Arctic Research of the Composition of the Troposphere from Aircraft and Satellites

The Research Scanning Polarimeter (RSP) is an airborne, passive polarimeter developed by SpecTIR Corporation. It measures total radiance and linear polarization across nine spectral bands in the visible and infrared wavelengths (410-2250 nm). These measurements can be used to determine aerosol and cloud properties. RSP has a time resolution of 0.8 seconds, a field of view of 14 mrad, and a horizontal resolution of approximately 100 meters at an altitude of 5 km.

The High Spectral Resolution Lidar (HSRL) is an airborne lidar system developed at NASA Langley Research Center (LaRC). It uses the HSRL technique at 532 nm and the standard backscatter technique at 1064 nm to provide profile measurements of aerosol backscatter, extinction, and depolarization. The profiles of aerosol backscatter and depolarization typically have a vertical resolution of 30 m and a horizontal resolution of about 1 km. For the extinction profiles, the vertical resolution is 300 m with a horizontal resolution of approximately 6 km. HSRL is usually flown during investigations to validate observations from the CALIPSO spaceborne lidar.

This description will be added in future versions

The Aerosol Mass Spectrometer (AMS) is an in situ spectrometer developed by Aerodyne Research. It employs quadrupole mass spectrometry to measure aerosol chemical composition and properties. It can detect particles ranging from 40 nm to 1 micron in size and has a time resolution of up to 10 Hz. It can be installed on aircraft, research vessels, mobile laboratories, or other ground-based platforms.

Condensation Particle Counters (CPCs) are in situ sensors that measure aerosol particle concentrations. CPCs determine aerosol levels by condensing fluid onto particles, causing them to grow to sizes detectable by optical scattering. Typically, CPCs can detect particles ranging from 7 nm to 3 μm, measure concentrations up to 100,000 particles per cubic centimeter, and provide readings every second. CPCs are manufactured by TSI Incorporated and can be used on airborne, shipborne, and ground-based platforms.

The Carbon monOxide by Attenuated Laser Transmission (COBALT) is an in situ airborne spectrometer made by Los Gatos Research. It uses off-axis integrated cavity output spectroscopy (OA-ICOS) to measure carbon monoxide in the troposphere and tropopause. COBALT operates at a wavelength of 4.60 μm and has a typical sampling rate of 1 Hz. COBALT delivers measurements with a precision of 0.2 ppbv and does not need regular calibration.

The Particle Soot Absorption Photometer (PSAP) is an in situ airborne photometer manufactured by Radiance Research. It applies Beer's Law to measure the change in light transmission of aerosol particles. These measurements help determine aerosol absorption and extinction. PSAP operates across three wavelengths (467, 530, and 660 nm) and has a 1-second time resolution. It is usually deployed on aircraft, but it can also be used on ships and vehicles.

Generic-Chemistry Related Sensors (Gen-Chemistry) refers to non-specific instruments on a platform used for atmospheric chemistry measurements. These are typically in situ analyzers that measure various chemical compounds such as trace gases, halocarbons, volatile organic compounds, nitrates, aerosols, and other chemical species. Measurements can include mixing ratio, composition, particle size, optical properties, and particle size distribution.

Generic-Atmospheric State (Gen-AtmsState) refers to non-specific instruments on a platform used for measurements of atmospheric state parameters. These are typically in situ sensors that measure temperature, pressure, humidity, and wind speed/direction. Types of atmospheric state instruments include thermometers, hygrometers, barometers, and anemometers.

The Optical Particle Counter is an instrument based on the principle of light scattering from particles. It is a real time instrument that is typically used to measure particles above 0.05 μm in diameter.

The Aethalometer is an in situ aerosol measuring device made by Magee Scientific. It can be used on both airborne and ground-based platforms. It collects aerosols through a filter tape and gauges the attenuation of transmitted light to assess black carbon particle levels. The Aethalometer works across seven optical wavelengths (370, 470, 520, 590, 660, 880, and 950 nm) and delivers data at a rate of 1 Hz. It has a measurement range of 0-500 μg per cubic meter and a resolution of 0.1 μg per cubic meter.

