No Maritime Boundary Points were assigned for this survey.No bottom samples were required for this survey.No new insets are recommended for this area.The hydrographer recommends that this area be resurveyed regularly due to the significant change in depths from sediment migration observed over the project timeline.Evidence of large and quickly moving sediment waves were visible in the MBES data during acquisition. Refer to section B.2.6 of this report for additional information.One bridge exists in the H13191 survey area. The Project Instructions required that this feature be scanned with a mobile lidar system during survey operations and that the published clearance height be compared to the surveyed clearance. The surveyed overhead clearance was determined using LAS data acquired with the Riegl VUX 1HA mobile mapping system using ERS methods and the NOAA provided custom separation model. The clearance was determined relative to the Mississippi River Low Water Reference Plane (2007). The bridge clearance was computed using Orbit 3DM Feature Extraction Pro (version 19.7), which includes an automated bridge clearance module specifically designed to compute bridge clearance heights. This functionality is typically used in the roadway transportation industry, but with cooperation from DEA, Orbit GT enhanced the software to operate on bridges spanning waterways relative to chart datum. The automated bridge clearance module required a LAS dataset relative to chart datum and an input polygon defining the area of interest where a clearance should be determined. Using the LAS data as a horizontal reference for the bridge structure, DEA created the input polygons, limiting the bounds of the polygon to areas spanning water, excluding land, bridge piers, and bridge fenders. Both the Raster Nautical Chart (RNC) and ENC for this area include charted clearance heights for bridges and cables. The charted heights for all overhead features are identical on the RNC and ENC, though the ENC does not note the vertical datum for the assigned overhead features. The vertical datum for overhead features listed on the RNC is the Mississippi River 1927 High Water Plane (HWP), which is over 44 feet above LWRP at Baton Rouge, LA. In order to make clearance heights more meaningful to chart users and ease the burden for the mariner to compute clearances from local water level gauge data, the hydrographer recommends charting all clearance heights relative to LWRP, not HWP. Water level data available for this stretch of the river are published by USACE relative to an approximation of LWRP. Other river systems, like the Columbia River in Oregon and Washington, use the low water gradient datum (chart datum) for charting of soundings and heights. The Veteran's Memorial Bridge (also referred to as the Gramercy Bridge) is charted at mile 145.9 AHOP. Figure 34 includes a comparison of surveyed clearance heights relative to LWRP to charted clearance heights relative to HWP for the bridge. Figure 35 shows a 3D view of surveyed clearance heights using the minimum value of the bridges relative to LWRP. The FFF includes BRIDGE area features that have been segmented based on the clearance analysis input polygons which include surveyed clearance heights relative to LWRP as depicted in Figure 34. Figure 36 illustrates clearance heights for the Veteran's Memorial Bridge (Gramercy Bridge) published by the United States Coast Guard. These heights are referenced to the Reserve gauge (01260) operated by USACE, which provides river levels 1.76 feet higher than LWRP. The ENC does not include the name of the Veteran's Memorial Bridge in the feature’s object name field. The Hydrographer recommends adding the bridge name to the ENC. A clearance board was not located on the Veteran's Memorial Bridge during survey operations, so the hydrographer was unable to perform a check of the minimum clearance by comparing LAS data on the bridge height clearance board to the surveyed clearance. There are seven minor overhead cables, in navigationally insignificant areas between piers and dolphins that were identified from the mobile lidar system. These overhead cables have been included in H13191 FFF with a description of ‘New’. Though not specified in the Project Instructions, the clearance heights of these features were able to be determined with the MMS system and have been included in the vertical clearance attributes for the features. These features are included in the FFF to aid in the survey review and chart compilation process and are included in the FFF with a recommendation attribute of ‘For info only’. Clearances on overhead cables were determined by using CARIS Base Editor to the identify the valid LAS point with the lowest elevation at each cable crossing. SupportFiles\H13191_Gramercy Bridge_2D.pngVeteran's Memorial Bridge Charted Clearance ComparisonSupportFiles\H13191_Gramercy Bridge_3D.pngVeteran's Memorial Bridge Clearances (view looking upriver)SupportFiles\Gramercy Bridge_USCG.pngVeteran's Memorial Bridge (Gramercy Bridge) USCG Published ClearancesAids to Navigation (AtoNs) were investigated using mobile lidar and visual observations. AtoNs that were missing, damaged, or not serving their intended purpose were reported to the USCG via email on August 23, 2019, with additional items submitted November 7, 2019. Due to the large number of AtoNs requiring reporting, email was used for reporting instead of using the USCG Navigation Center’s Online ATON Discrepancy Report as specified in the HSSD. This method was approved by the HSD Project Manager for this hydrographic survey. A copy of the email submittals are included in Appendix II. AtoNs have been included in the sheet’s FFF with appropriate comments and recommendations.There is one ferry route that exists within the survey limits of H13191. The ferry route has not been included in the FFF as specified in the feature’s CSF investigation requirements. The Edgard Landing to Reserve Ferry Landing (138.1 AHOP) is no longer in service. The ferry route was closed permanently on July 31, 2013. This was confirmed visually in the field and published by the Louisiana Department of Transportation and Development (DOTD). The hydrographer recommends removing the route from the ENC. No platforms exist for this survey.No dredging or construction was observed within the survey limits during survey operations.All submarine features were investigated entirely using object detection MBES coverage. The OPR-J347-HR-18 