[ { "id": "atiu", "island": "Atiu", "href": "tidal-datums/atiu/", "status": "applied", "display_date": "2026-05-25", "figure_title": "Atiu Tide-Gauge Datum", "figure_path": "static/img/tide-gauge-datums/atiu-datum.svg", "figure_alt": "Atiu datum connection from HISEAS GPS control height, gauge offset, and pressure-derived mean water depth.", "plot_path": "static/img/tide-gauge-datums/atiu-plot.svg", "report_plot_path": "static/img/tide-gauge-datums/atiu-report-plot.svg", "report_record_days": 4, "plot_alt": "Atiu tide-gauge water-depth logger record with local 6, 12, 18, and 24 hour markers.", "caption": "Atiu: zero-corrected clipped mean water depth above logger 1.848 m and mean sea-level datum 14.231 m from the HISEAS GPS altitude reference.", "quality_note": "", "field_comment": "Field notes record repeat dock-to-gauge measurements of 3.32 m and 3.315 m at the harbor concrete tie.", "datum_method": "dock_gps_minus_field_offset_plus_pressure_depth", "mean_sea_level_datum": "14.231 m", "mean_sea_level_datum_pole_removed": "12.012 m", "receiver_phase_center_offset": "2.2187 m", "receiver_pole_spike_height": "2.180 m", "receiver_mounting_bracket_height": "0.003 m", "receiver_arrow_gold_phase_center": "0.0357 m", "datum_reference_frame": "ITRF2008", "mean_clipped_water_depth": "1.848 m", "uncertainty": "-0.412 / +0.426 m", "uncertainty_note": "5-95% tide-depth window: 1.436 m to 2.274 m above logger.", "gauge_offset": "3.317 m", "mean_control_altitude": "15.701 m", "mean_gauge_altitude": "12.384 m", "logger_relative_height": "-1.848 m", "deployment_time_local": "2026-05-25 16:59 CKT", "window_end_time_local": "2026-05-29 07:52 CKT", "control_point_ids": [ "ATIU-20260525-HISEAS-017", "ATIU-20260525-HISEAS-018" ], "gauge_location": { "id": "atiu-tide-gauge", "label": "Atiu harbor tide gauge", "short_label": "Tide gauge", "island": "Atiu", "longitude": -158.139624869, "latitude": -19.978886517, "control_point_ids": [ "ATIU-20260525-HISEAS-017", "ATIU-20260525-HISEAS-018" ] }, "evidence_points": [ { "id": "ATIU-20260525-HISEAS-017", "category": "control", "category_label": "Gauge GPS tie", "label": "Tide gauge", "site_label": "ATIU-20260525-HISEAS-017", "note": "3.317 m field offset to logger. Dock above tide gauge. Reminder: Pole height is set to 0m. Must add pole height to measurement.", "date_label": "2026-05-25 17:16", "height_above_msl": "+1.456 m", "height_above_msl_m": 1.45551, "vertical_accuracy": "0.106 m", "vertical_accuracy_m": 0.105845, "envelope_lower_m": 1.24382, "envelope_upper_m": 1.6672, "envelope_label": "+1.244 m to +1.667 m", "precision": "0.016 m", "offset_position": "", "is_below": false, "logger_offset_label": "3.317 m field offset to logger", "logger_tie_m": -1.86199, "has_logger_offset": true, "sort_key": [ 0, "Tide gauge" ], "connection_x": "14.00%", "connection_y": "15.62%", "connection_value_label": "+1.456 m", "connection_offset_top": "15.62%", "connection_offset_height": "73.44%", "connection_envelope_top": "10.94%", "connection_envelope_height": "9.37%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "ATIU-20260525-HISEAS-018", "category": "control", "category_label": "Gauge GPS tie", "label": "Tide gauge", "site_label": "ATIU-20260525-HISEAS-018", "note": "3.317 m field offset to logger. 132+200 =332cm tide gauge to dock surface", "date_label": "2026-05-25 17:21", "height_above_msl": "+1.484 m", "height_above_msl_m": 1.48447, "vertical_accuracy": "0.065 m", "vertical_accuracy_m": 0.06524, "envelope_lower_m": 1.35399, "envelope_upper_m": 1.61495, "envelope_label": "+1.354 m to +1.615 m", "precision": "0.004 m", "offset_position": "", "is_below": false, "logger_offset_label": "3.317 m field offset to logger", "logger_tie_m": -1.83303, "has_logger_offset": true, "sort_key": [ 0, "Tide gauge" ], "connection_x": "28.80%", "connection_y": "14.98%", "connection_value_label": "+1.484 m", "connection_offset_top": "14.98%", "connection_offset_height": "73.44%", "connection_envelope_top": "12.09%", "connection_envelope_height": "5.78%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "ATIU-20260528-HISEAS-011", "category": "reef-flat", "category_label": "Reef flat", "label": "Modern hard ground, Subaqueuos", "site_label": "Modern hard ground, Subaqueuos", "note": "Standing in water. Hard ground with modern coral atolls", "date_label": "2026-05-28 09:37", "height_above_msl": "-0.125 m", "height_above_msl_m": -0.125398, "vertical_accuracy": "0.082 m", "vertical_accuracy_m": 0.082424, "envelope_lower_m": -0.290246, "envelope_upper_m": 0.03945, "envelope_label": "-0.290 m to +0.039 m", "precision": "0.014 m", "offset_position": "45.82%", "is_below": true, "logger_offset_label": "", "connection_x": "43.60%", "connection_y": "50.62%", "connection_value_label": "-0.125 m", "connection_offset_top": "50.62%", "connection_offset_height": "0%", "connection_envelope_top": "46.97%", "connection_envelope_height": "7.30%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "ATIU-20260528-HISEAS-002", "category": "notch", "category_label": "Modern notch", "label": "HS106: Tarapaku / Ha'ai Makatea modern tidal notch", "site_label": "HS106: Tarapaku / Ha'ai Makatea", "note": "Tarapaku. Names a couple HS105 by mistake. This is hs106", "date_label": "2026-05-28 08:33", "height_above_msl": "-0.003 m", "height_above_msl_m": -0.002875, "vertical_accuracy": "0.892 m", "vertical_accuracy_m": 0.89183, "envelope_lower_m": -1.786535, "envelope_upper_m": 1.780785, "envelope_label": "-1.787 m to +1.781 m", "precision": "0.018 m", "offset_position": "49.90%", "is_below": true, "logger_offset_label": "", "connection_x": "58.40%", "connection_y": "47.91%", "connection_value_label": "-0.003 m", "connection_offset_top": "47.91%", "connection_offset_height": "0%", "connection_envelope_top": "8.42%", "connection_envelope_height": "78.97%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "ATIU-20260528-HISEAS-001", "category": "notch", "category_label": "Modern notch", "label": "HS106: Tarapaku / Ha'ai Makatea modern tidal notch", "site_label": "HS106: Tarapaku / Ha'ai Makatea", "note": "", "date_label": "2026-05-28 08:28", "height_above_msl": "+0.329 m", "height_above_msl_m": 0.328632, "vertical_accuracy": "0.364 m", "vertical_accuracy_m": 0.364263, "envelope_lower_m": -0.399894, "envelope_upper_m": 1.057158, "envelope_label": "-0.400 m to +1.057 m", "precision": "0.014 m", "offset_position": "60.95%", "is_below": false, "logger_offset_label": "", "connection_x": "73.20%", "connection_y": "40.57%", "connection_value_label": "+0.329 m", "connection_offset_top": "40.57%", "connection_offset_height": "0%", "connection_envelope_top": "24.44%", "connection_envelope_height": "32.25%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "ATIU-20260528-HISEAS-000", "category": "notch", "category_label": "Modern notch", "label": "HS106: Tarapaku / Ha'ai Makatea modern tidal notch", "site_label": "HS106: Tarapaku / Ha'ai Makatea", "note": "Tarapaku landing. Bottom of canoe ramp at modern tidal notch.", "date_label": "2026-05-28 