OPR-T381-RA-22 Mariana Islands Western Pacific Ocean NOAA Ship Rainier (S221) H13576 6 Rota Island Northern Mariana Islands United States 10000 2022 Héctor L. Casanova, CAPT/NOAA Navigable Area 2022-01-07 2022-04-14 2022-09-01 Multibeam Echo Sounder Multibeam Echo Sounder Backscatter meters UTC Pacific Hydrographic Branch Any revisions to the Descriptive Report (DR) applied during office processing are shown in red italic text. The DR is maintained as a field unit product, therefore all information and recommendations within this report are considered preliminary unless otherwise noted. The final disposition of survey data is represented in the NOAA nautical chart products. All pertinent records for this survey are archived at the National Centers for Environmental Information (NCEI) and can be retrieved via https://www.ncei.noaa.gov/. Products created during office processing were generated in NAD83 (MA11) UTM 55N, MLLW. All references to other horizontal or vertical datums in this report are applicable to the processed hydrographic data provided by the field unit. CC0-1.0 (NOAA Field Units) CC0-1.0 https://creativecommons.org/publicdomain/zero/1.0/ https://creativecommons.org/publicdomain/zero/1.0/legalcode These data were produced by NOAA and are in the public domain within the United States. NOAA waives any potential copyright and related rights in these data worldwide through the Creative Commons Zero 1.0 Universal Public Domain Dedication (CC0). NOAA The survey area is referred to as H13576, "Rota Island" (Sheet 6) in the Project Instructions. The assigned survey encompassed an estimated 1055 square nautical miles and is located in the Northern Mariana Islands. 14.615268055555555 144.66476480555556 13.84497838888889 145.4637433611111 H13576 assigned survey area. (Chart 81004) file:///M:/OPRT381RA22/Surveys/H13576/01_HDR/Reports/Descriptive_Report/SupportFiles/H13576_Assigned_Sheet_Limits.PNG Data were acquired within the assigned survey limits as required in the Project Instructions and HSSD unless otherwise denoted. The originally assigned survey limits extended into areas with depths greater than RAINIER could efficiently acquire quality multibeam data. Therefore we requested, and the Operations Branch approved, that we survey to the 1,500 meter depth contour and not beyond. See Supplemental Records for more information. H13576 surveyed depth contour (Chart 81004). file:///M:/OPRT381RA22/Surveys/H13576/01_HDR/Reports/Descriptive_Report/SupportFiles/H13576_Surveyed_Depth_Contour.PNG The ecosystem surrounding the Commonwealth of the Northern Mariana Islands (CNMI) is experiencing stress imposed by climate change and other environmental factors. This survey is part of an extensive hydrographic project intended to map the bathymetry and habitat around the CNMI in support of nautical charting and habitat mapping. With collaboration and partnership of the National Centers for Coastal and Ocean Science (NCCOS), the NOAA Coral Reef Conservation Program (CRCP), and the National Marine Fisheries Service (NMFS), this survey will study the health of coral reef systems, ocean chemistry, and fisheries habitat. This team has developed a strategy to map the waters from nearshore to depths greater than 1000 meters. Within the project area, the ship's crew will collect bathymetric data to update charts and backscatter data to characterize habitat. Visiting scientists from NCRMP will perform coral reef assessment dives and conduct other oceanographic observations. Data collected during this mission are pivotal to long-term biological and oceanographic monitoring of coral reef ecosystems around CNMI. Data from this survey will add to information collected during prior monitoring and mapping projects. Oceanographic and ecological time series data will allow scientists to evaluate potential changes in environmental conditions and coral reef health in the Mariana