One recently finished project was performed by the University of Wisconsin and has comprised the depolyment of two data buoys which are both furnished with a multifunctional Lufft WS501-UMB. These weather sensors measure ambient temperature, relative humidity, air pressure, wind direction and speed as well as solar radiation detection with the help of a Kipp & Zonen pyranometer. The data is transported to the National Data Buoy Center, Great Lakes Observing System and the University of Michigan’s Ocean Engineering Lab via cellular telemetry. The buoys themselves as well as an included data loggers originate from NexSens. Some solar powered marine lights help to keep the installations visible in the darkness. Further attached sensors are a thermistor string for high precision underwater temperature measurement and a water level sensor – both from NextSens as well. They are deployed in Lake Michigan – one near Milwaukee, WI and the other one near Green Bay, WI.
Another similar buoy launch was finished in April 2015. This project was performed by the Iowa Lakeside Laboratory and took place in the same lake region (West Okoboji Lake). It was added to the GLEON (Global Lake Ecological Observatory Network). This refers to a global association which shares and interprets sensor data in order to understand, predict and communicate the lakes’ behavior in a changing global environment.
The Lakeside Lab has offered courses and research opportunities for students interested in studying West Okoboji and other lakes nearby for more than one century already. They have collected diatoms and algae, took Secchi disk measurements or tracked dissolved oxygen levels. Therefore the idea to launch a measurement buoy was obvious, as it was clear that everybody just would take advantages from it: the lab and researchers from all over the world benefit from the data, boaters and fishermen from the issued safety level and visitors from the delivered weather and temperature information.
The project was funded by State Iowa Hygienic Lab and the University of Iowa Research and Economic Development Group and lasted only 10 months until the data delivery ran. It consists of a NexSens CB-450 Data Buoy and a iSIC-CB Data Logger including a cellular telemetry unit for data transmission. On top a Lufft WS600 all-in-one weather sensor measures temperature, humidity, barometric pressure, wind speed and direction and precipitation. Also in this solution marine lights ensure its night visibility. At the buoy’s bottom side YSI EXO2 multi-parameter water quality sonde detects water temperature, conductivity, pH and dissolved oxygen levels. A carbon dioxide transmitter with special membrane recognizes CO2 levels underwater. For the data display a private WQData LIVE Web Datacenter was introduced and all data can be watched comfortably online – even on smartphones with the help of a related app.
It is planned to extend the swimming equipment with a DO (dissolved oxygen) string, which will reach into a water depth of 30 meters, and is in use for measurement buoys very seldom so far.