CON 1: Embedded Networked Sensing of Subsurface Water Quality Calibration, Fault Detection and Feedback Control

The objective of this work is to develop a modular subsurface environmental sensor node in support of aquatic chemistry observations in soils, sediments and groundwater. The resulting node is called as a soil pylon. Along with describing the pylon architecture, this work presents selected results pertaining to (1) a closed-loop system integrating pylon sensor feedback with process simulation and control algorithms, (2) scale up to large areas using soil geospatial properties, and (3) a protocol for pylon sensor fault filtering. In the former two cases, CENS soil pylons are being tested as a means of providing system feedback at a reclaimed water irrigation research plot in Palmdale, California. Another variation of the pylons was recently field-tested in Bangladesh in an effort to contribute to our understanding of the arsenic contamination problem there. The Palmdale pylons track soil moisture, temperature, and nitrate propagation in unsaturated soils.