Archipelago. This will enable federal and state resource managers to more effectively conserve coral reef ecosystems of CNMI and to manage ecosystem services. Data collected will also support monitoring components of the CRCP Coral Reef Ecosystem Integrated Observing System.This modern hydrographic survey will address gaps in the Seabed 2030 project, provide critical data to update National Ocean Service (NOS) nautical charting products, identify hazards, and improve maritime safety. Survey data from this project are intended to supersede all prior survey data in the common area. The entire survey is adequate to supersede previous data. Pydro QC Tools (v.3.4.7) Grid QA (v.6) was used to analyze H13576 multibeam echosounder (MBES) data density. The submitted H13576 finalized variable-resolution (VR) surface met HSSD density but not full coverage resolution requirements as shown in the histograms below. For project OPR-T381-RA-22, Resolution Requirements graphs produced by Pydro’s Grid QA tool have been showing relatively low percentages of grid nodes meeting full coverage resolution requirements. The likely cause of this issue is RAINIER’s use of 64m grids in depths greater than 1,000 meters to maintain a reasonable data density. Since the Grid QA tool was written to match the HSRR specifications with a maximum 32m grid in all waters greater than 640m, RAINIER grids created using the 64m increase in resolution will always fail the resolution requirements check in areas exceeding 1,000 meters. This will of course decrease the percentage of grid nodes meeting coverage resolution requirements. For surveys with a large percentage of area greater than 1,000 meters in depth, this reduction can be significant. The OCS QC tools team has been made aware of this issue and are trying to work out a solution for this deviation from the specifications. See the Supplemental Records of the sheet submission for more information. Pydro derives plot showing HSSD density compliance of H13576 finalized variable-resolution MBES data. file:///M:/OPRT381RA22/Surveys/H13576/01_HDR/Reports/Descriptive_Report/SupportFiles/H13576_MB_VR_MLLW_Final.QAv6.density.png Pydro derived plot showing HSSD complete coverage resolution compliance of H13576 finalized variable-resolution MBES data. file:///M:/OPRT381RA22/Surveys/H13576/01_HDR/Reports/Descriptive_Report/SupportFiles/H13576_MB_VR_MLLW_Final.QAv6.pct_res.full_cov.png All waters in survey area Complete Coverage (Refer to HSSD Section 5.2.2.3) The entire extent of the assigned sheet limits was not surveyed for H13576 due to time constraints and adverse weather conditions on the winward side of the island of Rota. Multibeam echosounder coverage was acquired to the inshore limit of hydrography, the Navigable Area Limit Line (NALL), within a majority of the assigned sheet limits. The NALL is defined as the most seaward of the following: the surveyed 10 meter depth contour, the line defined by the distance seaward from the observed MHW line which is equivalent to 0.8 millimeters at chart scale (the assigned sheet limits closely reflect this), or the inshore limit of safe navigation. H13576 MBES coverage and assigned survey limits for Rota Island. (Chart 81004) file:///M:/OPRT381RA22/Surveys/H13576/01_HDR/Reports/Descriptive_Report/SupportFiles/H13576_Survey_Coverage.PNG S221 0.0 704.59 0.0 0.0 0.0 0.0 0.0 47.87 0.0 2803 0.0 11.98 0.0 0.0 0.0 0.0 0.0 1.84 0.0 2804 0.0 60.56 0.0 0.0 0.0 0.0 0.0 1.95 0.0 0.0 777.12 0.0 0.0 0.0 0.0 0.0 51.66 0.0 6.23 0 0 0 0 1055.9 2022-04-14 2022-04-15 2022-04-16 2022-04-17 2022-04-18 2022-04-19 2022-05-09 2022-05-11 2022-05-12 2022-05-14 2022-05-29 2022-05-30 2022-05-31 2022-06-16 2022-07-12 2022-08-04 2022-08-18 2022-08-24 2022-08-25 2022-09-01 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. S221 70.4 4.7 2803 8.8 1.1 2804 8.8 1.1 NOAA Ship RAINIER S221 