Project Instructions required that all revetments within the survey area be investigated and delineated in the FFF if detected in the MBES data. In most areas, revetments or sections of revetments are visible in the MBES data and surfaces. In areas where the charted revetments are not visible, the hydrographer is unable to determine if the revetment mats are not visible because they are no longer present, or if they have been buried by sediment. Revetments mats visible in MBES data and extending beyond the limits of the PRF revetment polygons have been included in the FFF as obstruction area features. The VALSOU of each area obstruction has been populated with the minimum gridded depth within the obstruction polygon. The HSD Project Manager and AHB personnel provided input on portrayal of revetments in the FFF. Correspondence related to this guidance is included in Appendix II. There are eight submerged cable and pipeline areas charted in the survey extents of H13191, where anchoring, trawling, and dragging are restricted. These precautionary areas were surveyed using object detection MBES coverage techniques and carefully reviewed for any pipelines or cables that were exposed and pose a risk to navigation. Survey H13191 has six new pipeline sections included in the FFF. All pipelines located within the survey limits were submitted to the Bureau of Safety and Environmental Enforcement (BSEE). A pipeline report included in Appendix II, was submitted to the BSEE on August 21, 2019, reporting sections of exposed or unburied pipeline visible in the MBES data. The report indicates the positions of the start and end points of sections of what appear to be exposed pipelines based on interpretation of multibeam data. It is possible that some of the reported items include submerged outfalls and other linear features with a signature of a pipeline that are not associated with oil and gas infrastructure. Due to the inability to accurately depict the location and orientation of all exposed pipelines with a single line segment, these features have been included in the FFF should further action be required after survey submittal. It is not the hydrographer’s intention that these pipeline features be used as source information for charting without further validation of origin.Numerous charted features exist within the limits of sheet H13191. All assigned features included in the project Composite Source File (CSF) have been addressed by the survey and are included in the FFF. Due to the large scale of the survey (1:5,000), many charted features have been recommended for deletion to be replaced by new higher resolution features digitized from the survey data. The hydrographer frequently requested guidance from HSD staff on appropriate depiction and attribution of features when the procedures set in the HSSD were insufficient to support the requirements of this precision navigation survey. Copies of this correspondence are included in Appendix II. The survey area includes 12 charted features labeled as Position Approximate (PA), and three reported shoals. -The Shoaling reported 2017 PA charted mid river at mile 156.4 AHOP can be updated with surveyed depths. -The Obstruction PA with depth unknown charted on the east bank at mile 147.9 AHOP was disproved by the survey. -The Obstruction PA with depth unknown charted on the east bank at mile 147.7 AHOP was disproved by the survey. -The Lutcher Intake Private Light PA charted on east bank at mile 147.5 AHOP was relocated 27m southeast of the charted location by the survey. -The Obstruction PA with depth unknown charted on the east bank at mile 147.1 AHOP was disproved by the survey. -The Obstruction PA with depth unknown charted on the east bank at mile 147.0 AHOP was disproved by the survey. -The Obstruction PA with depth unknown charted on the east bank at mile 146.5 AHOP was disproved by the survey. -The Obstruction PA with depth unknown charted on the east bank at mile 141.0 AHOP was disproved by the survey. -The Wreck PA with depth unknown charted on the west bank at mile 138.6 AHOP was disproved by the survey. -The Obstruction PA with depth unknown charted mid channel at mile 135.3 AHOP was disproved by the survey. -The Obstruction PA with depth unknown charted on the east bank at mile 135.1 AHOP was disproved by the survey. -The Obstruction PA with depth unknown charted on the east bank at mile 134.9 AHOP was disproved by the survey. -The Obstruction PA with depth unknown charted on the east bank at mile 134.8 AHOP was disproved by the survey. -The Shoaling reported 1983 charted mid river at mile 132.8 AHOP can be updated with surveyed depths. -The Shoaling reported 1983 charted on the west bank at mile 132.0 AHOP can be updated with surveyed depths. All disproved features have been included in the FFF with a description of ‘Delete’. All new features have been included in the FFF depicting the feature as surveyed and with a description of ‘New’. The FFF includes assigned features, both baring and submerged, charted shoreward of the NALL that were too hazardous to survey. The baring features were either beyond the detection range of the MMS or obscured by river traffic, such as moored vessels or barge fleets. Multiple unsuccessful attempts were made to detect these outstanding obscured features. These features are included in the FFF with a description of 'Not Addressed'. There are no pilot boarding areas within the limits of survey H13191. Survey area H13191 contains the Mississippi River, Lower Belmont Crossing Channel. According to the chart, the project depth for the crossing channel is 13.7 meters (45 feet) for a width of 152.4 meters (500 feet). The controlling depths are published in Navigation Bulletins issued periodically by the New Orleans District Corps of Engineers, New Orleans, Louisiana. Crossing channels may be marked by buoys during low water. It is noted this channel is not regularly maintained. The crossing channel uses the project depth 13.7 meters are included in the chart comparison graphics, Figures 21 and 22. There are six range lights associated with the Lower Belmont Crossing Channel outside of the survey limits of H13191. These range lights were not assigned in the CSF, therefore were not included in the FFF for this survey. All six range lights were surveyed in their charted position, although not addressed in this survey. The following anchorages are charted within the H13191 survey limits: Belmont Anchorage, Upper Grand View