08:22", "height_above_msl": "+0.509 m", "height_above_msl_m": 0.509045, "vertical_accuracy": "0.447 m", "vertical_accuracy_m": 0.44652, "envelope_lower_m": -0.383995, "envelope_upper_m": 1.402085, "envelope_label": "-0.384 m to +1.402 m", "precision": "0.010 m", "offset_position": "66.97%", "is_below": false, "logger_offset_label": "", "connection_x": "88.00%", "connection_y": "36.58%", "connection_value_label": "+0.509 m", "connection_offset_top": "36.58%", "connection_offset_height": "0%", "connection_envelope_top": "16.81%", "connection_envelope_height": "39.54%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false } ], "report_evidence_points": [ { "id": "ATIU-20260525-HISEAS-017", "category": "control", "category_label": "Gauge GPS tie", "label": "Tide gauge", "site_label": "ATIU-20260525-HISEAS-017", "note": "3.317 m field offset to logger. Dock above tide gauge. Reminder: Pole height is set to 0m. Must add pole height to measurement.", "date_label": "2026-05-25 17:16", "height_above_msl": "+1.456 m", "height_above_msl_m": 1.45551, "vertical_accuracy": "0.106 m", "vertical_accuracy_m": 0.105845, "envelope_lower_m": 1.24382, "envelope_upper_m": 1.6672, "envelope_label": "+1.244 m to +1.667 m", "precision": "0.016 m", "offset_position": "", "is_below": false, "logger_offset_label": "3.317 m field offset to logger", "logger_tie_m": -1.86199, "has_logger_offset": true, "sort_key": [ 0, "Tide gauge" ], "connection_x": "14.00%", "connection_y": "13.61%", "connection_value_label": "+1.456 m", "connection_offset_top": "13.61%", "connection_offset_height": "82.94%", "connection_envelope_top": "8.32%", "connection_envelope_height": "10.58%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "ATIU-20260528-HISEAS-011", "category": "reef-flat", "category_label": "Reef flat", "label": "Modern hard ground, Subaqueuos", "site_label": "Modern hard ground, Subaqueuos", "note": "Standing in water. Hard ground with modern coral atolls", "date_label": "2026-05-28 09:37", "height_above_msl": "-0.125 m", "height_above_msl_m": -0.125398, "vertical_accuracy": "0.082 m", "vertical_accuracy_m": 0.082424, "envelope_lower_m": -0.290246, "envelope_upper_m": 0.03945, "envelope_label": "-0.290 m to +0.039 m", "precision": "0.014 m", "offset_position": "45.82%", "is_below": true, "logger_offset_label": "", "connection_x": "51.00%", "connection_y": "53.13%", "connection_value_label": "-0.125 m", "connection_offset_top": "53.13%", "connection_offset_height": "0%", "connection_envelope_top": "49.01%", "connection_envelope_height": "8.24%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false, "report_label_position": "below" }, { "id": "ATIU-20260528-HISEAS-002", "category": "notch", "category_label": "Modern notch", "label": "HS106: Tarapaku / Ha'ai Makatea modern tidal notch", "site_label": "HS106: Tarapaku / Ha'ai Makatea", "note": "Tarapaku. Names a couple HS105 by mistake. This is hs106", "date_label": "2026-05-28 08:33", "height_above_msl": "-0.003 m", "height_above_msl_m": -0.002875, "vertical_accuracy": "0.892 m", "vertical_accuracy_m": 0.89183, "envelope_lower_m": -1.786535, "envelope_upper_m": 1.780785, "envelope_label": "-1.787 m to +1.781 m", "precision": "0.018 m", "offset_position": "49.90%", "is_below": true, "logger_offset_label": "", "connection_x": "88.00%", "connection_y": "50.07%", "connection_value_label": "-0.003 m", "connection_offset_top": "50.07%", "connection_offset_height": "0%", "connection_envelope_top": "5.48%", "connection_envelope_height": "89.18%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false, "report_label_position": "above" } ], "report_connection": { "axis_min_m": -2, "axis_max_m": 2, "axis_min_label": "-2.0 m", "axis_max_label": "+2.0 m", "datum_y": "50.00%", "logger_y": "96.19%", "logger_relative_m": -1.84751, "logger_relative_label": "-1.848 m", "point_count": 3 }, "evidence_filters": [ { "id": "all", "label": "All", "count": 6, "is_default": true }, { "id": "control", "label": "Gauge GPS tie", "count": 2, "is_default": false }, { "id": "reef-flat", "label": "Reef flat", "count": 1, "is_default": false }, { "id": "notch", "label": "Modern notch", "count": 3, "is_default": false } ], "evidence_count": 4, "connection": { "axis_min_m": -2.356077, "axis_max_m": 2.161287, "axis_min_label": "-2.356 m", "axis_max_label": "+2.161 m", "datum_y": "47.84%", "logger_y": "88.74%", "logger_relative_m": -1.84751, "logger_relative_label": "-1.848 m", "point_count": 6 }, "identity_image_url": "https://earth-history-uvic.s3.us-west-004.backblazeb2.com/web/photo-system/v1/thumb/2026/05/26/20260526-125005-cf2da8bd6a25-f5d8fffad193.jpg", "satellite_image_url": "https://server.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/export?bbox=-158.1703%2C-20.0553%2C-158.0547%2C-19.9397&bboxSR=4326&imageSR=4326&size=760%2C430&format=jpg&f=image" }, { "id": "mangaia", "island": "Mangaia", "href": "tidal-datums/mangaia/", "status": "applied", "display_date": "2026-06-01", "figure_title": "Mangaia Tide-Gauge Datum", "figure_path": "static/img/tide-gauge-datums/mangaia-datum.svg", "figure_alt": "Mangaia datum connection from HISEAS GPS control height, gauge offset, and pressure-derived mean water depth.", "plot_path": "static/img/tide-gauge-datums/mangaia-plot.svg", "report_plot_path": "static/img/tide-gauge-datums/mangaia-report-plot.svg", "report_record_days": 4, "plot_alt": "Mangaia tide-gauge water-depth logger record with local 6, 12, 18, and 24 hour markers.", "caption": "Mangaia: zero-corrected clipped mean water depth above logger 0.695 m and mean sea-level datum 12.472 m from the HISEAS GPS altitude reference.", "quality_note": "Uses the stable post-removal pressure plateau after the June 5 partial-retrieval drop as the zero-depth reference; this preserves the observed tidal oscillation while removing the apparent residual absolute-pressure offset.", "field_comment": "Cook Atlas notes mark direct tide-gauge GPS shots on June 1 and a second harbor tide-gauge measurement after lunch on June 2.", "datum_method": "direct_gauge_gps_plus_pressure_depth", "mean_sea_level_datum": "12.472 m", "mean_sea_level_datum_pole_removed": "10.253 m", "receiver_phase_center_offset": "2.2187 m", "receiver_pole_spike_height": "2.180 m", "receiver_mounting_bracket_height": "0.003 m", "receiver_arrow_gold_phase_center": "0.0357 m", "datum_reference_frame": "ITRF2008", "mean_clipped_water_depth": "0.695 m", "uncertainty": "-0.185 / +0.206 m", "uncertainty_note": "5-95% tide-depth window: 0.510 m to 0.902 m above logger.", "gauge_offset": "", "mean_control_altitude": "11.777 m", "mean_gauge_altitude": "11.777 m", "logger_relative_height": "-0.695 m", "deployment_time_local": "2026-06-01 13:20 CKT", "window_end_time_local": "2026-06-05 08:15 CKT", "control_point_ids": [ "MANGAIA-20260601-HISEAS-108", "MANGAIA-20260601-HISEAS-128", "MANGAIA-20260602-HISEAS-151", "MANGAIA-20260602-HISEAS-152" ], "gauge_location": { "id": "mangaia-tide-gauge", "label": "Mangaia harbor tide gauge", "short_label": "Tide