Sensor Calibration Automation Demonstration Presenters: Barbara Benson and David Balsiger (University of Wisconsin) Collaborators: Laurence Choi, Yu Hen Hu, Paul Hanson, Tim Kratz, Tim Meinke (University of Wisconsin); Ken Chiu (SUNY-Binghamton)

Motivation Example from current practice: –Sensor calibration: Due to sensor drift, the Greenspan dissolved oxygen (DO) sensor requires frequent (once every two weeks) calibration services. –Sensor data correction: After the DO sensor is calibrated, the observed data since last calibration need to be adjusted accordingly.

Problem: –Both tasks are performed manually –Labor-intensive process –Does not scale-up well Solution  Automation –Steps toward automation Web interface for technician, information manager Calibration agent integrated into data flow

New Calibration Method Old Method –The Greenspan is manually pulled out of the water and rested for an hour to allow it to stabilize. –The time, air temperature and barometric pressure are recorded and a “correction factor” is estimated manually. Proposed New Method –A calibrated DO sensor is placed manually next to the existing un-calibrated DO sensor in the water and records data in parallel during “calibration”. –The data recorded from both sensors are entered into a calibration program to calculate “correction factor” automatically. Potential Benefit –Shorter calibration time –Semi-automated procedure

“Calibration Period” Data

Steps Development of computer program modules for the algorithms for calculating the “correction factor” and correcting data Design of user interface for technician or information manager to execute algorithms

“Calibration” Algorithms Calculating correction constant Correct un-calibrated data using estimated correction factor

Future steps Extend the program to access the Oracle database for data retrieval and updating Integrate web interface with the portal Develop calibration agent(s) –Sensor service manager –Calibration event manager –Data calibration manager

Growing the Sensor Network: Agents and Remote Code Deployment Collaboration with computer scientists at UCSD, Indiana, and SUNY-Binghamton and computer engineering colleague at UW-Madison Automated Scaling and Data Processing in a Network of Sensors NSF NEON Grant: Addressing the Scaling Challenge Calibration Agent

Calibration Agent(s) Will detect calibration event Handle sensors being swapped Retrieve or capture “calibration” data Calculate the correction factor Retrieve data to be corrected Correct data and load corrected data to the database Write event data to calibration log in the database

A Work In Progress …