The Cloud Absorption Radiometer (CAR) is an airborne multichannel scanning radiometer developed by the Goddard Space Flight Center (GSFC). CAR provides measurements of scattered radiance and bidirectional surface reflectance across 14 spectral bands in the visible and near-infrared wavelengths (0.34-2.30 µm). It also captures imagery of cloud and surface features on Earth. CAR has a scan rate of 1.67 Hz (100 rpm) and a spatial resolution of 4 meters at nadir, at an altitude of 200 meters above ground.

The Single Particle Soot Photometer (SP2) is an in situ laser-induced photometer developed by Droplet Measurement Technologies. SP2 measures the black carbon (BC) mass in individual aerosol particles, along with their optical and physical properties that contain BC. The device detects aerosol particles with diameters of 200-400 nm and can analyze up to 25,000 particles per second. It operates at a sampling rate of 1 Hz and uses a wavelength of 1.06 μm. It can be used on airborne or ground-based platforms and paired with a Humidified-Dual SP2 (HD-SP2).

Broadband Radiometers (BBR) are modified versions of the Kipp & Zonen CM-22 pyranometers and CG-4 pyrgeometers. They have been adapted for use on airborne platforms through different instrument housing and signal amplification. BBR measures solar irradiance in the 0.2-3.6 μm wavelength range and infrared (IR) irradiance in the 4.5-42 μm range. These measurements can be used to derive net irradiance, radiative forcing, absorption, and albedo. It has a typical sampling rate of 1 Hz and a hemispheric field of view.

The Solar Spectral Flux Radiometer (SSFR) is an airborne radiometer developed by the Ames Atmospheric Radiation Group. It measures solar spectral irradiance in the troposphere. SSFR works within the 300-2150 nm wavelength range and offers a spectral resolution of 8-12 nm. It typically collects data at 1 Hz and has a radiometric accuracy of 3%.

The Aerodynamic Particle Sizer (APS) is an in situ spectrometer manufactured by TSI Instruments. APS measures aerodynamic particles in the 0.5-20 μm size range. It also measures the light-scattering intensity of the particles in the 0.37-20 μm optical size range. APS provides particle size distributions for 52 channels at a typical sampling time of 1 second. It uses a laser diode operating at 655 nm and has a size resolution of 0.02 μm at 1 μm. APS can be deployed on aircraft, ships, or ground-based platforms.

The Condensation Nuclei Counter (CNC) is optical method for counting atmospheric aerosol particles.

The Airborne Tracking Sun Photometer (ATSP) is an airborne device that measures direct solar beam transmission. The ATSP captures solar beam transmission through multiple channels with wavelengths spanning from 354 to 2139 nm. These measurements can be used to determine aerosol optical depth and other aerosol characteristics. Several versions of this instrument exist, including one developed by the NASA Ames Research Center.

The Tandem Differential Mobility Analyzer (TDMA) is an in situ airborne and ground-based analyzer that measures the physical properties of aerosol particles, such as size distribution and concentration. It can measure particles in the size range of 0.013 to 0.75 mm with a size resolution of 0.013 mm at 0.2 mm. The TDMA is often combined with an Aerodynamic Particle Sizer (APS) to enable measurements of particles in the submicron range. A typical measurement sequence of TDMA takes approximately 45 minutes to complete.

Nephelometers are in situ optical sensors that can be airborne or ground-based. They measure the total scattering and backscattering of aerosol particles in the atmosphere. Nephelometers operate at three wavelengths: 450 nm, 550 nm, and 700 nm, with a typical time resolution of 1 Hz.

Spectrometers are instruments used to separate and analyze the spectral components of a substance. They usually measure the electromagnetic radiation that has been reflected, absorbed, or transmitted by the physical sample. Spectrometers can operate across the ultraviolet to infrared spectrum. The most common types include optical, nuclear magnetic resonance, and mass spectrometers. They can be used on aircraft, research vessels, vehicles, and other ground-based platforms.

Thermo Scientific Gas Analyzers are in situ gas analyzers manufactured by ThermoFisher Scientific. They provide precise measurements of various trace gases such as ozone, carbon dioxide, carbon monoxide, and sulfur dioxide. Thermo Scientific Gas Analyzers can be deployed on aircraft, research vessels, and ground-based platforms.

The Airborne Tunable Laser Absorption Spectrometer (ATLAS) is an in situ airborne spectrometer developed by NASA. ATLAS uses second-harmonic absorption spectrometry to measure trace gases in the lower stratosphere, such as nitrous oxide, methane, carbon monoxide, and ozone. The laser inside ATLAS is tuned to the infrared absorption band of the target gas and is frequency modulated at 2 kHz, with second-harmonic detection happening at 4 kHz. ATLAS provides measurements with a time resolution of 1 second and a spatial resolution of about 200 meters when deployed on the ER-2 aircraft.

