{
  "schema": "SOVRIENT_AIS_LOCAL_SOURCE_MANIFEST_V1",
  "generated_utc": "2026-04-04T17:48:00Z",
  "artifact_role": "bounded_local_slice",
  "slice_id": "ais_hampton_roads_2025-09-15_bbox",
  "area_name": "Hampton Roads / lower Chesapeake approaches",
  "time_window": {
    "start_utc": "2025-09-15T00:00:00Z",
    "end_utc": "2025-09-15T23:59:59Z"
  },
  "bounding_box": {
    "min_lon": -76.8,
    "max_lon": -75.3,
    "min_lat": 36.7,
    "max_lat": 37.35,
    "bbox_role": "analyst_defined_reproducible_clip"
  },
  "source": {
    "provider": "NOAA Office for Coastal Management / Marine Cadastre",
    "dataset_name": "ais-2025-09-15.csv.zst",
    "dataset_class": "point_data",
    "source_url": "https://coast.noaa.gov/htdata/CMSP/AISDataHandler/2025/ais-2025-09-15.csv.zst",
    "source_ref": "noaa_csv2025:ais-2025-09-15.csv.zst",
    "data_as_of": "2026-04-04",
    "downloaded_utc": "2026-04-04T17:48:00Z",
    "land_based_open_ais": true,
    "live": false,
    "satellite": false
  },
  "files": {
    "raw_input": {
      "name": "ais-2025-09-15.csv.zst",
      "sha256": "cd73d654f60b2df4dda3edb75c9eebae362bd553f8d25d74f8e0ebce125ce37d",
      "size_bytes": 239907155,
      "official_url": "https://coast.noaa.gov/htdata/CMSP/AISDataHandler/2025/ais-2025-09-15.csv.zst"
    },
    "clipped_output": {
      "name": "maritime_ais_hampton_roads_2025-09-15_bbox.csv.gz",
      "sha256": "bca5e4f4eff96daa3a46cc827576363d411fe17beda0942dc20a5af7df42dd0b",
      "size_bytes": 5130421,
      "public_url": "https://www.sovrient.com/data/maritime_ais_hampton_roads_2025-09-15_bbox.csv.gz",
      "public_sha256_url": "https://www.sovrient.com/data/maritime_ais_hampton_roads_2025-09-15_bbox.csv.gz.sha256"
    }
  },
  "fields": [
    "mmsi",
    "base_date_time",
    "longitude",
    "latitude",
    "sog",
    "cog",
    "heading",
    "vessel_name",
    "imo",
    "call_sign",
    "vessel_type",
    "status",
    "length",
    "width",
    "draft",
    "cargo",
    "transceiver"
  ],
  "stats": {
    "observation_count": 201376,
    "unique_mmsi_count": 463,
    "first_timestamp_utc": "2025-09-15 00:00:00",
    "last_timestamp_utc": "2025-09-15 23:59:59",
    "top_vessel_types": [
      {"value": "52", "count": 48576},
      {"value": "37", "count": 32406},
      {"value": "31", "count": 21414},
      {"value": "70", "count": 18914},
      {"value": "36", "count": 10695},
      {"value": "30", "count": 9320},
      {"value": "33", "count": 6838},
      {"value": "90", "count": 6642},
      {"value": "60", "count": 5956},
      {"value": "null", "count": 4697}
    ],
    "top_transceivers": [
      {"value": "A", "count": 155373},
      {"value": "B", "count": 46003}
    ],
    "representative_mmsi": {
      "mmsi": "368231430",
      "observation_count": 1230,
      "vessel_name": "DELAWARE"
    }
  },
  "sample_rows": [
    {
      "mmsi": 368145530,
      "base_date_time": "2025-09-15 00:00:02",
      "longitude": -76.34508,
      "latitude": 36.85916,
      "sog": 0.0,
      "cog": 287.4,
      "heading": 336.0,
      "vessel_name": "ANNABELLE MILLER",
      "imo": "IMO9575113",
      "call_sign": "WDL5902",
      "vessel_type": 90.0,
      "status": 5.0,
      "length": 54.0,
      "width": 14.0,
      "draft": null,
      "cargo": null,
      "transceiver": "A"
    },
    {
      "mmsi": 367612310,
      "base_date_time": "2025-09-15 00:00:04",
      "longitude": -75.45758,
      "latitude": 36.88399,
      "sog": 0.7,
      "cog": 37.6,
      "heading": 74.0,
      "vessel_name": "HOS BLACK FOOT",
      "imo": "IMO9647693",
      "call_sign": "WDH3920",
      "vessel_type": 70.0,
      "status": 0.0,
      "length": 100.0,
      "width": 15.0,
      "draft": 5.2,
      "cargo": 70.0,
      "transceiver": "A"
    },
    {
      "mmsi": 368336010,
      "base_date_time": "2025-09-15 00:00:02",
      "longitude": -76.34019,
      "latitude": 36.92452,
      "sog": 10.1,
      "cog": 182.3,
      "heading": 185.0,
      "vessel_name": "WINDEA COURAGEOUS",
      "imo": null,
      "call_sign": "WDP2409",
      "vessel_type": 40.0,
      "status": 0.0,
      "length": 31.0,
      "width": 10.0,
      "draft": null,
      "cargo": 40.0,
      "transceiver": "A"
    },
    {
      "mmsi": 367680370,
      "base_date_time": "2025-09-15 00:00:01",
      "longitude": -76.28606,
      "latitude": 36.80842,
      "sog": 0.0,
      "cog": 270.4,
      "heading": null,
      "vessel_name": "COASTAL TRADER",
      "imo": null,
      "call_sign": "WDI2655",
      "vessel_type": 31.0,
      "status": null,
      "length": 23.0,
      "width": 7.0,
      "draft": 2.5,
      "cargo": 90.0,
      "transceiver": "A"
    },
    {
      "mmsi": 538008779,
      "base_date_time": "2025-09-15 00:00:00",
      "longitude": -76.16743,
      "latitude": 36.98833,
      "sog": 12.5,
      "cog": 107.7,
      "heading": 109.0,
      "vessel_name": "LIVADI",
      "imo": "IMO9522946",
      "call_sign": "V7A2750",
      "vessel_type": 79.0,
      "status": 0.0,
      "length": 179.0,
      "width": 28.0,
      "draft": 7.5,
      "cargo": 79.0,
      "transceiver": "A"
    }
  ],
  "what_this_does_not_prove": [
    "that the slice is a live AIS feed",
    "that the slice has global or offshore-complete coverage",
    "that a missing observation proves vessel absence",
    "that the slice by itself proves spoofing or malicious behavior"
  ]
}