Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.
J a n a e L . C s a v i n a
J o s h u a A . R o b e r t i
J e f f r e y T a y l o r
E S A A N N U A L M E E T I N G - A U ...
NEON: Overview
Nationwide ecological observatory fully funded by the National
Science Foundation that:
 Collects and prov...
NEON: Measurements
Inform biological, climate, carbon, water and
energy cycles/balances.
 Terrestrial Analysis
 Sensor: ...
NEON: Challenges
Maintaining consistency in measurement for:
 106 Sites
 20 domains
 Unique eco-climate
 3 terrestrial...
Calibration, Validation & Audit Laboratory:
NEON’s in-house consistency enforcer
 Calibrations:
 Performed at one lab fo...
Calibration, Validation & Audit Laboratory:
NEON’s in-house consistency enforcer
 Validations:
 Ensure manufacturer’s ca...
Calibration, Validation & Audit Laboratory:
NEON’s in-house consistency enforcer
 Audits:
 Ensure internal laboratory pe...
Maintaining consistency in measurement for:
 ~12,000 Terrestrial
and Aquatic sensors
 44 different types
of sensors
Cali...
Parameterize Inconsistencies with Uncertainty
Uncertainty: informing the quality of measurement
 Assessment Standard: JCG...
Parameterize Inconsistencies with Uncertainty
Uncertainty Assessment: Quantify this picture
DAQ:
Data
Acquisition
System
Truth & Trueness

Repeatability & Reproducibility

Combined and Expanded Uncertainty

Example: Temperature Sensor - Platinum Resistance
Thermometer (PRT) Calibration
 Utruth: SPRT = reference calibrated with...
Example: Temperature Sensor - Platinum Resistance
Thermometer (PRT) Calibration

• If 150 measurements taken n = 150
• Ov...
Example: Temperature Sensor - Platinum Resistance
Thermometer (PRT) Calibration

UDAQ= 0.0002 °C
Example: Temperature Sensor - Platinum Resistance
Thermometer (PRT) Calibration

Urepeatability = 0.0001 °C
Example: Temperature Sensor - Platinum Resistance
Thermometer (PRT) Calibration

Ureproducibility 2 = 0.0016 °C
Ureproduc...
Example: Temperature Sensor - Platinum Resistance
Thermometer (PRT) Calibration

UCombined= 0.0019 °C
UExpanded= 0.0040 °C
Learning from Uncertainty
 Annual calibration of all sensors
 Analyze sensor health
 Annual assessment of uncertainty
...
Learning from Uncertainty
 At the end of the day, uncertainty is an estimation…..
 " ... as far as the propositions of m...
The National Ecological Observatory Network is a project sponsored by the National
Science Foundation and managed under co...
Upcoming SlideShare
Loading in …5
×

Csavina: Uncertainty in an uncertain world: Using scientific judgment for evaluating uncertainty in measurement results.

1,097 views

Published on

Published in: Technology, Business
  • Be the first to comment

  • Be the first to like this

Csavina: Uncertainty in an uncertain world: Using scientific judgment for evaluating uncertainty in measurement results.

