AN INEXPENSIVE AUTOMATED LAGRANGIAN WATER-QUALITY ASSESSMENT SYSTEM (ALWAS)+ FOR CALIBRATION AND VALIDATION OF REMOTE SENSING OBSERVATIONS*

摘要

The Automated Lagrangian Water-Quality Assessment System (ALWAS) is an inexpensive, free-floating, water quality measuring and watershed evaluation system. The system can also be used to provide sea truth for satellite or aircraft validation. It is capable of making a wide range of measurements rapidly and simply, storing the results for later retrieval and analysis. The system consists of the buoy, water quality and parameter sensors, a microprocessor and recording device, geographic information system (GIS) interface software, and a decision support system (DSS) that generates water quality maps based on the measurements. The water quality sensors include: GPS for time, location and speed, temperature, depth, conductivity and calculated salinity, pH, dissolved oxygen, turbidity, chlorophyll-A, nitrates, and barometric pressure (needed for calibration of the dissolved oxygen measurement).