Agenda

CT6 – Sensors (2.5h) 02/10 09:00 – 11:30

• 09:00 -- 09:15 Feedback CT6 work plan, general idea and concept of inter-comparisonexercise on sensor/model integration

• 09:15 -- 09:30 Development of a benchmark / test set for PM2.5 (Sjoerd van Ratingen) • 09:30 -- 09:45 Ideas for a benchmark / test set for NO2 (Stijn Janssen)• 09:45 -- 10:00 Sensor.Community network, lessons learnt (Lukas Mocek )• 10:00 -- 10:20 Reflections about user-needs and potential output of the benchmarks

Vera Rodrigues, Stig Hellebust, Teodora Polimerova• 10:20 -- 11:15 General discussion about setup of the benchmark(s), goals, …• 11:15 -- 11:30 Next steps

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Questions to the public

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Before we begin …

• Under the right conditions, sensors can already provide useful near real-time information regarding the air quality.

• Especially during special occasions (New Year) and incidents the uncertainty of sensor is not so important.

• When the concentrations are high enough you don’t really need calibration or complex processing.

• The main challenge is using sensors under average (‘normal’) conditions when relatively small concentration differences may be important.

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Before we begin …

FAIRMODE | CT6 | October 02, 2020

www.youtube.com/watch?v=dJveRLMRaiA https://twitter.com/samenmeten/status/1289215018274234368

Effects from Easter 2019 fires measured in the Netherlands during the week-end.

Cloud of smoke from a large fire (car tires) in very stable meteo conditions. Legend: red = 40 ug/m3 PM10.The data covers some 7 hours and 100 km.

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Feedback CT6 work plan

• Draft CT6 work plan was distributed on May, 29, 2020.• Received 7 reactions.

- Definition of low-cost.- Interest in tests using synthetic data.- Some reactions focus on quality of individual sensors.- Some people are sceptical about sensor data.- Several offers for participation in benchmark tests.- Several offers of sensor data.

• The feedback was used to develop an idea for benchmark tests.

• Presentation + discussion of the benchmark ideas.

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General idea benchmarks

• Define 1-3 data sets with artificial/synthetic sensor data.• Case PM2.5: 500-1000 low-cost sensors distributed in a “large region”.• Case NO2: 25-50 relatively low-cost sensors distributed in a “city”.• The artificial/synthetic sensor data can be more/less noisy.• The artificial/synthetic concentrations will be provided for 4-8 weeks.

• Objectives for the benchmark are to develop/test/compare methods: … to select which sensors to use for every hour;… to obtain best estimates for “calibrated”/ “corrected” sensor data.

… to combine cleaned/calibrated sensor data with other info/model data à Data Fusion and/or Data Assimilation.

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Selection/ 1a.Calibration 1b.

Combine 2.data

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User-needs

• Reflections about user-needs and potential output of the benchmarks.• What are important questions that organisations would like to see addressed

in the benchmarks?• How to address both the proof-of-principle of sensors (what are they worth?)

as well as the use of more complex processing of the results (Data Fusion/Assimilation).

• Availability of data that is suitable for use in tests by others?

• Different reflections: - Vera Rodrigues, - Stig Hellebust, - Teodora Polimerova,- The audience

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Development of a benchmark / test set for PM2.5

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Ideas for a benchmark / test set for NO2

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Sensor.Community network, lessons learnt

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Reflections about user-needs and potential output

General discussion

• To be discussed:q Comments/suggestions regarding the proposed benchmarks?

q Input for the discussion on NO2?

q Suggestions regarding use of Sensor.Community data.

q General ideas about user needs.

q Way forward / planning …

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Questions to the public

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Next steps

• Activities and planning CT6 for the period now – June 2021.- 2020 Oct-Dec : Further discussion/definition of benchmarks.- 2021 Feb(?) : Report FAIRMODE plenary meeting- 2021 Feb-Mar : Hackathon (@RIVM or web).- 2021 Jan-Sep : Work on benchmarks.- 2021 Fall : 1st (technical) report FAIRMODE technical meeting

• Further suggestions?

• Do you want to participate?à Please let us know!

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Thank You !

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