The Measurements of Atmospheric Carbon Dioxide Over Northwestern North America (MACDON-NA) is an in situ airborne gas analyzer. It is a modified LI-COR model 6252 infrared gas analyzer instrument that measures atmospheric carbon dioxide (CO2). The CO2 measurement is based on the difference in infrared radiation absorption passing through two gas sampling cells. MACDON-NA operates at the 4.26 μm wavelength and a constant pressure of 250 torr. It has a typical response time of 0.1 seconds.

The Particle Into Liquid Sampler (PILS) is an in situ aerosol sampler manufactured by Brechtel Manufacturing Inc. PILS can be used by both ground-based and airborne platforms to gather continuous data on ambient aerosol bulk composition. The particles collected by PILS are mixed with saturated water vapor to form droplets that are analyzed by either an ion chromatograph (IC) or a total organic carbon detector (TOC). PILS can detect aerosol particles ranging from 70 nm to 2.5 μm in size and offers a time resolution of 3 minutes for airborne measurements and 15 minutes for ground-based measurements.

The HR-AMS is an upgraded version of Aerodyne’s AMS instrument. HR-AMS has a high spatial resolution and a time-of-flight measurement technique. HR-AMS is a mass spectrometer that measures aerosols in the troposphere.

The GC-MS instrument is a combination of two instruments: a gas chromatograph and a mass spectrometer. It is used on airborne platforms to study atmospheric chemistry, specifically non-methane halocarbons and volatile organic compounds.

Generic-Chemistry Related Sensors (Gen-Chemistry) refers to non-specific instruments on a platform used for atmospheric chemistry measurements. These are typically in situ analyzers that measure various chemical compounds such as trace gases, halocarbons, volatile organic compounds, nitrates, aerosols, and other chemical species. Measurements can include mixing ratio, composition, particle size, optical properties, and particle size distribution.

Generic-Atmospheric State (Gen-AtmsState) refers to non-specific instruments on a platform used for measurements of atmospheric state parameters. These are typically in situ sensors that measure temperature, pressure, humidity, and wind speed/direction. Types of atmospheric state instruments include thermometers, hygrometers, barometers, and anemometers.

The Proton Transfer Mass Spectrometer (PTR-MS) is an in situ spectrometer used both on aircraft and ground, developed by the University of Innsbruck in Austria. It detects volatile organic compounds (VOCs) without the need for sample preparation at very low concentrations. PTR-MS employs chemical ionization mass spectrometry, enabling quick and highly sensitive VOC detection. It has a signal integration time ranging from 0.5 to 1 second.

The Georgia Institute of Technology Chemical Ionization Mass Spectrometer (GT-CIMS) is an in situ airborne spectrometer. It employs a lower-pressure flow tube reactor to detect reactive nitrogen species such as nitric acid and peroxyacetyl nitrate (PAN) in the lower atmosphere. GT-CIMS typically has a temporal resolution of 1 second and a detection limit of 10 pptv.

This description will be added in a future version.

The Thermal-Dissociation Laser Induced Fluorescence (TD-LIF) is an in situ airborne sensor developed at UC Berkeley. It combines the TD and LIF techniques to measure nitrogen dioxide (NO2), peroxynitrates, nitric acid (HNO3), and other stable organic nitrates in the atmosphere. TD-LIF operates at a wavelength of 585 nm and typically measures at a frequency of 1 Hz.

The Trace Organic Gas Analyzer (TOGA) is an in situ airborne analyzer that measures volatile organic compounds (VOCs) in the atmosphere. It combines fast gas chromatography and mass spectrometry to provide atmospheric mixing ratios of VOCs. It can detect a wide range of VOCs with high precision (<3%) and accuracy (20% or better), with a time resolution of 40 seconds for a 2-minute cycle.

This description will be added in a future version.

LI-COR Gas Analyzer is an in situ gas analyzer manufactured by LI-COR. They can be deployed on aircraft, research vessels, vehicles, balloons, and ground-based platforms. They provide measurements of various trace gases such as carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and water vapor (H2O). Most models use Optical Feedback-Cavity Enhanced Absorption Spectroscopy (OF-CEAS) to collect measurements. LI-COR gas analyzers have a typical measurement rate of 1 Hz and an operating temperature range of -25 to 45 degrees Celsius.

