Meet
our Webinars
We regularly host webinars to share our latest advancements in particulate monitoring and air quality research. These sessions cover topics such as AirPhoton instruments, urban-scale pollution modeling, and the the use of GRASP open-source algorithm. Our webinars are designed for scientists, researchers, and professionals looking to stay updated on new technologies and methodologies on particulate monitoring.
New GRASP aerosol dashbord: an all-in-tool for particle characterization
IN Series | Tue Nov 24th, Wed Nov 25th | Mr. Richard Kleidman
How can we translate nephelometer measurements into physically consistent aerosol properties? In the following webinar, Mr. Richard Kleidman will introduce the GRASP Aerosol Dashboard, a new platform that converts AirPhoton Integrating and Polar Nephelometer data into scientifically meaningful products. The dashboard automatically runs the GRASP inversion to deliver fine and coarse mode size distributions (with mean radii), PM₂.₅ mass in wet and dry conditions, and real-time total and backscatter. The session will also highlight the instrument features that enable robust GRASP retrievals and explore how these products can be paired with other sensors. While the focus is on Integrating nephelometers, the same dashboard supports IMAP and Mini-IMAP instruments. Mr. Richard Kleidman will open with the fundamentals of interpreting scattering measurements and GRASP-based methods.
Polar Nephelometers advanced capabilities for characterizing Particulate Pollution
Mini-IMAP | Tue 16th July, 2025 | Mr. Richard Kleidman
Polar nephelometers open new possibilities for understanding particulate pollution, offering capabilities beyond traditional nephelometers, particle counters, or low-cost sensors. Interestingly, “polar” refers not to measuring polarization but to the arrangement of detectors around a central chamber. This webinar explores how polar nephelometry compares with classic methods, using the AirPhoton Mini-IMAP instrument as a reference. Mini-IMAP delivers advanced particulate characterization and reliable performance, often comparable to that of larger and more costly systems. The webinar explains what types of aerosol information can be retrieved, how polarization measurements enhance that information, and where this fits in broader Earth observation workflows—bridging surface data with satellite perspectives through examples such as size distributions and AERONET comparisons.
Understanding Particulate Pollution Measurements with Nephelometers
IN series | Wed 8th May, 2025 | Mr. Richard Kleidman
Nephelometers have played a central role in air quality research and regulatory monitoring since the 1960s. They are also core instruments in the ACTRIS (Aerosol, Clouds, and Trace Gases Research Infrastructure) network, providing high-quality aerosol measurements. Despite their long use, interpreting nephelometer data remains challenging. This webinar will review the fundamentals of how nephelometers measure particulate matter, clarify what insights this data can and cannot provide, and discuss key factors affecting measurement capabilities and data quality. We will use the AirPhoton IN101 nephelometer—approved for use in ACTRIS and widely deployed by the SPARTAN network—as a reference to explain basic measurement principles. We’ll then introduce the IN102 model, highlighting how its hardware upgrades and integration with GRASP software allow enhanced particle characterization, including estimates of size distribution and dry particulate mass.
New directions in particulate measurements using polarization from ground and satelite
IMAP | Tue 25th Mar, 2025 | Dr. Barbara Bertozzi (PSI)
What can we learn from polarization measurements? The Paul Scherrer Institute’s Luminous field campaign in Grenada Spain observed several dust events and featured the first deployment of the IMAP 100 ground instrument. The IMAP100 characterizes particles using polarization as well as using multiple wavelengths, angles and size cuts. Dr. Barbara Bartozzi of PSI will discuss what they learned during Luminous using the IMAP in conjunction with several other instruments. She will dicuss instrument performance and future prospects for using polarization in conjunction with satellite data. Mr. Richard Kleidman of AirPhoton will provide an introduction that discusses the basics of particulate observations using polarization,multiple wavelengths, and angular information and the IMAP instrument.
Determining PM2.5 mass with Nephelometer optical measurements
IN series | Tue 3rd Sept, 2024; Wed 4th Sept, 2024 | Dr. Chong Li
Typically nephelometers use optical measurements to provide information about bulk particulate properties such as size and amount. AirPhoton nephelometers offer features that allow us to use GRASP to pull out additional information from the raw measurements such as size distribution and particulate mass. The SPARTAN network deploys our nephelometers around the globe alongside our filter based particle sampling stations. This provides us a unique data set to compare real time optical measurements and PM 2.5 retrievals with gravimetric based PM 2.5 measurements in a variety of environments and conditions. In our first webinar Dr. Chong Li will present the results of the work she has been doing with GRASP and machine learning to obtain PM2.5 dry mass estimates from AirPhoton nephelometer measurements deployed by the SPARTAN network.
Modeling Street Level PM Dispersal
Modelling | Tue 8th Oct, 2024; Wed 9th Oct, 2024 | Dr. Konstantin Kuznetsov
The use of satellite data for urban pollution monitoring has been studied for over 25 years. The most serious limitations are the lack of spatially high-resolution data and the inability to obtain vertical resolution to understand exposure at ground level. A new generation of higher resolution satellite data for air quality monitoring as well as several techniques for improving ground level exposure estimates are under development. We are applying a new approach which combines satellite data with Computational Fluid Dynamics (CFD) modeling to retrieve road emissions and pollution concentrations at a detailed 1-meter resolution. This method developed by Dr Konstantin Kuznetsov simulates pollution dispersion in urban environments, accounting for factors like buildings, roads, and vegetation.