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 aninexpensive, 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 iscapable of making a wide range of measurements rapidly and simply, storing the resultsfor later retrieval and analysis. The system consists of the buoy, water quality andparameter sensors, a microprocessor and recording device, geographic informationsystem (GIS) interface software, and a decision support system (DSS) that generateswater quality maps based on the measurements. The water quality sensors include: GPSfor time, location and speed, temperature, depth, conductivity and calculated salinity, pH,dissolved oxygen, turbidity, chlorophyll-A, nitrates, and barometric pressure (needed forcalibration of the dissolved oxygen measurement).