Reach Anchorage, Middle Grand View Reach Anchorage, Lower Grand View Reach Anchorage, Tigerville Anchorage, and Laplace Anchorage. MBES data acquired within these anchorages were carefully reviewed for features that could pose a risk to anchoring or navigation. New uncharted features were discovered in the Upper Grand View Anchorage and Laplace Anchorage. All surveyed features within designated anchorages are included in the FFF. The Upper Grand View Reach Anchorage, Middle Grand View Reach Anchorage, Lower Grand View Reach Anchorage, Tigerville Anchorage, and Laplace Anchorage do not have object name attributes listed in the ENC. The hydrographer recommends adding the name to the anchorage’s (ACHARE) object name on the ENC. The chart comparison was performed by comparing H13191 survey depths to a digital surface generated from electronic navigational charts (ENCs) covering the survey area. A 10-meter product surface was generated from a triangular irregular network (TIN) created from the ENC’s soundings, depth contours, and depth features. An additional 10-meter HIPS product surface of the entire survey area was generated from the 4-meter CUBE surface. The chart comparison was conducted by creating and reviewing a difference surface using the ENC surface and survey surface as inputs. The chart comparison also included a review of all assigned charted features within the survey area. The results of the comparison are detailed below. Sediment migration and other river environmental conditions contribute to a continually changing river bottom resulting in large differences observed by the field unit daily. The relevant charts used during the comparison were reviewed to check that all US Coast Guard (USCG) Local Notice to Mariners (LNMs) issued during survey acquisition, and impacting the survey area, were applied and addressed by this survey.120002019-04-04102019-04-04US6LA54MOne Danger to Navigation (DtoN) was submitted for this survey on October 17th, 2018. H13191 DtoN01 reported significant shoaling in the vicinity of Belle Point (RM142.4 AHOP) and Willow Bend on the Lower Mississippi River. The non-standard submission included a selected sounding set with an interval of approximately 20m, and chart interval depth curves, both in S-57 format. The DtoN has been registered by the Nautical Data Branch and sent to Products Branch G for processing. The DtoN impacts chart 11370 and ENC US6LA54M and US5LA52M. This nonstandard DtoN has not been included in the H13191 FFF.All uncharted features discovered during survey acquisition are addressed in the FFF. Refer to the FFF for additional information.North American Datum 1983Projected UTM 15During acquisition, RTK correctors were obtained from Louisiana State University’s (LSU) Center for Geoinformatics (C4G) service via a dedicated cellular modem. These correctors provided RTK level of accuracy for horizontal and vertical positions for all survey data. If a loss of service was experienced during acquisition it was noted by the field watch stander, and those data were further analyzed to be resurveyed. No prolonged outages were experienced during survey acquisition of H13191. Verification of the C4G Network correctors were conducted by the field unit at various monuments established by USACE along the shoreline of the OPR-J347-KR-18 project area. Methods, analysis and results of these monument check-ins are further documented in the project wide HVCR. Water level floats were conducted by the field unit at the location of each USACE or NOAA gauge within the OPR-J347-KR-18 project area. Methods, analysis and results of these floats are further documented in the project wide HVCR. In general, these floats helped identify issues between the USACE and NOAA datums and that of the LWRP 2007 separation model utilized during acquisition. These tests resulted in iterations to the model by NOAA, discussed in detail in the HVCR. Water Level FloatsAs discussed in section C4 of the DAPR and the project wide HVCR, due to a revision of the separation model used during acquisition, all ERS water levels were reprocessed after the revised model was issued. Refer to section B4.c of the DAPR for an outline of the processing steps.Separation model change and re-processingLW Reference Plane 2007NAD83-LWRP2007_RM13.4_MLLW2012-2016_Geoid12B.csarWhile ERS via VDATUM is listed in Table 13, it was one of the limited options available in the XML DR schema’s enumerated values. The separation model covering the H13191 survey area was constructed by the HSD Operations Branch specifically for this survey project using NAVD88 (GEOID 2012B) to Mississippi River Low Water Reference Plane of 2007 (LWRP 2007) values published by USACE. Refer to the HVCR submitted under separate cover for additional information.ERS via VDATUMA complete description of the horizontal and vertical control for survey H13191 can be found in the OPR-J347-KR-18 Horizontal and Vertical Control Report (HVCR), to be submitted with the final survey for this project. A summary of horizontal and vertical control for this survey follows.Data Acquisition and Processing Report2019-09-20Coast Pilot Report2019-07-112019-11-18Jonathan L. Dasler, PE, PLS, CHNSPS/THSOA Certified Hydrographer, Chief of Party2019-11-18Jason Creech, CHNSPS/THSOA Certified Hydrographer, Charting Manager / Project Manager2019-11-18Callan McGriff, EITIHO Cat-A Hydrographer, Lead Hydrographer2019-11-18David T. Moehl, PLS, CHNSPS/THSOA Certified Hydrographer, Lead HydrographerAs 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, with the exception of the deficiencies outlined in this report. 