gauge", "island": "Mangaia", "longitude": -157.95398275, "latitude": -21.911520687, "control_point_ids": [ "MANGAIA-20260601-HISEAS-108", "MANGAIA-20260601-HISEAS-128", "MANGAIA-20260602-HISEAS-151", "MANGAIA-20260602-HISEAS-152" ] }, "evidence_points": [ { "id": "MANGAIA-20260601-HISEAS-108", "category": "control", "category_label": "Gauge GPS tie", "label": "HS108: Mangaia Harbor tide gauge", "site_label": "HS108: Mangaia Harbor", "note": "Direct logger GPS tie. Collected by OMS, measured directly on tide gauge", "date_label": "2026-06-01 13:49", "height_above_msl": "-0.667 m", "height_above_msl_m": -0.666879, "vertical_accuracy": "0.068 m", "vertical_accuracy_m": 0.068235, "envelope_lower_m": -0.803349, "envelope_upper_m": -0.530409, "envelope_label": "-0.803 m to -0.530 m", "precision": "0.009 m", "offset_position": "", "is_below": true, "logger_offset_label": "Direct logger GPS tie", "logger_tie_m": -0.666879, "has_logger_offset": false, "sort_key": [ 0, "HS108: Mangaia Harbor tide gauge" ], "connection_x": "14.00%", "connection_y": "78.96%", "connection_value_label": "-0.667 m", "connection_offset_top": "78.96%", "connection_offset_height": "0%", "connection_envelope_top": "72.57%", "connection_envelope_height": "12.79%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "MANGAIA-20260601-HISEAS-128", "category": "control", "category_label": "Gauge GPS tie", "label": "HS108: Mangaia Harbor Tide gauge Mangaia harbor", "site_label": "HS108: Mangaia Harbor", "note": "Direct logger GPS tie. Measured directly on tide gauge", "date_label": "2026-06-01 13:55", "height_above_msl": "-0.663 m", "height_above_msl_m": -0.662819, "vertical_accuracy": "0.068 m", "vertical_accuracy_m": 0.06822, "envelope_lower_m": -0.799259, "envelope_upper_m": -0.526379, "envelope_label": "-0.799 m to -0.526 m", "precision": "0.004 m", "offset_position": "", "is_below": true, "logger_offset_label": "Direct logger GPS tie", "logger_tie_m": -0.662819, "has_logger_offset": false, "sort_key": [ 0, "HS108: Mangaia Harbor Tide gauge Mangaia harbor" ], "connection_x": "22.22%", "connection_y": "78.77%", "connection_value_label": "-0.663 m", "connection_offset_top": "78.77%", "connection_offset_height": "0%", "connection_envelope_top": "72.38%", "connection_envelope_height": "12.79%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "MANGAIA-20260602-HISEAS-151", "category": "control", "category_label": "Gauge GPS tie", "label": "Tide gauge", "site_label": "Tide gauge", "note": "Direct logger GPS tie. Return to tide gauge at harbor", "date_label": "2026-06-02 12:45", "height_above_msl": "-0.712 m", "height_above_msl_m": -0.712399, "vertical_accuracy": "0.073 m", "vertical_accuracy_m": 0.07267, "envelope_lower_m": -0.857739, "envelope_upper_m": -0.567059, "envelope_label": "-0.858 m to -0.567 m", "precision": "0.004 m", "offset_position": "", "is_below": true, "logger_offset_label": "Direct logger GPS tie", "logger_tie_m": -0.712399, "has_logger_offset": false, "sort_key": [ 0, "Tide gauge" ], "connection_x": "30.44%", "connection_y": "81.10%", "connection_value_label": "-0.712 m", "connection_offset_top": "81.10%", "connection_offset_height": "0%", "connection_envelope_top": "74.29%", "connection_envelope_height": "13.62%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "MANGAIA-20260602-HISEAS-152", "category": "control", "category_label": "Gauge GPS tie", "label": "Tide gauge", "site_label": "Tide gauge", "note": "Direct logger GPS tie", "date_label": "2026-06-02 12:47", "height_above_msl": "-0.739 m", "height_above_msl_m": -0.739039, "vertical_accuracy": "0.072 m", "vertical_accuracy_m": 0.07166, "envelope_lower_m": -0.882359, "envelope_upper_m": -0.595719, "envelope_label": "-0.882 m to -0.596 m", "precision": "0.003 m", "offset_position": "", "is_below": true, "logger_offset_label": "Direct logger GPS tie", "logger_tie_m": -0.739039, "has_logger_offset": false, "sort_key": [ 0, "Tide gauge" ], "connection_x": "38.67%", "connection_y": "82.35%", "connection_value_label": "-0.739 m", "connection_offset_top": "82.35%", "connection_offset_height": "0%", "connection_envelope_top": "75.63%", "connection_envelope_height": "13.43%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "MANGAIA-20260602-HISEAS-134", "category": "waterline", "category_label": "Waterline", "label": "HS110: Araoa Cave water level", "site_label": "HS110: Araoa Cave", "note": "Second measurement", "date_label": "2026-06-02 09:42", "height_above_msl": "+0.009 m", "height_above_msl_m": 0.008641, "vertical_accuracy": "0.095 m", "vertical_accuracy_m": 0.09512, "envelope_lower_m": -0.181599, "envelope_upper_m": 0.198881, "envelope_label": "-0.182 m to +0.199 m", "precision": "0.007 m", "offset_position": "50.29%", "is_below": false, "logger_offset_label": "", "connection_x": "46.89%", "connection_y": "47.31%", "connection_value_label": "+0.009 m", "connection_offset_top": "47.31%", "connection_offset_height": "0%", "connection_envelope_top": "38.39%", "connection_envelope_height": "17.83%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "MANGAIA-20260602-HISEAS-133", "category": "waterline", "category_label": "Waterline", "label": "HS110: Araoa Cave shoreline, in surf", "site_label": "HS110: Araoa Cave", "note": "Araoa beach", "date_label": "2026-06-02 09:28", "height_above_msl": "+0.116 m", "height_above_msl_m": 0.116001, "vertical_accuracy": "0.134 m", "vertical_accuracy_m": 0.13403, "envelope_lower_m": -0.152059, "envelope_upper_m": 0.384061, "envelope_label": "-0.152 m to +0.384 m", "precision": "0.005 m", "offset_position": "53.87%", "is_below": false, "logger_offset_label": "", "connection_x": "55.11%", "connection_y": "42.28%", "connection_value_label": "+0.116 m", "connection_offset_top": "42.28%", "connection_offset_height": "0%", "connection_envelope_top": "29.71%", "connection_envelope_height": "25.12%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "MANGAIA-20260602-HISEAS-139", "category": "waterline", "category_label": "Waterline", "label": "HS110: Araoa Cave GCP5", "site_label": "HS110: Araoa Cave", "note": "HS110, estimated at 40cm above waterline", "date_label": "2026-06-02 10:06", "height_above_msl": "+0.785 m", "height_above_msl_m": 0.784691, "vertical_accuracy": "1.927 m", "vertical_accuracy_m": 1.92669, "envelope_lower_m": -3.068689, "envelope_upper_m": 4.638071, "envelope_label": "-3.069 m to +4.638 m", "precision": "0.007 m", "offset_position": "76.16%", "is_below": false, "logger_offset_label": "", "connection_x": "63.33%", "connection_y": "10.94%", "connection_value_label": "+0.785 m", "connection_offset_top": "10.94%", "connection_offset_height": "0%", "connection_envelope_top": "0.00%", "connection_envelope_height": "100.00%", "has_envelope": true, "envelope_clipped_top": true, "envelope_clipped_bottom": true }, { "id": "MANGAIA-20260602-HISEAS-145", "category": "reef-flat", "category_label": "Reef flat", "label": "Hard ground just seaward of sandy beach", "site_label": "Hard ground just seaward of sandy