Tide monitoring, alerting, and prediction

Forecasting tide levels is important to navigation and government agencies like NOAA provide forecasted tide levels for many ports.

The most accurate tidal forecasts are based on local measurements taken at NOAA “Harmonic Stations”.  NOAA also provides tidal predictions for subordinate stations that do not have local tide gauges or tidal harmonic constants available.  These stations are typically less accurate.  Popponesset Bay is a NOAA subordinate station where NOAA does not have a tide gauge.

Tidal measurements have been taken in Popponesset Bay using a personal tide gauge and the predictions from these data are available as tide tables and charts on this web site.  Real-time tide levels are also available and it is very useful for boaters wishing to avoid getting stuck to see the effect of wind on tide levels.  Strong wind from certain directions can increase or decrease the tide levels by up to about 2 feet and can also delay or advance the timing of the high or low tide.

The technology behind this website uses a cellular tide gauge based on the Particle Electron cellular module and a Maxbotix range sensor. Range data is sent to the IoT platform ThingSpeak every minute. MATLAB software is used with the “UTide” harmonic tidal prediction package to forecast the tide and to generate the Tide Table and low-tide calendar. The effect of wind on the forecasted tide levels is predicted using a neural network designed using MATLAB. A ThingSpeak MATLAB visualization generates the Experimental Tide Forecast with Wind Surge using MATLAB code that includes the neural network.

Read the article “Developing an IoT Analytics System with MATLAB, Machine Learning, and ThingSpeak” for a detailed explanation of how the tide and wind-surge forecasting works.