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, and Letter Instructions. These data are adequate to supersede charted data in their common areas. This survey is complete and no additional work is required.Multibeam backscatter was logged in Hypack 7k format and included with the H13191 digital deliverables. Data were processed periodically in CARIS HIPS to evaluate backscatter quality, but the processed data is not included with the deliverables. For dual-head MBES data on S/V Blake, individual 7k files were logged for each sonar head in order to better facilitate additional changes required between systems. For data management purposes, the names of multibeam crosslines have been appended with the suffix _XL. This change was made to HIPS files only. The original file names of raw data files (Hypack HSX and 7k) have been retained.The sounding density requirement of 95% of all nodes, populated with at least five soundings per node, was verified by analyzing the density layer of each finalized surface. Individual surface results are stated in Figures 17 through 19.DensitySupportFiles\H13191_MB_50cm_LWRP_Final.QAv5.density.pngNode density statistics - 50cm finalized SupportFiles\H13191_MB_1m_LWRP_Final.QAv5.density.pngNode density statistics - 1m finalized SupportFiles\H13191_MB_4m_LWRP_Final.QAv5.density.pngNode density statistics - 4m finalized Occasional data gaps in the final Object Detection surfaces exist due to operational restrictions at time of survey. These data gaps were further analyzed after acquisition and determined to be unattainable due to safety or other factors impacting vessel operations. Significant effort was expended during survey operations to maximize object detection coverage in these areas. Some of the sources for these data gaps include: - Holidays or 2-meter coverage gaps behind pier structures where field unit was physically unable to operate, or safety concerns limited their ability. - Holidays beyond the 2-meter curve (NALL) which were not further investigated due to safety concerns in shallow water. - Holidays or 2-meter coverage gaps underneath barge fleets or anchored/moored vessels. These were revisited at least one other time in subsequent days. Typically, the field hydrographer would acquire data along the achievable extents of the gap, and document the existence of the barge fleet or vessel with targets and/or photos. AIS or internet-based vessel tracking tools were used to alert the field unit when vessels were underway. - Holidays created beneath baring structures that met the area requirements were rejected in the survey data for final delivery. Holidays that exist in the final surfaces have been noted in the H13191_Notes_for_Reviewer.hob with the cvrage area feature class, submitted in Appendix II, and attributed with remarks stating the contributing factor leading to the data gap. Areas were the 2-meter curve was not met are included in the H13191_Notes_for_Reviewer.hob with SLCONS feature class and attributed with remarks stating the contributing factor for this deficiency.Data gaps in bathymetric coverage 5000David Evans & Associates, Inc.2018SH13190At the time of writing, data from survey H13190 was still being processed. The Descriptive Report for H13190 will include the junction analysis with H13191. 5000David Evans & Associates, Inc.2018NH13192Survey H13192 is also part of the OPR-J347-KR-18 survey project. The mean difference between H13191 and H13192 survey depths is 3 centimeters (H13191 deeper than H13192), shown in Figure 11. Major differences are representative of surveys impacted by sediment migration, visible in the middle of the channel in this stretch of river. Figure 12, represented in meters, shows the area of overlap with grey shades showing general agreement. Warmer colors represent H13191 survey depths shoaler than H13192, while cooler colors indicate H13191 survey depths deeper than H13192.SupportFiles\H13191_MB_1m_LWRP_to_H13192_MB_1m_LWRP_depth_delta.pngDistribution summary plot of survey H13191 1-meter vs H13192 1-meter SupportFiles\H13191_Junction_vs_H13192.pngJunction difference surface between surveys H13191 1-meter and H13192 1-meterSurvey H13191 junctions with current surveys H13192 and H13190. No prior surveys were specified as junctions in the Project Instructions. High frequency artifacts are visible periodically in the data collected with the dual-head system on the S/V Blake. Despite extensive testing and troubleshooting of mount stability under a range of vessel motion dynamics and speed, applied offsets, and application of patch tests bias, no single source of the artifact could be identified. The high frequency artifact was transient and unrelated to vessel dynamics and loading on sonar mounts at different speeds and induced rolling during testing and is periodically present in both sonars, with a higher magnitude observed on the port sonar. From the findings of the troubleshooting, it is the hydrographer's belief that this is not related to mount instability relative to the IMU of patch test bias values applied and may be related to minor transient timing issues in the dual head system relative to the application of motion data (primarily role). Under this assumption, the further away the sensor is from the ship reference point, the great the magnitude of the error. In this case, while the artifact negatively affects the aesthetic of the final surface deliverable, it is well within IHO specifications for this survey. Figures 13 and 14 display the artifact for the dual-head operations.High Frequency artifact in dual-head MBES systemSupportFiles\OPR-J347-KR-18_artifact_port_sonar.pngExample of high frequency artifact shown in surface and along track subset. Subsets of differing magnitudes between separate sonar heads of dual-head system shown on port side of swath (starboard beams shown in red, port beams in green)SupportFiles\OPR-J347-KR-18_artifact_stbd_sonar.pngExample of high frequency artifact shown in surface and along track subset. Subsets of differing magnitudes between separate sonar heads of dual-head system shown on starboard side of swath (starboard beams shown in red, port beams in green)Delayed heave was applied to data collected by the S/V Blake using the POS M/V .000 file logged during acquisition. This file is loaded using the CARIS Import Auxiliary Data tool. Delayed heave is chosen during the SVC and Merge processing steps. Prior to October 18, 2018 (DN291) delayed heave for the RHIB Sigsbee was obtained by using the post-processed Hydrins 'smart heave' solution. The data was exported to a custom *.txt file and applied to the delayed heave HDCS using CARIS Generic Data Parser (GDP) utility. Post October 18, 2019, delayed heave was applied to data collected by the RHIB Sigsbee using the IXSEA Output_E.log file logged during acquisition. This file is formatted similarly to the POS M/V .000 file for delayed heave, but does not contain any position, motion, or associated RMS values. The Output_E.log file was loaded using the CARIS Import Auxiliary Data tool and applied during the SVC and Merge processing steps. Delayed HeaveFill data collected after 17:42 on September 10, 2019 (DN253) is corrected using an exact one-second latency value entered in the HIPS Vessel File (HVF). This was due to a malfunction of the dual-head MBES system, resulting in a