Advanced instruments for field deployment with laboratory capabilities

AirPhoton Inc. is a small Maryland-based company which opened in 2012. We design and manufacture instruments to measure airborne particulates and trace gases. Our goal is to provide highly capable instruments that can be used by those who study human exposure to pollution and to provide data to understand aerosol effects on climate change. As scientists who have been working with remote sensing and in-situ instruments since the 90’s, we understand the needs of other scientists and strive to maximize the information content provided by our instruments. We manufacture optics-based instruments for real time measurements of particulates and filter based instruments for later restrospective analysis of particulates & trace gases. Our instruments have been deployed globally by the SPARTAN Network, NASA’s MAIA mission and a host of research institutes.

In the summer of 2022 AirPhoton merged with GRASP-SAS, forming GRASP-Earth. GRASP-SAS has developed a data platform which is used to create aerosol, cloud and surface property data products for satellite sensors. It is widely used by several space agencies in Europe and operational product for missions such as Sentinel-4, CO2M or 3MI. Our goal for GRASP-Earth is to push the boundaries of instrument capabilities by integrating space and ground observations along with models to advance our monitoring and understanding of Earth’s atmosphere. We use GRASP with our in-situ optical instruments to allow us to maximize their information content and to create advanced products.

We are using GRASP in innovative new ways to synergistically combine data from various instruments to create data products which go beyond current offerings. These include: In-situ instruments with satellite data; satellite data from multiple platforms; and data from different types of in-situ instruments. Our instruments have unique features that our competitors do not offer and which you will see on the following section. If you have a question or a suggestion for an application or a new instrument please reach out. Innovation is a collaborative process that is enriched by many minds.

IMAP 100

PI Neph+GRASP synergy for a better instrument’s understanding

The PI-Neph (Polarized Imaging Nephelometer) is an innovative instrument developed by AirPhoton team. It features a wide field-of-view camera within a closed chamber to detect scattered light from aerosol particles. This multi-wavelength nephelometer provides accurate measurements of the P11 (phase function) and -P12/P11 (polarized phase function) from ambient aerosol particles at wavelengths of 405nm, 515nm, and 660nm, spanning an angular range of 5-175 degrees with high angular resolution (1 degree). Advanced observations from the PI-Neph have been integrated into the GRASP algorithm for:

1. Synthetic tests on typical aerosol models, including dust, oceanic, urban, and biomass burning aerosols, with the option to introduce random noise into the measurements. The synthetic tests enable clients and scientists to explore the potential and capabilities of the measurements.

2. Real measurements collected at ground stations, such as the University of Granada in Spain, during various pollution episodes including dust and biomass burning events.

The results have demonstrated the great capability of the PI-Neph/GRASP to retrieve aerosol microphysical properties with high accuracy—such as aerosol size distribution, complex refractive index, and sphericity—while achieving good fit with the measurements with low retrieval residuals.

Our capabilities include

In-situ instrumentation

We develop ground-based in-situ instrumentation made by scientists for scientists. Our collection includes instrumentation such as Nephelometers and Filter Stations. These tools ensure precise and reliable measurements.

Laboratory instrumentation

Our instruments are suitable for laboratory use as well as in-field deployment. Our Polar Imaging Nephelometer is a high-grade instrument intended for laboratory or aircraft use, providing excellent performance.

Custom instrumentation

Our team has skills and experience in developing custom instrumentation and/or measurement solutions for difficult problems. In this regard, we can also provide consulting and training services to meet specific needs.

Aircraft instrumentation

Many of our instruments can be modified for deployment in aircraft. Such was the example of the AirPhoton FIREFly, a system for forest fire identifications. These modifications enhance the instruments versatility.

Satellite products and services

We have developed and launched the GAPMAP instrument, a cubesat for spaceborne particulate measurements. Our team is currently working on an instrument for greenhouse gas detection to expand our capabilities.

The Team

Richard Kleidman | CEO

Richard Kleidman, AirPhoton’s CEO, co-developed NASA’s international training program. With 30 years of experience in teaching, training, and communicating science and technology, he also boasts 25 years in algorithm development for satellite retrievals.

Lorraine Remer | CSO

Lorraine Remer, CSO, led NASA’s aerosol product development team from 1998-2012. With 30 years of experience in Remote Sensing and satellite-based science and management, she is also a Fellow of the American Geophysical Union.

Vanderlei Martins | CTO

Vanderlei Martins, CTO, is Director of the UMBC Earth Space Institute and Professor of Physics. He led the HARP 3U cubesat launch in 2019 and is the principal investigator for the HARP2 polarimeter on NASA’s PACE mission.

John Hall | COO

John Hall, AirPhoton’s COO, holds a Bachelor of Science in Mechanical Engineering. With 14 years of experience in engineering design and manufacturing, he is also a certified AERMOD Gaussian air dispersion modeler.

Our instruments provide

Real-time particulate measurements

AirPhoton nephelometers provide real-time measurements of airborne particulates using light scattering to assess aerosols' size and concentration with high sensitivity. These instruments feature advanced models like IN101T, IN102, or IN102Ex, ensuring precise and reliable data collection. The IMAP measures polarized scattered light at multiple angles and wavelengths, allowing rapid determination of particle size distribution across PM1 to PM10. Additionally, the Polar Imaging Nephelometer offers comprehensive particle characterization, including size distribution and complex refractive index. This makes it essential for particulate analysis in various applications, such as environmental monitoring, industrial hygiene, and research studies, enhancing understanding of quality.

Sampling stations measurements

AirPhoton has developed filter sampling station instruments with several unique features for retrospective analysis of particulate matter. The Aeroexplorer sampling station comes in single and dual inlet models, allowing sequential or simultaneous collection of particulates at size cuts between PM2.5 and PM10. Alongside our nephelometers' real-time measurements, this provides a full picture of particulates and trace gases for air quality. Recently, we developed a station for trace gas collection, sampling gases like ammonia, nitrates, and VOCs. We have also added the capability to sample by wind direction as well as time. Operating at low flow rates and supported by solar or battery power, it is ideal for remote or environmentally sensitive areas, aiding in source apportionment and fence-line monitoring.

Discover AirPhoton

Optical Instruments

Sampling Stations






Clean Air Reference

Advanced Optical Instruments


PI Neph


Aeroexplorer particulate filter sampling

Filter cartridges

Aeroexplorer trace gas Sampling


Catalogue 2024

AirPhoton Ltd. is a Maryland-based company part of GRASP Earth. For any legal information, please contact | © GRASP SAS, all rights reserved, 2024