAv1.density.pngH12387 50cm grid nodes were compared to historic (2013) H12388 50cm grid nodes invoking the CARIS "Surface Differencing" tool. A -0.6 meter trend was noted throughout the resultant surface at this junction area. See graphics below for specific CARIS statistics.H12388 (green colored coverage) Junction to H12387 (rainbow colored coverage)SupportFiles\Junction_H12388.pngJunction to H12388, Surface Difference StatisticsSupportFiles\surf_diff_stats_final.bmpSonar system quality control checks were conducted as detailed in the quality control section of the DAPR.Systematic artifact near nadir, EM3002Overpowered beams near nadir were problematic throughout this survey. Please reference NRT4's 2016 DAPR for specific information regarding this well-known, MBES, systematic error which is unique to Kongsberg's EM3002 model, particularly over soft seabeds.None ExistThere were no other factors that affected corrections to soundings.Sound speed casts were taken every 4 hours in accordance to the Field Procedures Manual. Sound speed casts were taken at 4 hour intervals or less as sea characteristics (turbidity and thermal layering) dictated.H12387 is a MBES Object Detection survey, entirely. Ship traffic and restricted maneuverability deterred towed side scan operations.All data reduction procedures conform to those detailed in the DAPR.All sounding systems were calibrated as detailed in the DAPR.Backscatter was not collected for this survey.Backscatter was acquired in accordance with the PI'sNOAA Profile Version 5.3.3.NOAA Profile Version 5.3.3 was installed to CARIS Bathy Database version 4.0.9. and implemented for H12387 feature management processing. (CARIS_Support_Files_Ver_5_3_2.) H12387_MBES_50cm_MLLW_FinalCUBE0.55.3320.76NOAA_0.5mObject DetectionH12387_MBES_1m_MLLW_FinalCUBE118.0020.76NOAA_1mObject DetectionTwo finalized CUBE surfaces were generated to account for H12387's maximum depth of 20.76 meters in accordance with 2014 Field Procedures Manual, Paragraph 4.2.1.1.1. The overlapping depth ranges induced 5 to7 1meter X 1meter "orphaned" surfaces to materialize in the H12387_MBES_1m_MLLW_Final surface. Note that "H12387_MBES_50cm_MLLW_Final" met density and IHO requirements throughout the entire range of gridded depths. As such, no survey statistical analysis accompany the 1 meter finalized surface.H12387 Orphaned Surfaces, 1 meter gridSupportFiles\H12387_1m_Surface_Speckles.pngAdditional information discussing the vertical or horizontal control for this survey can be found in the accompanying HVCR.Mean Lower Low WaterTCARI8770613.tidFinal Approved8771013.tidFinal Approved8771341.tidFinal Approved8771450.tidFinal ApprovedK414NRT42016.tcFinal2016-12-052016-12-07TCARI grid "K414NRT42016.tc" was used as the final grid for project OPR-K414-NRT4-16, H12387, during the time period between August 19 - September 20, 2016.North American Datum of 1983 (NAD83)UTM NAD83 Zone 15 North.Angleton, Texas, DGPS, 301kHzAngleton, TX DGPS, 301kHz was used for differential GPS corrections on all days of survey. No outages were reported for the duration of the survey. No HVCR was submitted as part of the H12387 package.In the figure below, survey soundings that were deeper by more than 2 feet as compared charted (11324) soundings were circled in blue. Survey soundings which ranged between +/- 2 feet of charted soundings were circled in green. Survey soundings that were shoaler by 2 feet or more were circled in red. Sheet H12387 exhibited some deepening trends near the end and seaward of the S. Jetty.H12387 Survey Soundings vs Charted SoundingsSupportFiles\H12387_chart_comparison.bmp11324125000392015-052016-12-132016-11-26Sheet H12387 exhibited some deepening trends near the end and seaward of the S. Jetty.Applicable ENC not listed: US5TX53M, Scale: 1:25000, Edition: 52, Update Application Date: 12/26/2017, Issue Date: 12/26/2017No Maritime Boundary Points were assigned for this survey.No charted features exist for this survey.One sounding was designated over an obstruction situated at 29-19-43N 094-21-26W. Least depth is 39 feet below MLLW. No Danger to Navigation Reports were submitted for this survey.No shoals or potentially hazardous features exist for this survey.Channels, designated anchorages, precautionary areas, safety fairways, traffic separation schemes, pilot boarding areas, and/or channel and range lines exist within the survey limits, but were not investigated.Bottom samples were assigned for this survey, but were not acquired.Shoreline was assigned in the Hydrographic Survey Project Instructions or Statement of Work, but was not investigated.Prior survey comparisons exist for this survey, but were not investigated.No Aids to navigation (ATONs) exist for this survey.ATON's exist for the survey but were not investigated.No overhead features exist for this survey.No submarine features 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.No present or planned construction or dredging exist within the survey limits.H12387 project boundary was only 20 percent esonified with object detection MBES. A larger survey vessel or AUV is recommended for this turbulent area of Galveston Bay. 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, 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.Dan JacobsChief of Party2017-01-25Data Acquisition and Processing Report2017-01-25