systematic restart which caused timing to be reestablished an exact second off actual time. This value was confirmed using HIPS calibration tool and comparing positions of features to prior data collected. One-second Timing Correction for MBES DataSurvey speeds were typically maintained to meet or exceed along-track density requirements. However, due to swift current pushing the vessel downriver and the need to maintain maneuverability, combined with deep areas requiring expansion of the sonar range and thereby slowing the sonar ping rate, along-track low-density areas are occasionally present in the final data. These typically are narrow swaths centered along nadir and do not impact meeting density requirements for 95% of all nodes. Mobile lidar coverage was obtained on the full extents of both river banks spanning the survey area.Quality control is discussed in detail in Section B of the DAPR. Results from weekly position checks and weekly multibeam bar checks are included in Separate I Acquisition and Processing Logs of this report. Sound speed checks can be found in Separate II Sound Speed Data Summary of this report. Multibeam data were reviewed at multiple levels of data processing including: CARIS HIPS conversion, subset editing, and analysis of anomalies revealed in CUBE surfaces.0.0300.084ERS via VDATUM1.00.5S/V Blake1.00.5RHIB Sigsbee1.0Additional discussion of these parameters is included in the DAPR. Sound speed profiles collected from the RHIB Sigsbee were acquired with AML BaseX or AML SmartX sound speed sensors. The S/V Blake used an AML BaseX to acquire sound speed measurements on September 10, 2019 (DN253). The measurement uncertainty for these sensors is listed in the CTD column in Table 8. During surface finalization in HIPS, the "Greater of the two values" option was selected, where the calculated uncertainty from Total Propagated Uncertainty (TPU) is compared to the standard deviation of the soundings influencing the node, and where the greater value is assigned as the final uncertainty of the node. The uncertainty of the finalized surfaces increased for nodes, where the standard deviation of the node was greater than the TPU. To determine if the surface grid nodes met IHO Order 1 specification, a ratio of the final node uncertainty to the allowable uncertainty at that depth was determined. As a percentage, this value represents the amount of error budget utilized by the total vertical uncertainty (TVU) at each node. Values greater than 100% indicate nodes exceeding the allowable IHO uncertainty. The resulting calculated TVU values of all nodes in the submitted finalized surfaces are shown in Figures 8 through 10. The finalized surfaces include occasional large vertical uncertainties which exceed IHO Order 1 allowances. These high uncertainties were caused by introducing areas of high depth standard deviation associated with steep slopes when finalizing surfaces with the greater of the two option; and incorporating erroneous real-time sonar uncertainty values during TPU computation. On occasion, the real-time uncertainty logged during acquisition included a sounding with an extremely high depth uncertainty which was well outside of realistic values. During processing, an IHO filter was applied to all sounding data, with rejecting soundings exceeding IHO Order 1 thresholds for TVU. These rejected soundings have at times been reaccepted after thorough review by the hydrographer. This issue appears to have been caused by an unresolved software bug in either the sonar top side unit or acquisition system impacting the reported uncertainty, but not the actual depth.SupportFiles\H13191_MB_50cm_LWRP_Final.QAv5.tvu_qc.pngNode TVU statistics - 50cm finalized SupportFiles\H13191_MB_1m_LWRP_Final.QAv5.tvu_qc.pngNode TVU statistics - 1m finalized SupportFiles\H13191_MB_4m_LWRP_Final.QAv5.tvu_qc.pngNode TVU statistics - 4m finalized Approximately four-hour intervalsAn AML Oceanographic Moving Vessel Profiler (MVP) and an AML SmartX or BaseX were the primary instruments used to acquire sound speed readings during multibeam operations for the S/V Blake and the RHIB Sigsbee, respectively. Additional discussion of sound speed methods can be found in the DAPR. For H13191 survey operations, sound speed was well mixed and varied negligibly, both temporally and spatially. Due to the consistent sound speed profile encountered in this reach of the river, sound speed profiles were measured at approximately one to two-hour intervals during survey operations. Sound speed readings were applied in CARIS at a four-hour interval based on consistent profiles observed throughout the day of survey. All sound speed measurements were made within 250 meters of the planned survey boundary. During H13191 survey operations, the S/V Blake and RHIB Sigsbee did not consistently acquire a sound speed profile before starting acquisition each survey day. For most days, the time differential varied between start of acquisition and the first cast of the day. A sound speed profile was acquired prior to acquisition during RHIB Sigsbee operations on DN285, DN287, DN298, and DN299. As the Mississippi River is well mixed in this reach, there was no temporal or spatial variation in sound speed during acquisition in this reach off the river and sounding data were not impacted. Taking sound speed casts prior to and after acquisition was corrected as the survey operations progressed downstream.Multibeam crosslines were run across the entire survey area to provide a varied spatial and temporal distribution for analysis of internal consistency within the survey data. Crossline analysis was performed using the CARIS Hydrographic Information Processing System (HIPS) Quality Control (QC) Report tool, which compares crossline data to a gridded surface and reports results by beam number. Crosslines were compared to a 1-meter CUBE surface encompassing mainscheme, fill, and investigation data for the entire survey area. The QC Report tabular output and plots for both survey vessels are included in Separate II Checkpoint Summary and Crossline Comparison. For the S/V Blake the output and plot contain data from a dual-head system, beams 1 to 256 are from the starboard head while 257 to 512 are from the port head. Due to significant sediment migration occurring within the survey, crosslines were generally conducted on the same day as mainscheme acquisition in order to reduce the impact of the changing riverbed on crossline agreement. This resulted