beach", "note": "", "date_label": "2026-06-02 10:32", "height_above_msl": "-0.059 m", "height_above_msl_m": -0.058899, "vertical_accuracy": "0.135 m", "vertical_accuracy_m": 0.13481, "envelope_lower_m": -0.328519, "envelope_upper_m": 0.210721, "envelope_label": "-0.329 m to +0.211 m", "precision": "0.016 m", "offset_position": "48.04%", "is_below": true, "logger_offset_label": "", "connection_x": "71.56%", "connection_y": "50.47%", "connection_value_label": "-0.059 m", "connection_offset_top": "50.47%", "connection_offset_height": "0%", "connection_envelope_top": "37.84%", "connection_envelope_height": "25.27%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "MANGAIA-20260601-HISEAS-126", "category": "reef-flat", "category_label": "Reef flat", "label": "HS108: Mangaia Harbor", "site_label": "HS108: Mangaia Harbor", "note": "", "date_label": "2026-06-01 13:48", "height_above_msl": "-0.095 m", "height_above_msl_m": -0.094899, "vertical_accuracy": "0.069 m", "vertical_accuracy_m": 0.069, "envelope_lower_m": -0.232899, "envelope_upper_m": 0.043101, "envelope_label": "-0.233 m to +0.043 m", "precision": "", "offset_position": "46.84%", "is_below": true, "logger_offset_label": "", "connection_x": "79.78%", "connection_y": "52.16%", "connection_value_label": "-0.095 m", "connection_offset_top": "52.16%", "connection_offset_height": "0%", "connection_envelope_top": "45.69%", "connection_envelope_height": "12.93%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "MANGAIA-20260601-HISEAS-127", "category": "reef-flat", "category_label": "Reef flat", "label": "HS108: Mangaia Harbor", "site_label": "HS108: Mangaia Harbor", "note": "HS108", "date_label": "2026-06-01 13:49", "height_above_msl": "-0.128 m", "height_above_msl_m": -0.128219, "vertical_accuracy": "0.068 m", "vertical_accuracy_m": 0.06832, "envelope_lower_m": -0.264859, "envelope_upper_m": 0.008421, "envelope_label": "-0.265 m to +0.008 m", "precision": "0.003 m", "offset_position": "45.73%", "is_below": true, "logger_offset_label": "", "connection_x": "88.00%", "connection_y": "53.72%", "connection_value_label": "-0.128 m", "connection_offset_top": "53.72%", "connection_offset_height": "0%", "connection_envelope_top": "47.32%", "connection_envelope_height": "12.81%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false } ], "report_evidence_points": [ { "id": "MANGAIA-20260601-HISEAS-108", "category": "control", "category_label": "Gauge GPS tie", "label": "HS108: Mangaia Harbor tide gauge", "site_label": "HS108: Mangaia Harbor", "note": "Direct logger GPS tie. Collected by OMS, measured directly on tide gauge", "date_label": "2026-06-01 13:49", "height_above_msl": "-0.667 m", "height_above_msl_m": -0.666879, "vertical_accuracy": "0.068 m", "vertical_accuracy_m": 0.068235, "envelope_lower_m": -0.803349, "envelope_upper_m": -0.530409, "envelope_label": "-0.803 m to -0.530 m", "precision": "0.009 m", "offset_position": "", "is_below": true, "logger_offset_label": "Direct logger GPS tie", "logger_tie_m": -0.666879, "has_logger_offset": false, "sort_key": [ 0, "HS108: Mangaia Harbor tide gauge" ], "connection_x": "14.00%", "connection_y": "83.34%", "connection_value_label": "-0.667 m", "connection_offset_top": "83.34%", "connection_offset_height": "0%", "connection_envelope_top": "76.52%", "connection_envelope_height": "13.65%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "MANGAIA-20260602-HISEAS-134", "category": "waterline", "category_label": "Waterline", "label": "HS110: Araoa Cave water level", "site_label": "HS110: Araoa Cave", "note": "Second measurement", "date_label": "2026-06-02 09:42", "height_above_msl": "+0.009 m", "height_above_msl_m": 0.008641, "vertical_accuracy": "0.095 m", "vertical_accuracy_m": 0.09512, "envelope_lower_m": -0.181599, "envelope_upper_m": 0.198881, "envelope_label": "-0.182 m to +0.199 m", "precision": "0.007 m", "offset_position": "50.29%", "is_below": false, "logger_offset_label": "", "connection_x": "51.00%", "connection_y": "49.57%", "connection_value_label": "+0.009 m", "connection_offset_top": "49.57%", "connection_offset_height": "0%", "connection_envelope_top": "40.06%", "connection_envelope_height": "19.02%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false, "report_label_position": "above" }, { "id": "MANGAIA-20260602-HISEAS-145", "category": "reef-flat", "category_label": "Reef flat", "label": "Hard ground just seaward of sandy beach", "site_label": "Hard ground just seaward of sandy beach", "note": "", "date_label": "2026-06-02 10:32", "height_above_msl": "-0.059 m", "height_above_msl_m": -0.058899, "vertical_accuracy": "0.135 m", "vertical_accuracy_m": 0.13481, "envelope_lower_m": -0.328519, "envelope_upper_m": 0.210721, "envelope_label": "-0.329 m to +0.211 m", "precision": "0.016 m", "offset_position": "48.04%", "is_below": true, "logger_offset_label": "", "connection_x": "88.00%", "connection_y": "52.94%", "connection_value_label": "-0.059 m", "connection_offset_top": "52.94%", "connection_offset_height": "0%", "connection_envelope_top": "39.46%", "connection_envelope_height": "26.96%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false, "report_label_position": "below" } ], "report_connection": { "axis_min_m": -1.0, "axis_max_m": 1.0, "axis_min_label": "-1.0 m", "axis_max_label": "+1.0 m", "datum_y": "50.00%", "logger_y": "84.76%", "logger_relative_m": -0.695284, "logger_relative_label": "-0.695 m", "point_count": 3 }, "evidence_filters": [ { "id": "all", "label": "All", "count": 10, "is_default": true }, { "id": "control", "label": "Gauge GPS tie", "count": 4, "is_default": false }, { "id": "waterline", "label": "Waterline", "count": 3, "is_default": false }, { "id": "reef-flat", "label": "Reef flat", "count": 3, "is_default": false } ], "evidence_count": 6, "connection": { "axis_min_m": -1.115746, "axis_max_m": 1.018078, "axis_min_label": "-1.116 m", "axis_max_label": "+1.018 m", "datum_y": "47.71%", "logger_y": "80.30%", "logger_relative_m": -0.695284, "logger_relative_label": "-0.695 m", "point_count": 10 }, "identity_image_url": "https://earth-history-uvic.s3.us-west-004.backblazeb2.com/web/photo-system/v1/thumb/2026/06/01/20260601-135547-0bcc8926b871-cf7342eb64f5.jpg", "satellite_image_url": "https://server.