The Scanning Mobility Particle Sizer (SMPS) is an in situ aerosol sensor that can be operated on airborne or ground-based platforms, manufactured by TSI Incorporated. SMPS uses a differential mobility analyzer (DMA) to measure the electrical mobility diameter of aerosol particles, which helps determine the size distribution. It also counts the number of aerosol particles using a condensation particle counter (CPC). It detects particles in the size range of 10-1000 nm and typically takes about 10 seconds to complete each scan.

The Aethalometer is an in situ aerosol measuring device made by Magee Scientific. It can be used on both airborne and ground-based platforms. It collects aerosols through a filter tape and gauges the attenuation of transmitted light to assess black carbon particle levels. The Aethalometer works across seven optical wavelengths (370, 470, 520, 590, 660, 880, and 950 nm) and delivers data at a rate of 1 Hz. It has a measurement range of 0-500 μg per cubic meter and a resolution of 0.1 μg per cubic meter.

The Cloud Aerosol and Precipitation Spectrometer (CAPS) is an in situ airborne spectrometer manufactured by Droplet Measurement Technologies. It combines the Cloud Imaging Probe (CIP), the Cloud and Aerosol Spectrometer (CAS), and the Hotwire Liquid Water Content (LWC) Sensor into a single instrument. CAPS measures the size distribution of aerosol, cloud, and liquid droplets for particles between 50-1600 μm in size, with a time resolution of 1 Hz. It can also capture images of cloud particles and provide measurements of temperature, pressure, and LWC.

The Soluble Acidic Gases and Aerosols (SAGA) is an in-situ airborne sampler owned and operated by the University of New Hampshire. It uses a mist chamber and ion chromatography to collect and analyze specific aerosol species. It can provide samples of nitric acid, chloride, sulfates, nitrates, sodium, potassium, ammonium, and calcium. SAGA has a typical sampling interval of 5 to 15 minutes and a detection limit of 1 to 25 pptv, depending on the sampled species.

A Tunable Diode Laser Absorption Spectrometer (TDLAS) is an in situ optical spectrometer used either on aircraft or on the ground. TDLAS detects the wavelength-dependent absorption of light to measure the concentrations of various trace gases. It can also identify the gas species' temperature, pressure, velocity, and mass flux when applicable. TDLAS typically has a time resolution of 1 second.

The Ultra-High Sensitivity Aerosol Spectrometer (UHSAS) is an in situ spectrometer developed by Droplet Measurement Technologies. It can be used on both airborne and ground-based platforms to measure aerosol size distribution and concentration. UHSAS determines particle size by detecting the peak light signals from aerosol particles illuminated by a 1054 nm laser. It can sample particles in the 60–1000 nm size range and operates at a sampling frequency of 10 Hz.

The Single Particle Soot Photometer (SP2) is an in situ laser-induced photometer developed by Droplet Measurement Technologies. SP2 measures the black carbon (BC) mass in individual aerosol particles, along with their optical and physical properties that contain BC. The device detects aerosol particles with diameters of 200-400 nm and can analyze up to 25,000 particles per second. It operates at a sampling rate of 1 Hz and uses a wavelength of 1.06 μm. It can be used on airborne or ground-based platforms and paired with a Humidified-Dual SP2 (HD-SP2).

The Airborne Tropospheric Hydrogen Oxides Sensor (ATHOS) is an in situ airborne sensor developed by Penn State University. ATHOS uses a laser-induced fluorescence (LIF) technique to measure hydroxide (OH) and hydroperoxyl (HO2) in the atmosphere. ATHOS operates near the 308 nm wavelength, has a pulse repetition frequency of 3 kHz, and has a typical time resolution of 20-30 seconds. It was designed to be installed on NASA’s DC-8 aircraft and can collect measurements of OH and HO2 in clear sky and light cloud conditions.

The Differential Absorption Lidar (DIAL) is an airborne lidar system developed at NASA’s Langley Research Center (LaRC). It uses four lasers to detect lidar backscatter and provide profile measurements of ozone and aerosols in the atmosphere. DIAL operates in the ultraviolet (289-300 nm) for ozone detection and in the visible (572-600 nm) and infrared (1064 nm) for aerosols. It has a horizontal spatial resolution of approximately 15 km and a measurement accuracy of 5 ppbv.