in a time differential of under eight hours between mainscheme and crossline acquisition and significant change in the riverbed was still apparent. Tests run prior to the 2019 flooding event showed sediment wave movement at a rate of 0.25 meters per hour with even higher rates observed during flooding. Even with these operational adjustments, crossline statistics from the S/V Blake, which operated in deeper water over the main channel, exceed International Hydrographic Organization (IHO) Order 1 specification as reported by the CARIS HIPS QC Report tool. DEA performed an additional crossline analysis using the NOAA Pydro Compare Grids tool to analyze the differences between gridded mainscheme depths and gridded crossline depths. Input grids were 1-meter resolution CUBE surfaces of mainscheme and crossline depths. Results from the crossline to mainscheme difference analysis are depicted in Figures 6 and 7, units are represented in meters. Figure 7 depicts a difference surface portraying the sediment migration seen throughout the duration of survey. This figure details crosslines conducted at the end of a survey day, approximately six hours after the first mainscheme line was acquired for the day of acquisition. Change is significant in the sediment wave field with horizontal migration of up to 3 meters occurring between mainscheme and crossline acquisition. The shape of the waves is apparent in both the crossline/mainscheme difference image and multibeam hillshade. In the crossline difference image, overlaid on the final multibeam hillshade, shades of yellow and red indicate shoaling in meters and shades of blue indicate deepening in meters with both following the form of the wave field as sediment waves migrate. Shades of grey indicate areas that meet requirements and are generally outside the sediment wave field where there has been less change. DEA remains confident that data consistency was maintained during acquisition based on swath to swath comparison of two vessel platforms and three sonars operating simultaneously in the same survey area. DEA confirmed that a systematic error, such as positioning or sound speed measurements, was not a factor leading to these large differences based on weekly system comparisons detailed in Separate I Acquisition and Processing Logs of this report. To further document the system performance, an additional crossline report was run on data acquired in the vicinity of Gulfport Channel, near the project’s mobilization grounds and outside of the influence of sediment migration. The output of this report confirms the S/V Blake’s sonar and acquisition and processing procedures are capable of acquiring data that exceeds IHO specification for Order 1 and Special Order as reported by the HIPS QC Report tool. Output from the report is included in Separate II Checkpoint Summary and Crossline Comparison. This issue was not limited to this survey area; sediment migration affected the entire OPR-J347-KR-18 project area. Impacts of sediment migration are further discussed in section B.2.6 of this report.SupportFiles\H13191_XL_1m-H13191_MS_1m_depth_delta.pngH13191 Crossline Difference Distribution Summary PlotSupportFiles\H13191_Crossline_Difference_Surface.pngH13191 crossline difference surface overlayed on the multibeam hillshade highlighting sediment migrationSediment migration on the river bottom was evident throughout the course of this survey. Crosslines and fill lines that were run hours after mainscheme acquisition still exceeded the allowable vertical uncertainty in some areas. Following guidance from HSD OPS and the Atlantic Hydrographic Branch, the hydrographer allowed the CUBE algorithm to estimate a gridded depth in these areas without manual cleaning of the sounding data. The submitted surface has numerous artifacts resulting from these areas of disagreement. When reviewed, soundings deemed as fliers were still rejected. It is the hydrographer's belief that the submitted depths were accurate at the time of the survey. Figure 15 shows an example of horizontal movement (approximately 5 meters) in sediment waves that resulted in disagreement for H13191 submitted surfaces. Some areas of the greatest disagreement have been noted in the H13191_Notes_for_Reviewer.hob file with the SNDWAV area feature class, submitted in Appendix II of this report. This is not an exhaustive list of areas but should detail those that show the major surface artifacts resulting from sediment migration. In the vicinity of Baton Rouge, while in an area of significant sediment migration but prior to flood levels, a field test was conducted to attempt to quantify the amount of change the river bottom experienced at that time of survey. The same line was run upstream at similar speeds with time elapsing between subsequent passes. A subset of the results is shown in Figure 16. A high vertical exaggeration is used in Figure 16 to highlight the magnitude of the sediment migration. The hydrographer's best estimate is that the smaller waves on top are migrating at nearly 1 meter per hour while the larger waves, nearly 2 meters high, are migrating at 5 meters per day.Sediment MigrationSupportFiles\H13191_Sediment_Migration.pngExample of artifacts caused by sediment migration during H13191 operationsSupportFiles\OPR-J347-KR-18_Sediment_Migration.pngAlong-track subset view of field test portraying river bottom changes due to sediment migrationMBESSeaBat T50-RTeledyne RESONMBESSeaBat T50-PTeledyne RESONLidar SystemVUX-1HARIEGLLidar SystemLMS-Z390iRIEGLPositioning and Attitude SystemPOS MV 320 v5ApplanixPositioning and Attitude SystemPOS LV 620ApplanixPositioning and Attitude SystemHydrinsiXbluePositioning SystemSPS851TrimblePositioning SystemSPS855TrimblePositioning SystemRTK Bridge-XIntuicomSound Speed SystemMVP30-350AML OceanographicSound Speed SystemSmartXAML OceanographicSound Speed SystemBaseXAML OceanographicSound Speed SystemMicroX SVAML OceanographicConductivity, Temperature, and Depth SensorSBE 19plusSea-Bird ScientificSupportFiles\OPR-J347-KR-18_Blake.pngS/V BlakeSupportFiles\OPR-J347-KR-18_Sigsbee.pngRHIB Sigsbee834.5S/V Blake181.0RHIB SigsbeeThe OPR-J347-KR-18 Data Acquisition and Processing Report (DAPR), previously submitted with survey H13195, details equipment and vessel information as well as data acquisition and processing procedures. There were no vessel or equipment configurations used during data acquisition that deviated from those described in the DAPR except for sonar