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/export?bbox=-157.988%2C-21.9871%2C-157.852%2C-21.8579&bboxSR=4326&imageSR=4326&size=760%2C430&format=jpg&f=image" }, { "id": "mauke", "island": "Mauke", "href": "tidal-datums/mauke/", "status": "applied", "display_date": "2026-06-05", "figure_title": "Mauke Tide-Gauge Datum", "figure_path": "static/img/tide-gauge-datums/mauke-datum.svg", "figure_alt": "Mauke datum connection from HISEAS GPS control height, gauge offset, and pressure-derived mean water depth.", "plot_path": "static/img/tide-gauge-datums/mauke-plot.svg", "report_plot_path": "static/img/tide-gauge-datums/mauke-report-plot.svg", "report_record_days": 3, "plot_alt": "Mauke tide-gauge water-depth logger record with local 6, 12, 18, and 24 hour markers.", "caption": "Mauke: zero-corrected clipped mean water depth above logger 0.503 m and mean sea-level datum 12.525 m from the HISEAS GPS altitude reference.", "quality_note": "Uses smaller per-island pressure-jump thresholds because the Mauke deployment/retrieval steps are shallower than the Atiu and Mangaia harbor records.", "field_comment": "Cook Atlas note for MAUKE-20260605-HISEAS-239 records the GPS base on the sea wall 2.70 m above the tide gauge; recorder notes place the gauge in a protected harbor hole near low tide.", "datum_method": "dock_gps_minus_field_offset_plus_pressure_depth", "mean_sea_level_datum": "12.525 m", "mean_sea_level_datum_pole_removed": "10.306 m", "receiver_phase_center_offset": "2.2187 m", "receiver_pole_spike_height": "2.180 m", "receiver_mounting_bracket_height": "0.003 m", "receiver_arrow_gold_phase_center": "0.0357 m", "datum_reference_frame": "ITRF2008", "mean_clipped_water_depth": "0.503 m", "uncertainty": "-0.223 / +0.213 m", "uncertainty_note": "5-95% tide-depth window: 0.280 m to 0.717 m above logger.", "gauge_offset": "2.700 m", "mean_control_altitude": "14.722 m", "mean_gauge_altitude": "12.022 m", "logger_relative_height": "-0.503 m", "deployment_time_local": "2026-06-05 17:06 CKT", "window_end_time_local": "2026-06-08 07:31 CKT", "control_point_ids": [ "MAUKE-20260605-HISEAS-239" ], "gauge_location": { "id": "mauke-tide-gauge", "label": "Mauke harbor tide gauge", "short_label": "Tide gauge", "island": "Mauke", "longitude": -157.358345987, "latitude": -20.145577156, "control_point_ids": [ "MAUKE-20260605-HISEAS-239" ] }, "evidence_points": [ { "id": "MAUKE-20260605-HISEAS-239", "category": "control", "category_label": "Gauge GPS tie", "label": "Mauke harbor tide gauge", "site_label": "Mauke harbor tide gauge", "note": "2.700 m field offset to logger. Measuring on top of the sea wall. Height of GPS base above tide gauge is 2.70m.", "date_label": "2026-06-05 17:13", "height_above_msl": "+2.197 m", "height_above_msl_m": 2.19683, "vertical_accuracy": "0.100 m", "vertical_accuracy_m": 0.10002, "envelope_lower_m": 1.99679, "envelope_upper_m": 2.39687, "envelope_label": "+1.997 m to +2.397 m", "precision": "0.014 m", "offset_position": "", "is_below": false, "logger_offset_label": "2.700 m field offset to logger", "logger_tie_m": -0.50317, "has_logger_offset": true, "sort_key": [ 0, "Mauke harbor tide gauge" ], "connection_x": "14.00%", "connection_y": "16.15%", "connection_value_label": "+2.197 m", "connection_offset_top": "16.15%", "connection_offset_height": "70.39%", "connection_envelope_top": "10.94%", "connection_envelope_height": "10.43%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "MAUKE-20260606-HISEAS-252", "category": "waterline", "category_label": "Waterline", "label": "HS117: West-Side Layers modern shoreline", "site_label": "HS117: West-Side Layers", "note": "", "date_label": "2026-06-06 13:58", "height_above_msl": "-0.062 m", "height_above_msl_m": -0.06243, "vertical_accuracy": "0.269 m", "vertical_accuracy_m": 0.26877, "envelope_lower_m": -0.59997, "envelope_upper_m": 0.47511, "envelope_label": "-0.600 m to +0.475 m", "precision": "0.008 m", "offset_position": "47.92%", "is_below": true, "logger_offset_label": "", "connection_x": "22.22%", "connection_y": "75.05%", "connection_value_label": "-0.062 m", "connection_offset_top": "75.05%", "connection_offset_height": "0%", "connection_envelope_top": "61.04%", "connection_envelope_height": "28.03%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "MAUKE-20260607-HISEAS-282", "category": "waterline", "category_label": "Waterline", "label": "HS119: Uriaata exposed reef flat near shore", "site_label": "HS119: Uriaata", "note": "This is near the pile of organs presumably low tide rn, exposed reef a few cm above water pools", "date_label": "2026-06-07 10:07", "height_above_msl": "+0.067 m", "height_above_msl_m": 0.06691, "vertical_accuracy": "0.070 m", "vertical_accuracy_m": 0.069899, "envelope_lower_m": -0.072888, "envelope_upper_m": 0.206708, "envelope_label": "-0.073 m to +0.207 m", "precision": "0.003 m", "offset_position": "52.23%", "is_below": false, "logger_offset_label": "", "connection_x": "30.44%", "connection_y": "71.68%", "connection_value_label": "+0.067 m", "connection_offset_top": "71.68%", "connection_offset_height": "0%", "connection_envelope_top": "68.03%", "connection_envelope_height": "7.29%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "MAUKE-20260607-HISEAS-297", "category": "waterline", "category_label": "Waterline", "label": "Water line Oneunga", "site_label": "Water line Oneunga", "note": "", "date_label": "2026-06-07 12:14", "height_above_msl": "-0.196 m", "height_above_msl_m": -0.19572, "vertical_accuracy": "0.155 m", "vertical_accuracy_m": 0.15549, "envelope_lower_m": -0.5067, "envelope_upper_m": 0.11526, "envelope_label": "-0.507 m to +0.115 m", "precision": "0.029 m", "offset_position": "43.48%", "is_below": true, "logger_offset_label": "", "connection_x": "38.67%", "connection_y": "78.52%", "connection_value_label": "-0.196 m", "connection_offset_top": "78.52%", "connection_offset_height": "0%", "connection_envelope_top": "70.42%", "connection_envelope_height": "16.21%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "MAUKE-20260607-HISEAS-298", "category": "waterline", "category_label": "Waterline", "label": "Waterline Oneunga", "site_label": "Waterline Oneunga", "note": "", "date_label": "2026-06-07 12:16", "height_above_msl": "-0.234 m", "height_above_msl_m": -0.23374, "vertical_accuracy": "0.138 m", "vertical_accuracy_m": 0.1375, "envelope_lower_m": -0.50874, "envelope_upper_m": 0.04126, "envelope_label": "-0.509 m to +0.041 m", "precision": "0.002 m", "offset_position": "42.21%", "is_below": true, "logger_offset_label": "", "connection_x": "46.89%", "connection_y": "79.52%", "connection_value_label": "-0.234 m", "connection_offset_top": "79.52%", "connection_offset_height": "0%", "connection_envelope_top": "72.35%", "connection_envelope_height": "14.34%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "MAUKE-20260607-HISEAS-299", "category": "waterline", "category_label": "Waterline", "label": "HS120: Arapaea Waterline Ana Takapua", "site_label": "HS120: Arapaea", "note": "", "date_label": "2026-06-07 13:12", "height_above_msl": "+0.296 m", "height_above_msl_m": 0.29646, "vertical_accuracy": "0.085 m", "vertical_accuracy_m": 0.08494, "envelope_lower_m": 0.12658, "envelope_upper_m": 0.46634, "envelope_label": "+0.127 m to +0.466 m", "precision": "0.005 m", "offset_position": "59.88%", "is_below": false, "logger_offset_label": "", "connection_x": "55.11%", "connection_y": "65.69%", "connection_value_label": "+0.296 m", "connection_offset_top": "65.69%", "connection_offset_height": "0%", "connection_envelope_top": "61.26%", "connection_envelope_height": "8.86%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "MAUKE-20260606-HISEAS-245", "category": "waterline", "category_label": "Waterline", "label": "HS116: Anaraura shoreline", "site_label": "HS116: Anaraura", "note": "Mas