file:///M:/OPRT381RA22/Surveys/H13576/01_HDR/Reports/Descriptive_Report/SupportFiles/Rainier_in_Honolulu.jpg NOAA Ship RAINIER Survey Launch 2803 file:///M:/OPRT381RA22/Surveys/H13576/01_HDR/Reports/Descriptive_Report/SupportFiles/Launch.jpg All data for survey H13576 were acquired by NOAA Ship RAINIER, survey launch 2803, and survey launch 2804. Survey launches 2803 and 2804 verified shoreline features. All vessels acquired MBES bathymetry, backscatter imagery, and sound speed profiles. Positioning and Attitude System Applanix POS MV 320 v5 MBES Kongsberg Maritime EM 710 MBES Kongsberg Maritime EM 2040 Sound Speed System ODIM Brooke Ocean MVP200 Conductivity, Temperature, and Depth Sensor Sea-Bird Scientific SBE 19plus Sound Speed System Teledyne RESON SVP 70 Sound Speed System Lockheed Martin Sippican Deep Blue XBT NOAA Ship RAINIER and launches collected 51.7 nautical miles of multibeam crosslines, approximately 6.23 percent, across a range of depths in the maincheme data. The Compare Grids function in Pydro Explorer was used to analyze the finalized VR surfaces of H13576 mainscheme only and crossline only data. Pydro determined that 99.5 percent of nodes met allowable uncertainties. For additional results, see plots below. H13576 crossline surface overlaid on mainscheme tracklines (Chart 81004). file:///M:/OPRT381RA22/Surveys/H13576/01_HDR/Reports/Descriptive_Report/SupportFiles/H13576_Crosslines.PNG Pydro derived plot showing absolute difference statistics of H13576 mainscheme to crossline data. file:///M:/OPRT381RA22/Surveys/H13576/01_HDR/Reports/Descriptive_Report/SupportFiles/H13576_MB_VR_MLLW_XL-H13576_MB_VR_MLLW_MS_depth_delta.png Pydro derived plot showing percentage-pass value of H13576 mainscheme to crossline data. file:///M:/OPRT381RA22/Surveys/H13576/01_HDR/Reports/Descriptive_Report/SupportFiles/H13576_MB_VR_MLLW_XL-H13576_MB_VR_MLLW_MS_fracAllowErr_Freq.png ERS via VDATUM 0.0 0.11 S221 N/A 1 4 0.05 2803, 2804 3 N/A N/A 0.05 Total Propagated Uncertainty (TPU) values for survey H13576 were derived from a combination of fixed values for equipment and vessel characteristics, as well as from field assigned values for sound speed uncertainties. Tidal uncertainty was provided in the project instructions for the NOAA vertical datum transformation model used for this survey. In addition to the usual a priori estimates of uncertainty, real-time and post-processed uncertainty sources were also incorporated into the depth estimates of this survey. Real-time uncertainties for position, navigation, attitude, and vessel motion data from Applanix POS MV were applied during acquisition and initially in post-processing. POSPac SBET and RMS files were later applied in CARIS HIPS to supersede POS MV uncertainties associated with GPS height and position. Uncertainty values of the submitted finalized grids were calculated in Caris using "Greater of the Two" of uncertainty and standard deviation (scaled to 95%). Grid QA within Pydro QC Tools was used to analyze H13576 TVU compliance. H13576 met HSSD requirements in 99 percent of grid nodes, which is shown in the histogram plot below. Pydro QC Tools 3.7.0 Grid QA was used to analyze H13576 multibeam echosounder (MBES) data density. The submitted H13576 (VR) Variable- Resolution surface met HSSD uncertianty requirements shown in the histograms below. Pydro derived plot showing compliance of H13576 finalized variable-resolution MBES data. file:///M:/OPRT381RA22/Surveys/H13576/01_HDR/Reports/Descriptive_Report/SupportFiles/H13576_MB_VR_MLLW_Final.QAv6.tvu_qc.png Survey H13576 junctions with two other surveys from project OPR-T381-RA-22, sheets H13571 and H13573. Reference the respective Descriptive Report (DR) for the junction analysis of the remaining survey from OPR-T381-RA-22. H13576 Junctions (Chart 81004). file:///M:/OPRT381RA22/Surveys/H13576/01_HDR/Reports/Descriptive_Report/SupportFiles/H13576_Junction.PNG H13573 10000 2022 RA N The