Preserving the Preserving the Comparability of Comparability of

Sensor DataSensor DataA Possible Use CaseA Possible Use Case

Charles S. Spooner, US EPACharles S. Spooner, US EPAESIP 2010 Winter MeetingESIP 2010 Winter Meeting

Washington, DCWashington, DC

Water Quality DataWater Quality Data►Overwhelmingly an investment by Overwhelmingly an investment by

public agenciespublic agencies►Our goal is to preserve that investment Our goal is to preserve that investment

for future use recognizing that:for future use recognizing that: the value of good data increases over timethe value of good data increases over time the value of undocumented data the value of undocumented data

decreases quicklydecreases quickly

Data ComparabilityData Comparability► Reliability and confidence in long-term, Reliability and confidence in long-term,

broad scale datasets is directly related to broad scale datasets is directly related to maintenance of data quality, and the ability maintenance of data quality, and the ability of the scientific community to summarize of the scientific community to summarize and communicate that confidence (Costansa and communicate that confidence (Costansa et al., 1992; Edwards, 2004)et al., 1992; Edwards, 2004)

► Comparability is defined by EPA’s Quality Comparability is defined by EPA’s Quality Assurance Division as “the confidence that Assurance Division as “the confidence that two data sets can contribute to a common two data sets can contribute to a common analysis and interpolation” (USEPA, 2006). analysis and interpolation” (USEPA, 2006).

Comparable Water Quality Comparable Water Quality DataData

►Minimum Metadata to travel with the dataMinimum Metadata to travel with the data The standard data elements of the Advisory The standard data elements of the Advisory

Committee on Water Information (ACWI)Committee on Water Information (ACWI)►Chemical & Microbiological AnalytesChemical & Microbiological Analytes►ToxicityToxicity►Population and Community Level Analytes Population and Community Level Analytes ►Physical Habitat CharacterizationsPhysical Habitat Characterizations

EPA Environmental Sampling, Analysis and EPA Environmental Sampling, Analysis and Results Standards (ESAR)Results Standards (ESAR)

EPA/USGS Water Quality Exchange Schema EPA/USGS Water Quality Exchange Schema (WQX)(WQX)

Sensors: Defining Water Quality Sensors: Defining Water Quality in the Futurein the Future

►Continuous data – More relevant Continuous data – More relevant ►Real-time data - Immediate accessReal-time data - Immediate access►Better/Different coverageBetter/Different coverage

More relatable to watershed and More relatable to watershed and weather dataweather data

Comparable Sensor Water Comparable Sensor Water Quality DataQuality Data

►Continuous data, not discrete samplesContinuous data, not discrete samples►Current practicesCurrent practices

Influenced by non-standard vendor Influenced by non-standard vendor softwaresoftware

Applied in research settingsApplied in research settings Being driven by a search for a language Being driven by a search for a language

that can promote data transmissionthat can promote data transmission►Water MLWater ML►Sensor MLSensor ML

The Basic IssuesThe Basic Issues►Will These MLs Protect the Will These MLs Protect the

Comparability of Sensor Data ?Comparability of Sensor Data ?►How will the data be stored?How will the data be stored?

Examples of Sensor Examples of Sensor DeploymentsDeployments

These examples are from the Chesapeake Bay whereThis use case might easily be focused

DataFlow Aboard ShipDataFlow Aboard Ship

Automous Underwater Automous Underwater VehicleVehicle

GlidersGliders

GlidersGliders

Vertical ProfilersVertical Profilers

Proposed Use CaseProposed Use Case► Compare metadata fields forCompare metadata fields for

1.1. Existing WQ sensors in different settingsExisting WQ sensors in different settings► Vertical profilersVertical profilers► Data Flow systemsData Flow systems► Autonomous Underwater VehiclesAutonomous Underwater Vehicles

2.2. The WQX SchemaThe WQX Schema3.3. Sensor Workgroup Data ElementsSensor Workgroup Data Elements

– AQ, Calibration, Operator CompetenceAQ, Calibration, Operator Competence4.4. Water MLWater ML5.5. Sensor MLSensor ML

Use Case ResultsUse Case Results

ProfilersDataFLowAUVsWQXSWGWater MLSensor ML

When HowWho What Where Why