The Whole Air Sampler (WAS) is an airborne in-situ instrument that collects air samples for analyzing trace gases, such as nonmethane hydrocarbons (NMHCs), halocarbons, alkyl nitrates, and various sulfur compounds found in the troposphere. Air samples collected by the WAS are then analyzed using gas chromatography and mass spectrometry to identify the gases present. The WAS collects samples every minute, allowing scientists to get a clear picture of the environment's chemical composition as research aircraft pass through.

The Difference Frequency Generation Absorption Spectrometer (DFGAS) is an in situ airborne spectrometer developed by the National Center for Atmospheric Research (NCAR). It employs difference-frequency generation (DFG) at 3.5 μm by combining two infrared laser sources operating at 1562 and 1083 nm to measure formaldehyde in the atmosphere. DFGAS gathers measurements in 1-second intervals for approximately 60 to 120 seconds, depending on measurement requirements. DFGAS has since been replaced by the Compact Atmospheric Multispecies Spectrometer (CAMS).

The Aerodynamic Particle Sizer (APS) is an in situ spectrometer manufactured by TSI Instruments. APS measures aerodynamic particles in the 0.5-20 μm size range. It also measures the light-scattering intensity of the particles in the 0.37-20 μm optical size range. APS provides particle size distributions for 52 channels at a typical sampling time of 1 second. It uses a laser diode operating at 655 nm and has a size resolution of 0.02 μm at 1 μm. APS can be deployed on aircraft, ships, or ground-based platforms.

The Condensation Nuclei Counter (CNC) is optical method for counting atmospheric aerosol particles.

The Diode Laser Hygrometer (DLH) is an in situ airborne hygrometer developed by NASA’s Langley Research Center (LaRC). It uses tunable diode laser absorption to detect water vapor in the atmosphere. DLH operates in the near-infrared range at about 1.4 μm and has a measurement frequency of 100 Hz. It can deliver precise measurements of water vapor even when flying through clouds.

NOx/NOxy is an in situ chemiluminescence instrument that measures nitrogen oxides and ozone in the atmosphere. It offers a spatial resolution better than 100 meters at typical DC-8 research flight speeds. NOx/NOxy can be used on ground-based, airborne, and shipborne platforms, enabling it to support various atmospheric chemistry and air quality studies.

Nephelometers are in situ optical sensors that can be airborne or ground-based. They measure the total scattering and backscattering of aerosol particles in the atmosphere. Nephelometers operate at three wavelengths: 450 nm, 550 nm, and 700 nm, with a typical time resolution of 1 Hz.

Spectrometers are instruments used to separate and analyze the spectral components of a substance. They usually measure the electromagnetic radiation that has been reflected, absorbed, or transmitted by the physical sample. Spectrometers can operate across the ultraviolet to infrared spectrum. The most common types include optical, nuclear magnetic resonance, and mass spectrometers. They can be used on aircraft, research vessels, vehicles, and other ground-based platforms.

The Charged-couple device (CCD) Actinic Flux Spectroradiometer (CAFS) is an in situ airborne spectroradiometer developed by the Atmospheric Radiation Investigations and Measurements (ARIM) laboratory at NCAR. CAFS measures spectrally resolved ultraviolet and visible actinic flux between 280-650 nm. These measurements can be used to derive the photolysis frequencies for several chemical compounds such as ozone, nitrogen dioxide, formaldehyde, and nitrate. CAFS has a temporal resolution of 1 Hz and a wavelength resolution of about 1.8 nm at 297 nm.

The CalTech Chemical Ionization Mass Spectrometer (CIT-CIMS) is an in situ airborne single-mass spectrometer. CIT-CIMS uses CF3O-ion chemistry and compact time-of-flight and triple quadrupole spectrometers to measure specific atmospheric trace gases such as nitric acid, hydrogen peroxide, and sulfur dioxide. It was designed with rapid scan capabilities, enabling it to operate at a high temporal resolution (10 Hz) and detect a wide range of masses. CIT-CIMS is typically used for airborne observations but can also be employed for ground-based measurements.