junction with survey H13573 encompasses approximately 6.61 square nautical miles along the northern border of coverage for H13576. The compare grids function of Pydro Explorer derived a difference surface from H13576 variable-resolution surface and H13573 variable-resolution surface. Pydro Compare Grids showed that 99.5 percent of nodes in the overlapping area met NOAA allowable error standards. Analysis of the difference surface indicated that there is a 0.14 meter average difference between the two surveys. For additional results, see figures below. H13576 and H13573 fraction of allowable error junction surface (Chart 81004). file:///M:/OPRT381RA22/Surveys/H13576/01_HDR/Reports/Descriptive_Report/SupportFiles/H13576_Junction_Surface.PNG Pydro derived plot showing absolute difference statistics of the junction between H13576 and H13573 variable resolution surface. file:///M:/OPRT381RA22/Surveys/H13576/01_HDR/Reports/Descriptive_Report/SupportFiles/H13576_MB_VR_MLLW_Final-H13573_MB_VR_MLLW_FINAL_depth_delta.png Pydro derived plot showing percentage-pass volume of the junction between H13576 and H13573 variable resolution surface. file:///M:/OPRT381RA22/Surveys/H13576/01_HDR/Reports/Descriptive_Report/SupportFiles/H13576_MB_VR_MLLW_Final-H13573_MB_VR_MLLW_FINAL_fracAllowErr_Freq.png H13571 5000 2022 RA S Refer to H13571 Guam Island Descriptive Report for additional junction details. Sonar system quality control checks were conducted as detailed in the quality control section of the DAPR. None Exist There were no conditions or deficiencies that affected equipment operational effectiveness. None Exist There were no other factors that affected corrections to soundings. Sound Speed Cast Frequency: Sound Speed Cast Frequency: At least one cast every four hours or as needed. A total of 30 sound speed profiles ("casts") were acquired for this survey at discrete locations within the survey area at least one every four hours, when significant changes in surface sound speed were observed, or when operating in a new area. Sound speed profiles were obtained using Sea-Bird 19plus SEACAT Profilers on launches and ODIM Brook MVP200 and Lockheed Martin XBT on the the ship. All casts were concatenated into a master file and applied to MBES data using the "Nearest distance within time" (4 hours) profile selection method. Due to the lack of multimission work around Rota, hydrographic data collection "Nearest in time" profile selection method were used. The lack of multimission work around Rota data collection by transit was the optimal strategy. With limited opportunity to collect sound speed information due to time constraints and equipment issues, it was necessary to use a different method of processing casts to correct sound speed issues. H13576 sound speed cast locations (Chart 81004). file:///M:/OPRT381RA22/Surveys/H13576/01_HDR/Reports/Descriptive_Report/SupportFiles/H13576_Cast_Locations.PNG All equipment and survey methods were used as detailed in the DAPR. All data reduction procedures conform to those detailed in the DAPR. All sounding systems were calibrated as detailed in the DAPR. Raw backscatter data were acquired as .all files logged during MBES operations and subsequently processed by Rainier personnel. The .GSF files created during processing and backscatter mosaic data has been delivered with this report. Backscatter processing procedures are described in the DAPR. H13576 multibeam acoustic backscatter overview. (Chart 81004) file:///M:/OPRT381RA22/Surveys/H13576/01_HDR/Reports/Descriptive_Report/SupportFiles/H13576_Backscatter.PNG CARIS HIPS and SIPS 11.4.6 QPS FMGT 7.10.0 NOAA Profile 2022v2 H13576_MB_VR_MLLW_Final CARIS VR Surface (CUBE) Variable Resolution 6.78 2624.98 NOAA_VR Complete MBES H13576_MB_VR_MLLW CARIS VR Surface (CUBE) Variable Resolution 6.78 2624.98 NOAA_VR Complete MBES Submitted H13576 surfaces were generated using NOAA recommended