  1. 1. J a n a e L . C s a v i n a J o s h u a A . R o b e r t i J e f f r e y T a y l o r E S A A N N U A L M E E T I N G - A U G U S T 5 , 2 0 1 3 Uncertainty in an Uncertain World: Using scientific judgment for evaluating uncertainty in measurement
  2. 2. NEON: Overview Nationwide ecological observatory fully funded by the National Science Foundation that:  Collects and provides data on the drivers and responses of climate and ecological change  Serves as an experimental infrastructure and backbone for research and experiments  Develops and provides educational resources to engage communities in working with scientific data
  3. 3. NEON: Measurements Inform biological, climate, carbon, water and energy cycles/balances.  Terrestrial Analysis  Sensor: tower, soil  Sampling: biogeochemistry, biodiversity  Aquatic Analysis  Sensor: ground water, lakes, streams  Sampling: aquatic and sediment chemistry, biodiversity  Remote Sampling  Airborne: canopy characteristics, land cover, disturbance, etc.
  4. 4. NEON: Challenges Maintaining consistency in measurement for:  106 Sites  20 domains  Unique eco-climate  3 terrestrial/domain  3 aquatic/domain  30 years of observations
  5. 5. Calibration, Validation & Audit Laboratory: NEON’s in-house consistency enforcer  Calibrations:  Performed at one lab for all sensors providing consistency throughout network  Traceable to a nationally recognized standard (NIST, NREL, etc.)  All sensors annually calibrated
  6. 6. Calibration, Validation & Audit Laboratory: NEON’s in-house consistency enforcer  Validations:  Ensure manufacturer’s calibration  Sensor health  Consistency with other instruments
  7. 7. Calibration, Validation & Audit Laboratory: NEON’s in-house consistency enforcer  Audits:  Ensure internal laboratory performance  Ensure external laboratory performance  Field observation and collection consistency
  8. 8. Maintaining consistency in measurement for:  ~12,000 Terrestrial and Aquatic sensors  44 different types of sensors Calibration, Validation & Audit Laboratory: NEON’s in-house consistency enforcer
  9. 9. Parameterize Inconsistencies with Uncertainty Uncertainty: informing the quality of measurement  Assessment Standard: JCGM, 2008, Evaluation of measurement data – Guide to the expression of uncertainty in measurement (GUM), JCGM 100:2008.  Type A: evaluated by statistical methods. Experimental variance of independent observations which differ in value because of random variations.  Type B: evaluated by other means. Estimates obtained using available published knowledge such as manufacturer’s specs, calibration certificates, reference data from handbooks, etc.
  10. 10. Parameterize Inconsistencies with Uncertainty Uncertainty Assessment: Quantify this picture DAQ: Data Acquisition System
  11. 11. Truth & Trueness 
  12. 12. Repeatability & Reproducibility 
  13. 13. Combined and Expanded Uncertainty 
  14. 14. Example: Temperature Sensor - Platinum Resistance Thermometer (PRT) Calibration  Utruth: SPRT = reference calibrated with first principles (TPW, TPHg, MPGa)  Quantify by Type B analysis: Strouse, G.F., (2008) Standard Platinum Resistance Thermometer Calibrations from the Ar TP to the Ag FP, NIST Special Publication 250-81. Utruth= 0.000115 °C SPRT = Truth PRT = Measurement
  15. 15. Example: Temperature Sensor - Platinum Resistance Thermometer (PRT) Calibration  • If 150 measurements taken n = 150 • Over a range of temperatures Utrueness= 0.0004 °C
  16. 16. Example: Temperature Sensor - Platinum Resistance Thermometer (PRT) Calibration  UDAQ= 0.0002 °C
  17. 17. Example: Temperature Sensor - Platinum Resistance Thermometer (PRT) Calibration  Urepeatability = 0.0001 °C
  18. 18. Example: Temperature Sensor - Platinum Resistance Thermometer (PRT) Calibration  Ureproducibility 2 = 0.0016 °C Ureproducibility 1= 0.0007 °C Ureproducibility 1= 0.0005 °C
  19. 19. Example: Temperature Sensor - Platinum Resistance Thermometer (PRT) Calibration  UCombined= 0.0019 °C UExpanded= 0.0040 °C
  20. 20. Learning from Uncertainty  Annual calibration of all sensors  Analyze sensor health  Annual assessment of uncertainty  Analyze drift of the sensors  Uncertainty used for quality checks to determine sensor performance  Identify non-conforming sensors
  21. 21. Learning from Uncertainty  At the end of the day, uncertainty is an estimation…..  " ... as far as the propositions of mathematics refer to reality, they are not certain; and as far as they are certain, they do not refer to reality." Albert Einstein, Geometry and Experience, Lecture before the Prussian Academy of Sciences, January 27, 1921
  22. 22. The National Ecological Observatory Network is a project sponsored by the National Science Foundation and managed under cooperative agreement by NEON Inc. www.neoninc.org jcsavina@neoninc.org

×