The Langley Aerosol Research Group Experiment (LARGE) is an in situ airborne instrument suite that measures aerosol and cloud microphysical and optical properties, such as size distribution, number concentration, and scattering and absorption coefficients. LARGE includes several instruments, such as the Ultra-High Sensitivity Aerosol Spectrometer (UHSAS), Particle-Into-Liquid Sampler (PILS), Particle Soot Absorption Photometer (PSAP), Cloud and Aerosol Spectrometer (CAS), Cloud Imaging Probe (CIP), and additional cloud and aerosol sensors. The LARGE instruments operate over the 450-700 nm wavelength range, detect particles ranging from 0.003 to 20 μm, and measure at a frequency of 1 Hz. It is primarily used for airborne measurements but can also be deployed on ground-based platforms like vehicles.

Ozonesondes are in situ balloon-borne instruments used to measure ozone concentration profiles. An ozonesonde consists of an electrochemical ozone sensor connected with a meteorological radiosonde to collect ozone, temperature, pressure, and humidity measurements as it ascends through the atmosphere. It provides ozone profile measurements at a resolution of 100 to 150 m. Ozonesondes have a typical measurement rate of 0.1 Hz and can collect profiles up to around 35 km.

The Multi-Axis Differential Optical Absorption Spectrometer (MAX-DOAS) is a ground-based passive spectrometer. It measures the scattered solar light at different elevations to determine trace gases in the troposphere. MAX-DOAS is designed to have low residual error in the ultraviolet and visible spectrums, allowing detection in both pristine and polluted environments. Typical MAX-DOAS instruments operate in the 300-700 nm spectral range with a spectral resolution of 0.4-1.5 nm depending on the target species.

The UAF Cloud Polarization Lidar (CPL) is a ground-based lidar located at the Arctic Facility for Atmospheric Remote Sensing (AFARS) at the University of Alaska Fairbanks (UAF). It measures lidar backscatter and depolarization ratio using a ruby laser transmitter at 0.694 μm. UAF CPL has a range resolution of 7.5 m and a time resolution of 10 seconds. It provides lidar depolarization ratio measurements with an accuracy of 0.02.

The Measurements of Atmospheric Carbon Dioxide Over Northwestern North America (MACDON-NA) is an in situ airborne gas analyzer. It is a modified LI-COR model 6252 infrared gas analyzer instrument that measures atmospheric carbon dioxide (CO2). The CO2 measurement is based on the difference in infrared radiation absorption passing through two gas sampling cells. MACDON-NA operates at the 4.26 μm wavelength and a constant pressure of 250 torr. It has a typical response time of 0.1 seconds.

The Scanning Spectral Polarimeter (SSP) is an airborne polarimeter developed by Colorado State University. It uses a rotating optical bandpass filter to measure spectral radiance and fluxes across the 400 to 4000 nm wavelength range. These measurements help to determine cloud optical and microphysical properties. SSP has an accuracy of about 3% and a field of view of 20 mrad.

The Particle Into Liquid Sampler (PILS) is an in situ aerosol sampler manufactured by Brechtel Manufacturing Inc. PILS can be used by both ground-based and airborne platforms to gather continuous data on ambient aerosol bulk composition. The particles collected by PILS are mixed with saturated water vapor to form droplets that are analyzed by either an ion chromatograph (IC) or a total organic carbon detector (TOC). PILS can detect aerosol particles ranging from 70 nm to 2.5 μm in size and offers a time resolution of 3 minutes for airborne measurements and 15 minutes for ground-based measurements.

The HR-AMS is an upgraded version of Aerodyne’s AMS instrument. HR-AMS has a high spatial resolution and a time-of-flight measurement technique. HR-AMS is a mass spectrometer that measures aerosols in the troposphere.

The GC-MS instrument is a combination of two instruments: a gas chromatograph and a mass spectrometer. It is used on airborne platforms to study atmospheric chemistry, specifically non-methane halocarbons and volatile organic compounds.

Generic-Chemistry Related Sensors (Gen-Chemistry) refers to non-specific instruments on a platform used for atmospheric chemistry measurements. These are typically in situ analyzers that measure various chemical compounds such as trace gases, halocarbons, volatile organic compounds, nitrates, aerosols, and other chemical species. Measurements can include mixing ratio, composition, particle size, optical properties, and particle size distribution.

Generic-Atmospheric State (Gen-AtmsState) refers to non-specific instruments on a platform used for measurements of atmospheric state parameters. These are typically in situ sensors that measure temperature, pressure, humidity, and wind speed/direction. Types of atmospheric state instruments include thermometers, hygrometers, barometers, and anemometers.