o menos. Hola Blake!", "date_label": "2026-06-06 11:09", "height_above_msl": "+0.307 m", "height_above_msl_m": 0.30731, "vertical_accuracy": "0.079 m", "vertical_accuracy_m": 0.07885, "envelope_lower_m": 0.14961, "envelope_upper_m": 0.46501, "envelope_label": "+0.150 m to +0.465 m", "precision": "0.003 m", "offset_position": "60.24%", "is_below": false, "logger_offset_label": "", "connection_x": "63.33%", "connection_y": "65.41%", "connection_value_label": "+0.307 m", "connection_offset_top": "65.41%", "connection_offset_height": "0%", "connection_envelope_top": "61.30%", "connection_envelope_height": "8.22%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "MAUKE-20260606-HISEAS-246", "category": "waterline", "category_label": "Waterline", "label": "HS116: Anaraura modern shoreline", "site_label": "HS116: Anaraura", "note": "", "date_label": "2026-06-06 11:16", "height_above_msl": "+0.367 m", "height_above_msl_m": 0.36651, "vertical_accuracy": "0.069 m", "vertical_accuracy_m": 0.06899, "envelope_lower_m": 0.22853, "envelope_upper_m": 0.50449, "envelope_label": "+0.229 m to +0.504 m", "precision": "0.005 m", "offset_position": "62.22%", "is_below": false, "logger_offset_label": "", "connection_x": "71.56%", "connection_y": "63.87%", "connection_value_label": "+0.367 m", "connection_offset_top": "63.87%", "connection_offset_height": "0%", "connection_envelope_top": "60.27%", "connection_envelope_height": "7.19%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "MAUKE-20260607-HISEAS-283", "category": "waterline", "category_label": "Waterline", "label": "HS119: Uriaata highest exposed living green algal mat", "site_label": "HS119: Uriaata", "note": "Highest living green algal mat exposed at low tide rn", "date_label": "2026-06-07 10:09", "height_above_msl": "+0.500 m", "height_above_msl_m": 0.499829, "vertical_accuracy": "0.074 m", "vertical_accuracy_m": 0.073818, "envelope_lower_m": 0.352193, "envelope_upper_m": 0.647465, "envelope_label": "+0.352 m to +0.647 m", "precision": "0.002 m", "offset_position": "66.66%", "is_below": false, "logger_offset_label": "", "connection_x": "79.78%", "connection_y": "60.39%", "connection_value_label": "+0.500 m", "connection_offset_top": "60.39%", "connection_offset_height": "0%", "connection_envelope_top": "56.54%", "connection_envelope_height": "7.70%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "MAUKE-20260607-HISEAS-281", "category": "reef-flat", "category_label": "Reef flat", "label": "Modern reef flat front", "site_label": "Modern reef flat front", "note": "Wave run up lapping over pole bottom. Lots of pink algae, this is the crest before thee fore reef slope", "date_label": "2026-06-07 10:01", "height_above_msl": "+0.361 m", "height_above_msl_m": 0.36107, "vertical_accuracy": "0.064 m", "vertical_accuracy_m": 0.06384, "envelope_lower_m": 0.23339, "envelope_upper_m": 0.48875, "envelope_label": "+0.233 m to +0.489 m", "precision": "0.002 m", "offset_position": "62.04%", "is_below": false, "logger_offset_label": "", "connection_x": "88.00%", "connection_y": "64.01%", "connection_value_label": "+0.361 m", "connection_offset_top": "64.01%", "connection_offset_height": "0%", "connection_envelope_top": "60.68%", "connection_envelope_height": "6.66%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false } ], "report_evidence_points": [ { "id": "MAUKE-20260605-HISEAS-239", "category": "control", "category_label": "Gauge GPS tie", "label": "Mauke harbor tide gauge", "site_label": "Mauke harbor tide gauge", "note": "2.700 m field offset to logger. Measuring on top of the sea wall. Height of GPS base above tide gauge is 2.70m.", "date_label": "2026-06-05 17:13", "height_above_msl": "+2.197 m", "height_above_msl_m": 2.19683, "vertical_accuracy": "0.100 m", "vertical_accuracy_m": 0.10002, "envelope_lower_m": 1.99679, "envelope_upper_m": 2.39687, "envelope_label": "+1.997 m to +2.397 m", "precision": "0.014 m", "offset_position": "", "is_below": false, "logger_offset_label": "2.700 m field offset to logger", "logger_tie_m": -0.50317, "has_logger_offset": true, "sort_key": [ 0, "Mauke harbor tide gauge" ], "connection_x": "14.00%", "connection_y": "13.39%", "connection_value_label": "+2.197 m", "connection_offset_top": "13.39%", "connection_offset_height": "45.00%", "connection_envelope_top": "10.05%", "connection_envelope_height": "6.67%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "MAUKE-20260606-HISEAS-252", "category": "waterline", "category_label": "Waterline", "label": "HS117: West-Side Layers modern shoreline", "site_label": "HS117: West-Side Layers", "note": "", "date_label": "2026-06-06 13:58", "height_above_msl": "-0.062 m", "height_above_msl_m": -0.06243, "vertical_accuracy": "0.269 m", "vertical_accuracy_m": 0.26877, "envelope_lower_m": -0.59997, "envelope_upper_m": 0.47511, "envelope_label": "-0.600 m to +0.475 m", "precision": "0.008 m", "offset_position": "47.92%", "is_below": true, "logger_offset_label": "", "connection_x": "51.00%", "connection_y": "51.04%", "connection_value_label": "-0.062 m", "connection_offset_top": "51.04%", "connection_offset_height": "0%", "connection_envelope_top": "42.08%", "connection_envelope_height": "17.92%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false, "report_label_position": "below" }, { "id": "MAUKE-20260607-HISEAS-281", "category": "reef-flat", "category_label": "Reef flat", "label": "Modern reef flat front", "site_label": "Modern reef flat front", "note": "Wave run up lapping over pole bottom. Lots of pink algae, this is the crest before thee fore reef slope", "date_label": "2026-06-07 10:01", "height_above_msl": "+0.361 m", "height_above_msl_m": 0.36107, "vertical_accuracy": "0.064 m", "vertical_accuracy_m": 0.06384, "envelope_lower_m": 0.23339, "envelope_upper_m": 0.48875, "envelope_label": "+0.233 m to +0.489 m", "precision": "0.002 m", "offset_position": "62.04%", "is_below": false, "logger_offset_label": "", "connection_x": "88.00%", "connection_y": "43.98%", "connection_value_label": "+0.361 m", "connection_offset_top": "43.98%", "connection_offset_height": "0%", "connection_envelope_top": "41.85%", "connection_envelope_height": "4.26%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false, "report_label_position": "above" } ], "report_connection": { "axis_min_m": -3, "axis_max_m": 3, "axis_min_label": "-3.0 m", "axis_max_label": "+3.0 m", "datum_y": "50.00%", "logger_y": "58.39%", "logger_relative_m": -0.50317, "logger_relative_label": "-0.503 m", "point_count": 3 }, "evidence_filters": [ { "id": "all", "label": "All", "count": 10, "is_default": true }, { "id": "control", "label": "Gauge GPS tie", "count": 1, "is_default": false }, { "id": "waterline", "label": "Waterline", "count": 8, "is_default": false }, { "id": "reef-flat", "label": "Reef flat", "count": 1, "is_default": false } ], "evidence_count": 9, "connection": { "axis_min_m": -1.019528, "axis_max_m": 2.816428, "axis_min_label": "-1.020 m", "axis_max_label": "+2.816 m", "datum_y": "73.42%", "logger_y": "86.54%", "logger_relative_m": -0.50317, "logger_relative_label": "-0.503 m", "point_count": 10 }, "identity_image_url": "https://earth-history-uvic.s3.us-west-004.backblazeb2.com/web/photo-system/v1/thumb/2026/06/06/20260606-104317-ecd0b79a1532-5d620db72cae.jpg", "satellite_image_url": "https://server.