NOS HYDROGRAPHIC SURVEYS SPECIFICATIONS AND DELIVERABLES April 2009 U.S. Department of Commerce National Oceanic and Atmospheric Administration Contents 1 Introduction 1 1.1 Definition . 1 1.2 Changes from April 2008 . 1 2 Datums 3 2.1 Horizontal Datum . 3 2.2 Sounding Datum . 3 2.3 Time . 3 3 Hydrographic Position Control 4 3.1 Horizontal Position Accuracy . 4 3.2 Differential Global Positioning System . 4 3.2.1 DGPS Specifications . 4 3.2.2 DGPS Site Confirmation . 5 3.2.3 Other GPS Techniques . 5 4 Tides and Water Levels Requirements 6 4.1 General Project Requirements and Scope . 6 4.1.1 Scope . 6 4.1.2 Objectives . 6 4.1.3 Planning and Preliminary Tidal Zoning . 7 4.1.4 NOS Control Stations and Data Quality Monitoring . 7 4.1.5 General Data and Reference Datum Requirements . 8 4.1.6 Error Budget Considerations . 8 4.2 Data Collection and Field Work . 9 4.2.1 Water Level Station Requirements . 9 4.2.2 Water Level Measurement Systems and Data Transmissions . 10 4.2.3 Station Installation, Operation and Removal . 12 4.2.4 Tide Staffs . 14 4.2.5 Bench Marks and Leveling . 19 4.2.6 Water level Station Documentation . 20 4.2.7 Additional Field Requirements . 20 4.2.8 Geodetic Connections and Datums Relationship . 21 4.2.9 NAVD 88 Level Tie . 21 4.2.10GPS Observations . 22 4.2.11North American Datum (NAD 83) GPS Tie . 25 4.2.12GPS Data Processing Using OPUS . 26 4.2.13OPUS DB Preliminary Information . 27 4.2.14NAVD 88 GPS Tie . 29 4.3 Data Processing and Reduction . 29 4.3.1 Data Quality Control . 29 4.3.2 Data Processing and Tabulation of the Tide . 29 4.3.3 Computation of Monthly Means . 30 4.3.4 Data Editing and Gap Filling Specifications . 30 4.4 Computation of Tidal Datums and Water Level Datums . 34 4.4.1 National Tidal Datum Epoch . 34 4.4.2 Computational Procedures . 34 4.4.3 Tidal Datum Recovery . 34 4.4.4 Quality Control . 50 4.5 Final Zoning and Tide Reducers . 50 4.5.1 Water Level Station Summaries . 50 4.5.2 Construction of Final Tidal Zoning Schemes . 51 4.5.3 Tide Reducer Files and Final Tide Note . 51 4.6 Data Submission Requirements . 57 4.6.1 Station Documentation . 57 4.6.2 GPS Project Documentation . 58 4.6.3 Water Level Data . 73 4.6.4 Tabulations and Tidal Datums . 76 4.6.5 Tide Reducers and Final Zoning and Final Tide Note . 82 4.6.6 Submission and Deliverables – Documentation and Time lines . 82 4.7 Guidelines and References . 85 5 Depth Sounding 87 5.1 Multibeam and Other Echosounders . 87 5.1.1 Accuracy and Resolution Standards . 87 5.1.1.1 Accuracy Standards . 87 5.1.1.2 Multibeam Resolution Standards . 88 5.1.1.3 Gridded Data Specifications . 88 5.1.2 Coverage . 90 5.1.2.1 Object Detection Coverage . 90 5.1.2.2 Complete Multibeam Coverage . 91 5.1.2.3 Set Line Spacing . 92 5.1.3 Corrections to Echo Soundings . 92 5.1.3.1 Instrument Error Corrections . 93 5.1.3.2 Draft Corrections . 94 5.1.3.3 Speed of Sound Corrections . 95 5.1.3.4 Attitude Corrections . 97 5.1.3.5 Error Budget Analysis for Depths . 97 5.1.3.6 Uncertainty Budget Analysis for Depths . 99 5.1.4 Quality Control . 100 5.1.4.1 Multibeam Sonar Calibration . 100 5.1.4.2 Positioning System Confidence Checks . 101 5.1.4.3 Crosslines . 101 5.2 Lidar . 102 5.2.1 Accuracy and Resolution Standards . 102 5.2.1.1 Lidar Resolution Standards . 102 5.2.1.2 Gridded Data Specifications . 103 5.2.2 Coverage . 103 5.2.3 Corrections to Lidar Soundings . 104 5.2.3.1 Instrument Error Corrections . 105 5.2.4 Quality Control . 105 5.2.4.1 Lidar Calibration . 105 5.2.4.2 Positioning System Confidence Checks . 105 5.2.4.3 Crosslines . 106 6 Towed Side Scan Sonar 107 6.1 Coverage . 107 6.2 Side Scan Acquisition Parameters and Requirements . 107 6.2.1 Accuracy . 107 6.2.2 Speed . 108 6.2.3 Towfish Height . 108 6.2.4 Horizontal Range . 108 6.3 Quality Control . 108 6.3.1 Confidence Checks . 108 6.3.2 Significant Contacts . 109 6.3.3 Contact Correlation . 109 6.3.4 Identification of Potential Field Examinations . 109 7 Other Data 110 7.1 Bottom Characteristics . 110 7.2 Aids to Navigation . 110 8 Deliverables 111 8.1 Field Reports . 111 8.1.1 Progress Sketch and Survey Outline . 111 8.1.2 Danger to Navigation . 111 8.1.2.1 Charted Feature Removal Request . 113 8.1.3 Descriptive Report (DR) . 114 8.1.4 Descriptive Report Supplemental Reports . 123 8.1.4.1 Data Acquisition and Processing Report . 123 8.1.4.2 Horizontal and Vertical Control Report . 125 8.2 S-57 Feature File . 126 8.2.1 S-57 Attribution . 127 8.2.2 Cartographic Specifications and Conventions . 132 8.3 Side Scan Sonar . 134 8.3.1 Side Scan Sonar Mosaic . 134 8.3.2 Side Scan Sonar Contact List . 134 8.3.3 Data Acquisition and Processing Abstracts . 136 8.4 Digital Data Files . 138 8.4.1 Media . 138 8.4.2 Single-beam Data . ..