settings used during acquisition of some fill and investigation data. For fill and investigation lines conducted on September 10, 2019 (DN253), the dual-head multibeam system was operated in equi-angular (EA) mode, rather than equi-distant (ED) as described in the DAPR. 10.4.5HIPS/SIPSCARISNOAA Profile Version 5.7A detailed listing of all data processing software, including software used to process the mobile lidar data, is included in the DAPR.Bathymetric grids were created relative to LWRP in CUBE format using Object Detection resolution requirements as described in the HSSD.0.5NOAA_0.5mH13191_MB_50cm_LWRP55.161-2.331CARIS Raster Surface (CUBE)Object Detection1NOAA_1mH13191_MB_1m_LWRP54.998-2.316CARIS Raster Surface (CUBE)Object Detection4NOAA_4mH13191_MB_4m_LWRP54.909-2.253CARIS Raster Surface (CUBE)Object Detection0.5NOAA_0.5mH13191_MB_50cm_LWRP_Final20.000-2.331CARIS Raster Surface (CUBE)Object Detection1NOAA_1mH13191_MB_1m_LWRP_Final40.00018.000CARIS Raster Surface (CUBE)Object Detection4NOAA_4mH13191_MB_4m_LWRP_Final54.90936.000CARIS Raster Surface (CUBE)Object DetectionFill and investigation data were collected by the S/V Blake on September 10, 2019 (DN253). Due to historic flooding restricting access to these areas, there was approximately a ten-month stand down on survey operations after mainscheme acquisition. Areas of large disagreement exist in these data where the river bottom has greatly changed since the prior mainscheme collection. HSD staff provided guidance on how to address data that impacted the surface deliverables negatively for data acquired on DN253. To limit the effect on the surface, soundings collected on this fill and investigation day of survey that were in disagreement with previous acquisition have been rejected in subset editor. Investigation lines with soundings on a feature that remained intact over time were generally accepted, and the surrounding soundings on the seafloor that caused disagreement were rejected. Figure 20 illustrates an example of large disagreement of 2 meters between mainscheme acquisition and a fill line, 2019BL2531835. The following details how specific fill lines were processed. Lines with all soundings completely rejected in subset editor: 2019BL2531658 (fill line, no feature present in holiday) 2019BL2531711 2019BL2531802 Line 2019BL2531835 was partially rejected in areas of large disagreement. All other lines collected on this day generally agree with the prior survey lines and were processed as discussed in the DAPR.Rejection of Fill and Investigation Data in Areas of DisagreementSupportFiles\H13191_DN253_Fill_Disagreement_Example.pngExample of large disagreement from rejected line 2019BL2531835A total of 134 soundings in H13191 were designated in bathymetric data: 133 soundings to facilitate feature management for inclusion in the H13191 Final Feature File (FFF). There is one sounding that was identified to override the gridded surface model. Designated SoundingsDuring processing of S/V Blake HDCS lines, navigation information was imported from POS M/V .000 files while importing delayed heave, motion and associated RMS values. This navigation source, Applanix.ApplanixGroup1, is automatically applied at merge when it exists. However, when a CARIS project file is rebuilt, CARIS will report that the navigation source is the HDCSNav. This is a display issue only and does not change the navigation source. This is not an issue for data collected by the RHIB Sigsbee, which relies on HDCS navigation, and does not apply logged navigation, motion and RMS. Additionally, when a line is renamed, such as with the suffix _XL, the HDCSNav source disappears from the metadata display. Again, this appears to be a display issue only and does not change any navigation sources.CARIS HDCS Navigation SourcesA vessel-based MMS was used to acquire lidar and imagery data along the survey area’s shoreline in order to facilitate the survey, management, and reporting of shoreline and nearshore features. Processed LAS data from the laser scanner are included with the survey deliverables in the Processed directory. Imagery data collected by the MMS were used for feature interpretation during processing. Photos of individual features were extracted from the imagery data or taken during hydrographic survey operations and included with the images attribute in the FFF. If vessels at berth limited lidar data collection during initial MMS acquisition in high priority areas assigned in the Project Instructions, data were attempted to be reacquired using the secondary laser scanner during MBES survey operations. Further, supplemental photographs were taken of some features where the MMS imagery was not sufficient to accurately depict the feature.Mobile Laser Scanner DataA patch test was conducted for the S/V Blake on September 5, 2019 (DN248) before recommencing acquisition on OPR-J347-KR-18. This patch test was not finalized by the office before submittal of the DAPR on September 20, 2019 and is included in the HVF submitted with this survey.Patch TestRemobilization of OPR-J347-KR-18 fieldwork2019-09-05All data reduction procedures conform to those detailed in the DAPR.SupportFiles\H13191_SurveyOutline.pngH13191 Survey OutlineSupportFiles\H13191 - laser scan areas.pngH13191 Assigned Mobile Mapping AreasThe river bottom is continuously changing due to currents, vessel propeller wash, dredging activity, construction and/or other factors present in the river environment. Changes in the river bed were observed during acquisition, primarily due to sediment migration. Section B.2.6 of this report further discusses these issues and impacts to the final deliverable data. In all cases the hydrographer has verified that soundings accurately depicted the river bed at the time of acquisition.The entire survey is adequate to supersede previous data.The Ports of Southern Mississippi River represent the largest port complex in the world and one of the most heavily trafficked waterways in the United States. Annually, over 500 million tons of cargo is moved on the Lower Mississippi. This project area includes the Port of South Louisiana, the Port of New Orleans, the Port of Greater Baton Rouge, and Plaquemines Port, all ranking in the top 12 ports for annual tonnage in the United States. The Port of South Louisiana, river mile 114.9 to 168.5, is the largest tonnage port in the western hemisphere, handling approximately 262 million tons. The Port of New Orleans, river mile 81.2 to 114.9, handles approximately 90 million tons annually. The Port of Greater Baton Rouge, river mile 168.5 to 253, and Plaquemines Port, river mile 0 to 81.2, handle approximately 73 and 57 million tons annually, respectively.