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/export?bbox=-157.3876%2C-20.2144%2C-157.2924%2C-20.1056&bboxSR=4326&imageSR=4326&size=760%2C430&format=jpg&f=image" }, { "id": "mitiaro", "island": "Mitiaro", "href": "tidal-datums/mitiaro/", "status": "applied", "display_date": "2026-06-09", "figure_title": "Mitiaro Tide-Gauge Datum", "figure_path": "static/img/tide-gauge-datums/mitiaro-datum.svg", "figure_alt": "Mitiaro datum connection from HISEAS GPS control height, gauge offset, and pressure-derived mean water depth.", "plot_path": "static/img/tide-gauge-datums/mitiaro-plot.svg", "report_plot_path": "static/img/tide-gauge-datums/mitiaro-report-plot.svg", "report_record_days": 3, "plot_alt": "Mitiaro tide-gauge water-depth logger record with local 6, 12, 18, and 24 hour markers.", "caption": "Mitiaro: zero-corrected clipped mean water depth above logger 0.920 m and mean sea-level datum 13.515 m from the HISEAS GPS altitude reference.", "quality_note": "Uses the explicit deployment and recovery dock-surface GPS ties; the field notes flag the gauge-rock offset as the controlling vertical tie. Uses the initial air interval for the pressure zero because the hour before deployment includes wet handling.", "field_comment": "Cook Atlas notes tie both Mitiaro harbor tide-gauge GPS shots to the dock/concrete surface above the gauge; recorder notes record that surface 1.91 m above the tide-gauge rock.", "datum_method": "dock_gps_minus_field_offset_plus_pressure_depth", "mean_sea_level_datum": "13.515 m", "mean_sea_level_datum_pole_removed": "11.296 m", "receiver_phase_center_offset": "2.2187 m", "receiver_pole_spike_height": "2.180 m", "receiver_mounting_bracket_height": "0.003 m", "receiver_arrow_gold_phase_center": "0.0357 m", "datum_reference_frame": "ITRF2008", "mean_clipped_water_depth": "0.920 m", "uncertainty": "-0.382 / +0.451 m", "uncertainty_note": "5-95% tide-depth window: 0.537 m to 1.371 m above logger.", "gauge_offset": "1.910 m", "mean_control_altitude": "14.505 m", "mean_gauge_altitude": "12.595 m", "logger_relative_height": "-0.920 m", "deployment_time_local": "2026-06-09 17:37 CKT", "window_end_time_local": "2026-06-12 08:54 CKT", "control_point_ids": [ "MITIARO-20260609-HISEAS-341", "MITIARO-20260612-HISEAS-415" ], "gauge_location": { "id": "mitiaro-tide-gauge", "label": "Mitiaro harbor tide gauge", "short_label": "Tide gauge", "island": "Mitiaro", "longitude": -157.720714599, "latitude": -19.861994, "control_point_ids": [ "MITIARO-20260609-HISEAS-341", "MITIARO-20260612-HISEAS-415" ] }, "evidence_points": [ { "id": "MITIARO-20260609-HISEAS-341", "category": "control", "category_label": "Gauge GPS tie", "label": "Tide gauge Mitiaro", "site_label": "Tide gauge Mitiaro", "note": "1.910 m field offset to logger. Dock above tide gauge, where rope reaches dock surface", "date_label": "2026-06-09 09:06", "height_above_msl": "+0.965 m", "height_above_msl_m": 0.965117, "vertical_accuracy": "0.128 m", "vertical_accuracy_m": 0.12825, "envelope_lower_m": 0.708617, "envelope_upper_m": 1.221617, "envelope_label": "+0.709 m to +1.222 m", "precision": "0.005 m", "offset_position": "", "is_below": false, "logger_offset_label": "1.910 m field offset to logger", "logger_tie_m": -0.944883, "has_logger_offset": true, "sort_key": [ 0, "Tide gauge Mitiaro" ], "connection_x": "14.00%", "connection_y": "26.76%", "connection_value_label": "+0.965 m", "connection_offset_top": "26.76%", "connection_offset_height": "62.30%", "connection_envelope_top": "18.39%", "connection_envelope_height": "16.73%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "MITIARO-20260612-HISEAS-415", "category": "control", "category_label": "Gauge GPS tie", "label": "Tide gauge in Mitiaro harbor", "site_label": "Tide gauge in Mitiaro harbor", "note": "1.910 m field offset to logger. Collection of tide gauge, surface of dock above tide gauge", "date_label": "2026-06-12 10:11", "height_above_msl": "+1.015 m", "height_above_msl_m": 1.015487, "vertical_accuracy": "0.070 m", "vertical_accuracy_m": 0.07017, "envelope_lower_m": 0.875147, "envelope_upper_m": 1.155827, "envelope_label": "+0.875 m to +1.156 m", "precision": "0.004 m", "offset_position": "", "is_below": false, "logger_offset_label": "1.910 m field offset to logger", "logger_tie_m": -0.894513, "has_logger_offset": true, "sort_key": [ 0, "Tide gauge in Mitiaro harbor" ], "connection_x": "24.57%", "connection_y": "25.12%", "connection_value_label": "+1.015 m", "connection_offset_top": "25.12%", "connection_offset_height": "62.30%", "connection_envelope_top": "20.54%", "connection_envelope_height": "9.16%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "MITIARO-20260611-HISEAS-404", "category": "waterline", "category_label": "Waterline", "label": "Waterline Chris\u2019s beach", "site_label": "Waterline Chris\u2019s beach", "note": "", "date_label": "2026-06-11 14:53", "height_above_msl": "-0.076 m", "height_above_msl_m": -0.075903, "vertical_accuracy": "0.064 m", "vertical_accuracy_m": 0.06408, "envelope_lower_m": -0.204063, "envelope_upper_m": 0.052257, "envelope_label": "-0.204 m to +0.052 m", "precision": "0.003 m", "offset_position": "47.47%", "is_below": true, "logger_offset_label": "", "connection_x": "35.14%", "connection_y": "60.72%", "connection_value_label": "-0.076 m", "connection_offset_top": "60.72%", "connection_offset_height": "0%", "connection_envelope_top": "56.54%", "connection_envelope_height": "8.36%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "MITIARO-20260610-HISEAS-378", "category": "waterline", "category_label": "Waterline", "label": "Modern waterline on reef flat", "site_label": "Modern waterline on reef flat", "note": "", "date_label": "2026-06-10 12:14", "height_above_msl": "-0.124 m", "height_above_msl_m": -0.123603, "vertical_accuracy": "0.165 m", "vertical_accuracy_m": 0.16512, "envelope_lower_m": -0.453843, "envelope_upper_m": 0.206637, "envelope_label": "-0.454 m to +0.207 m", "precision": "0.013 m", "offset_position": "45.88%", "is_below": true, "logger_offset_label": "", "connection_x": "45.71%", "connection_y": "62.27%", "connection_value_label": "-0.124 m", "connection_offset_top": "62.27%", "connection_offset_height": "0%", "connection_envelope_top": "51.50%", "connection_envelope_height": "21.54%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "MITIARO-20260609-HISEAS-365", "category": "waterline", "category_label": "Waterline", "label": "HS122: Teunu waterline modern shore", "site_label": "HS122: Teunu", "note": "", "date_label": "2026-06-09 16:15", "height_above_msl": "+0.257 m", "height_above_msl_m": 0.257497, "vertical_accuracy": "0.070 m", "vertical_accuracy_m": 0.06965, "envelope_lower_m": 0.118197, "envelope_upper_m": 