parameters for density-based (Ranges) Caris variable-resolution bathymetric grids. Per correspondence with the Project Manager, the submitted surfaces were generated with the updated Range/Resolution file, NOAA_DepthRanges_CompleteCoverage_2022_RA, that includes 64 meter grids for depths exceeding 1,000 meters. See Project Correspondence for more information. Pydro QC Tools Flier Finder v.3.7.0 was used with default settings to identify "fliers" in the finalized H13576 variable-resolution surface. Obvious noise was rejected by the hydrographer in Caris Subset Editor. After several iterations of data cleaning and running the tool, the program identified 3,620 potential fliers in the submitted surface. Subset analysis of the remaining potential fliers revealed them to be false positives. Pydro QC Tools Holiday Finder v.3.7.0 was used with default settings for full coverage to find holidays in the finalized H13576 variable-resolution surface. Holiday Finder detected 3 holidays in the Complete Coverage surface. Of the 3 holidays, two are caused by bathymetric slopes and the other is caused by incomplete coverage. Additional information discussing the vertical or horizontal control for this survey can be found in the accompanying DAPR. Mean Lower Low Water ERS via VDATUM OPR-T381-RA-22_GuamCNMI_EC_ERDTM2021_NAD83(MA11)-MHW.csar OPR-T381-RA-22_GuamCNMI_EC_ERDTM2021_NAD83(MA11)-MLLW.csar All submitted H13576 MBES data were vertically referenced to the ellipsoid. VDATUM models included with the Project Instructions were used for referencing H13576 data to MLLW and MHW. North American Datum 1983 (MA11) Projected UTM 55 RTX Precise Positioning-Real Time Extended (PP-RTX) processing methods were used in Applanix POSPac MMS (v8.5) software during post-processing horizontal correction of submitted H13576 MBES data. The Wide Area Augmentation System (WAAS) was used for real-time horizontal control during data acquisition. There are several reported depths charted near the Island of Rota. Complete multibeam coverage in these depths to supersede reported depths. US2SP01M 931650 19 2021-09-07 2021-09-07 US5SP04M 25000 5 2021-02-03 2021-02-03 No shoals or potentially hazardous features exist for this survey. An unassigned anchorage exists outside the harbor on the western side of Rota. Of the area surveyed there were no DTONs or obstructions observed in the anchorage. Western Rota anchorage area (ENC US5SP04M). file:///M:/OPRT381RA22/Surveys/H13576/01_HDR/Reports/Descriptive_Report/SupportFiles/H13576_Anchorage.PNG No uncharted 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. Multiple assigned ATONs were visually confirmed. Overnight ship survey of offshore regions limited visual observation, and previous reporting on inaccuracy of charted location for Fish Aggregating Devices indicated possible removal or loss of unconfirmed markers. ATON Fish Aggregating Devices (FADs) (ENC US2SP01M). file:///M:/OPRT381RA22/Surveys/H13576/01_HDR/Reports/Descriptive_Report/SupportFiles/H13576_ATONs.PNG No Maritime Boundary Points were assigned for this survey. No bottom samples were required for this survey. No overhead features exist for this survey. No submarine features exist for this survey. No platforms exist for this survey. No ferry routes or terminals exist for this survey. No abnormal seafloor or environmental conditions exist for this survey. No present or planned construction or dredging exist within the survey limits. No new surveys or further investigations are recommended for this area. No new ENC scales 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 Specifications and Deliverables, 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. Héctor L. Casanova, CPT/NOAA Chief of Party 2022-09-08 Collin H. Walker, LT/NOAA Field Operations Officer 2022-11-10 James B. Jacobson Chief Survey Technician 2022-11-10 Christina L. Brooks Sheet Manager 2022-11-10