* Critical Charting updates are needed for the Mississippi River, especially for areas outside of the U.S. Army Corps of Engineers (USACE) federally maintained channel areas. These areas outside of the federally maintained channel account for the majority of the navigable river and include ports and terminals essential for commerce and trade. The new bathymetric data in this project area, encompassing 89 SNM, will support high resolution charting products for maritime commerce and update National Ocean Service (NOS) nautical charting products. * U.S. Army Corps of Engineers, Navigation Data Center, Waterborne Commerce Statistics Center, Principal Ports of the United States, www.navigationdatacenter.us/data/datappor.htmSurvey Limits were surveyed in accordance with the requirements in the Project Instructions and the HSSD. For this document, cardinal directions are generalized to river flow due to the winding nature of the Mississippi River. North is used for upriver and south is used for downriver. When facing downriver, the left bank is referenced as east, and the right bank is referenced as west. SupportFiles\OPR-J347-KR-18_Survey_Outline.pngOPR-J347-KR-18 Survey Areas9.1500002018-08-122018-08-142018-08-172018-10-102018-10-112018-10-122018-10-132018-10-142018-10-162018-10-172018-10-192018-10-202018-10-212018-10-252018-10-262018-11-052019-09-1000500.36000022.324.4654.5200276.24000019.5054.52S/V Blake00224.1100002.820.00RHIB Sigsbee29.977933590.468961805630.055235590.8276826944David Evans and Associates, Inc. (DEA) conducted a hydrographic survey of the assigned area in the Mississippi River. Survey H13191 was conducted in accordance with the November 19, 2018 Statement of Work and Hydrographic Survey Project Instructions dated August 8, 2019. The Hydrographic Survey Project Instructions reference the National Ocean Service (NOS) Hydrographic Surveys Specifications and Deliverables Manual (HSSD) (March, 2018) as the technical requirements for this project.All waters in survey areaObject Detection Coverage (HSSD Section 5.2.2.2) Project Instructions called for high resolution charting at 1:5,000 survey scale to support NOAA’s Precision Navigation initiative for the Mississippi River including: Object Detection Coverage for all waters in the survey area to the 2-meter depth contour; Ellipsoid Reference Survey (ERS) using a custom separation model for the Mississippi River; verification of ATONs; assignment of shoreline and nearshore features (including bridges, overhead wires, revetments, assigned existing terminals, and all uncharted features) to be obtained by a vessel based mobile laser scanning technology and imaging system, or Mobile Mapping System (MMS); and delivery of LAS data referenced using ERS methods. Operational challenges included, but were not limited to: conducting surveys in a heavily congested industrial waterway; high river current velocities and transiting debris from high water levels; over 465 miles of shoreline surveys in restricted waters with small launch operations in close proximity to terminals, large barge fleets, wrecks, ruins, submerged piling, and numerous snags; minimal river access for provisioning and refueling; dynamic sediment migration exceeding 0.25 meters per hour in some areas; resolution of chart datum and revisions to the separation model; coordinating mapping efforts with ships at berth; dense fog; on-going dredging operations; and various navigational trials associated with a heavily trafficked industrial waterway. To mitigate these challenges and with the volume of shoreline operations required, survey operations were conducted during daylight hours only, AIS and internet vessel tracking systems were utilized, and continuous communications were made to terminal operators and vessel captains by radio and phone. Object detection coverage was obtained over the survey area in depths greater than 2 meters relative to chart datum using 100% multibeam echosounder (MBES) and backscatter unless otherwise discussed in individual sections of this report. This coverage type follows Option A of the Object Detection Coverage requirement specified in Section 5.2.2 of the 2018 HSSD. Historic flooding of the Mississippi River during OPR-J347-KR-18 survey impacted safe operations in high currents and restricted operations. Many features were in locations that restricted a 90-degree pass due to strong currents and proximity to shoreline, fixed structures or barge fleeting. Further, flooding and strong river currents resulted in significant sediment migration during and between survey operations, evident on this survey sheet. Unavoidable coverage gaps are evident in some areas and are primarily due to large barge fleeting areas. Other factors that blocked or impeded safe vessel operations resulting in data gaps included: berthed vessels that remained during survey operations; low wires behind structures; mooring lines; in-water facilities, ruins, and overgrown vegetation along shoreline. Significant efforts were expended to maximize coverage to the extent possible in these areas. Section B.2.10 of this report discusses issues restricting this survey coverage in greater detail. Figure 2 depicts the survey outline that was obtained for H13191. The Project Instructions required the use of the MMS for scanning of bridges, overhead cables, and terminal facilities located in the survey area. These areas, which are depicted in Figure 3, were identified in the Project Reference File (PRF) as Anchorage area feature types (ACHARE). Overhead clearances of the assigned bridges and cables, discussed in D.2.3 Overhead Features, were computed from LAS data. MMS acquisition was expanded outside of these assigned areas to encompass the entire survey area in order to facilitate the survey, management, and reporting of all shoreline and nearshore features located within the project area. Contractor5000LouisianaH13191United States4Mississippi River, Vicinity of Mile 156.5 to 130OPR-J347-KR-18David Evans and AssociatesMississippi RiverMississippi River2019-08-08Navigable AreaUTCPacific Hydrographic Branch2018Jonathan L. Dasler, PE, PLS, CHMultibeam Echo Sounder BackscatterMultibeam Echo Sounder2019-09-102018-08-12The 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/.meters