0.396797, "envelope_label": "+0.118 m to +0.397 m", "precision": "0.007 m", "offset_position": "58.58%", "is_below": false, "logger_offset_label": "", "connection_x": "56.29%", "connection_y": "49.84%", "connection_value_label": "+0.257 m", "connection_offset_top": "49.84%", "connection_offset_height": "0%", "connection_envelope_top": "45.30%", "connection_envelope_height": "9.09%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "MITIARO-20260610-HISEAS-390", "category": "waterline", "category_label": "Waterline", "label": "HS123: Te Rotonui shoreline", "site_label": "HS123: Te Rotonui", "note": "", "date_label": "2026-06-10 13:49", "height_above_msl": "+1.132 m", "height_above_msl_m": 1.132037, "vertical_accuracy": "1.591 m", "vertical_accuracy_m": 1.59125, "envelope_lower_m": -2.050463, "envelope_upper_m": 4.314537, "envelope_label": "-2.050 m to +4.315 m", "precision": "0.268 m", "offset_position": "87.73%", "is_below": false, "logger_offset_label": "", "connection_x": "66.86%", "connection_y": "21.31%", "connection_value_label": "+1.132 m", "connection_offset_top": "21.31%", "connection_offset_height": "0%", "connection_envelope_top": "0.00%", "connection_envelope_height": "100.00%", "has_envelope": true, "envelope_clipped_top": true, "envelope_clipped_bottom": true }, { "id": "MITIARO-20260609-HISEAS-364", "category": "waterline", "category_label": "Waterline", "label": "HS122: Teunu", "site_label": "HS122: Teunu", "note": "Very close to modern High tide", "date_label": "2026-06-09 16:12", "height_above_msl": "+1.300 m", "height_above_msl_m": 1.299557, "vertical_accuracy": "0.075 m", "vertical_accuracy_m": 0.07531, "envelope_lower_m": 1.148937, "envelope_upper_m": 1.450177, "envelope_label": "+1.149 m to +1.450 m", "precision": "0.005 m", "offset_position": "93.32%", "is_below": false, "logger_offset_label": "", "connection_x": "77.43%", "connection_y": "15.85%", "connection_value_label": "+1.300 m", "connection_offset_top": "15.85%", "connection_offset_height": "0%", "connection_envelope_top": "10.94%", "connection_envelope_height": "9.83%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "MITIARO-20260610-HISEAS-377", "category": "reef-flat", "category_label": "Reef flat", "label": "GCP1", "site_label": "GCP1", "note": "On raised reef flat", "date_label": "2026-06-10 12:10", "height_above_msl": "+0.546 m", "height_above_msl_m": 0.546077, "vertical_accuracy": "0.067 m", "vertical_accuracy_m": 0.0667, "envelope_lower_m": 0.412677, "envelope_upper_m": 0.679477, "envelope_label": "+0.413 m to +0.679 m", "precision": "0.002 m", "offset_position": "68.20%", "is_below": false, "logger_offset_label": "", "connection_x": "88.00%", "connection_y": "40.43%", "connection_value_label": "+0.546 m", "connection_offset_top": "40.43%", "connection_offset_height": "0%", "connection_envelope_top": "36.08%", "connection_envelope_height": "8.70%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false } ], "report_evidence_points": [ { "id": "MITIARO-20260609-HISEAS-341", "category": "control", "category_label": "Gauge GPS tie", "label": "Tide gauge Mitiaro", "site_label": "Tide gauge Mitiaro", "note": "1.910 m field offset to logger. Dock above tide gauge, where rope reaches dock surface", "date_label": "2026-06-09 09:06", "height_above_msl": "+0.965 m", "height_above_msl_m": 0.965117, "vertical_accuracy": "0.128 m", "vertical_accuracy_m": 0.12825, "envelope_lower_m": 0.708617, "envelope_upper_m": 1.221617, "envelope_label": "+0.709 m to +1.222 m", "precision": "0.005 m", "offset_position": "", "is_below": false, "logger_offset_label": "1.910 m field offset to logger", "logger_tie_m": -0.944883, "has_logger_offset": true, "sort_key": [ 0, "Tide gauge Mitiaro" ], "connection_x": "14.00%", "connection_y": "25.87%", "connection_value_label": "+0.965 m", "connection_offset_top": "25.87%", "connection_offset_height": "47.75%", "connection_envelope_top": "19.46%", "connection_envelope_height": "12.82%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false }, { "id": "MITIARO-20260611-HISEAS-404", "category": "waterline", "category_label": "Waterline", "label": "Waterline Chris\u2019s beach", "site_label": "Waterline Chris\u2019s beach", "note": "", "date_label": "2026-06-11 14:53", "height_above_msl": "-0.076 m", "height_above_msl_m": -0.075903, "vertical_accuracy": "0.064 m", "vertical_accuracy_m": 0.06408, "envelope_lower_m": -0.204063, "envelope_upper_m": 0.052257, "envelope_label": "-0.204 m to +0.052 m", "precision": "0.003 m", "offset_position": "47.47%", "is_below": true, "logger_offset_label": "", "connection_x": "51.00%", "connection_y": "51.90%", "connection_value_label": "-0.076 m", "connection_offset_top": "51.90%", "connection_offset_height": "0%", "connection_envelope_top": "48.69%", "connection_envelope_height": "6.41%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false, "report_label_position": "below" }, { "id": "MITIARO-20260610-HISEAS-377", "category": "reef-flat", "category_label": "Reef flat", "label": "GCP1", "site_label": "GCP1", "note": "On raised reef flat", "date_label": "2026-06-10 12:10", "height_above_msl": "+0.546 m", "height_above_msl_m": 0.546077, "vertical_accuracy": "0.067 m", "vertical_accuracy_m": 0.0667, "envelope_lower_m": 0.412677, "envelope_upper_m": 0.679477, "envelope_label": "+0.413 m to +0.679 m", "precision": "0.002 m", "offset_position": "68.20%", "is_below": false, "logger_offset_label": "", "connection_x": "88.00%", "connection_y": "36.35%", "connection_value_label": "+0.546 m", "connection_offset_top": "36.35%", "connection_offset_height": "0%", "connection_envelope_top": "33.01%", "connection_envelope_height": "6.67%", "has_envelope": true, "envelope_clipped_top": false, "envelope_clipped_bottom": false, "report_label_position": "middle" } ], "report_connection": { "axis_min_m": -2, "axis_max_m": 2, "axis_min_label": "-2.0 m", "axis_max_label": "+2.0 m", "datum_y": "50.00%", "logger_y": "72.99%", "logger_relative_m": -0.919698, "logger_relative_label": "-0.920 m", "point_count": 3 }, "evidence_filters": [ { "id": "all", "label": "All", "count": 8, "is_default": true }, { "id": "control", "label": "Gauge GPS tie", "count": 2, "is_default": false }, { "id": "waterline", "label": "Waterline", "count": 5, "is_default": false }, { "id": "reef-flat", "label": "Reef flat", "count": 1, "is_default": false } ], "evidence_count": 6, "connection": { "axis_min_m": -1.280191, "axis_max_m": 1.785485, "axis_min_label": "-1.280 m", "axis_max_label": "+1.785 m", "datum_y": "58.24%", "logger_y": "88.24%", "logger_relative_m": -0.919698, "logger_relative_label": "-0.920 m", "point_count": 8 }, "identity_image_url": "https://earth-history-uvic.s3.us-west-004.backblazeb2.com/web/photo-system/v1/thumb/2026/06/09/20260609-152018-eaa49f45f381-dd8384c7172e.jpg", "satellite_image_url": "https://server.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/export?bbox=-157.7458%2C-19.923%2C-157.6642%2C-19.787&bboxSR=4326&imageSR=4326&size=760%2C430&format=jpg&f=image" } ]