Picton Harbours maintains three tide stations in the Marlborough Sounds. Each has a pressure sensor and a radar sensor. Measurements are taken every ten minutes and reported by AIS broadcast and via cellular data to Marlborough’s data distribution platform.
Marlborough managed tide stations are located at:
Okukari Bay (-41.201612°, 174.311423°)
Motuara Island (-41.093883°, 174.271459°)
Te Weka (-41.249400°, 174.192815°)
Stations transmit AIS messages 21 and 8 once every six minutes on each channel, offset by three minutes. Message 21 reports the station name and coordinates. Message 8 reports a composite tide height that considers inputs from both pressure and radar sensors.
JSON Messages
More complete data is available via JSON messages, available on request. Message format is:
{
"sensor_id": "pcn.motuara.tidestation.1",
"timestamp": "2021-11-30T17:10:00Z",
"measurement_id": "86989b17-9984-0098-7feb-b20f23e60dfc",
"tide_height": 1.123, "tide_height_sd": 0.015,
"measurement_type": "pressure_sensor",
"pressure_measure": 2.262, "pressure_measure_sd": 0.015,
"radar_range": null, "radar_level": null,
"radar_level_sd": null,
"radar_status": "offline",
"radar_signal_strength": null,
"ais_water_level": null,
"ais_timestamp": null
}