The Proton Transfer Mass Spectrometer (PTR-MS) is an in situ spectrometer used both on aircraft and ground, developed by the University of Innsbruck in Austria. It detects volatile organic compounds (VOCs) without the need for sample preparation at very low concentrations. PTR-MS employs chemical ionization mass spectrometry, enabling quick and highly sensitive VOC detection. It has a signal integration time ranging from 0.5 to 1 second.

The Georgia Institute of Technology Chemical Ionization Mass Spectrometer (GT-CIMS) is an in situ airborne spectrometer. It employs a lower-pressure flow tube reactor to detect reactive nitrogen species such as nitric acid and peroxyacetyl nitrate (PAN) in the lower atmosphere. GT-CIMS typically has a temporal resolution of 1 second and a detection limit of 10 pptv.

This description will be added in a future version.

The Thermal-Dissociation Laser Induced Fluorescence (TD-LIF) is an in situ airborne sensor developed at UC Berkeley. It combines the TD and LIF techniques to measure nitrogen dioxide (NO2), peroxynitrates, nitric acid (HNO3), and other stable organic nitrates in the atmosphere. TD-LIF operates at a wavelength of 585 nm and typically measures at a frequency of 1 Hz.

The Trace Organic Gas Analyzer (TOGA) is an in situ airborne analyzer that measures volatile organic compounds (VOCs) in the atmosphere. It combines fast gas chromatography and mass spectrometry to provide atmospheric mixing ratios of VOCs. It can detect a wide range of VOCs with high precision (<3%) and accuracy (20% or better), with a time resolution of 40 seconds for a 2-minute cycle.

This description will be added in a future version.

LI-COR Gas Analyzer is an in situ gas analyzer manufactured by LI-COR. They can be deployed on aircraft, research vessels, vehicles, balloons, and ground-based platforms. They provide measurements of various trace gases such as carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and water vapor (H2O). Most models use Optical Feedback-Cavity Enhanced Absorption Spectroscopy (OF-CEAS) to collect measurements. LI-COR gas analyzers have a typical measurement rate of 1 Hz and an operating temperature range of -25 to 45 degrees Celsius.

The Scanning Mobility Particle Sizer (SMPS) is an in situ aerosol sensor that can be operated on airborne or ground-based platforms, manufactured by TSI Incorporated. SMPS uses a differential mobility analyzer (DMA) to measure the electrical mobility diameter of aerosol particles, which helps determine the size distribution. It also counts the number of aerosol particles using a condensation particle counter (CPC). It detects particles in the size range of 10-1000 nm and typically takes about 10 seconds to complete each scan.

The Aethalometer is an in situ aerosol measuring device made by Magee Scientific. It can be used on both airborne and ground-based platforms. It collects aerosols through a filter tape and gauges the attenuation of transmitted light to assess black carbon particle levels. The Aethalometer works across seven optical wavelengths (370, 470, 520, 590, 660, 880, and 950 nm) and delivers data at a rate of 1 Hz. It has a measurement range of 0-500 μg per cubic meter and a resolution of 0.1 μg per cubic meter.

The Cloud Aerosol and Precipitation Spectrometer (CAPS) is an in situ airborne spectrometer manufactured by Droplet Measurement Technologies. It combines the Cloud Imaging Probe (CIP), the Cloud and Aerosol Spectrometer (CAS), and the Hotwire Liquid Water Content (LWC) Sensor into a single instrument. CAPS measures the size distribution of aerosol, cloud, and liquid droplets for particles between 50-1600 μm in size, with a time resolution of 1 Hz. It can also capture images of cloud particles and provide measurements of temperature, pressure, and LWC.

The Soluble Acidic Gases and Aerosols (SAGA) is an in-situ airborne sampler owned and operated by the University of New Hampshire. It uses a mist chamber and ion chromatography to collect and analyze specific aerosol species. It can provide samples of nitric acid, chloride, sulfates, nitrates, sodium, potassium, ammonium, and calcium. SAGA has a typical sampling interval of 5 to 15 minutes and a detection limit of 1 to 25 pptv, depending on the sampled species.

A Tunable Diode Laser Absorption Spectrometer (TDLAS) is an in situ optical spectrometer used either on aircraft or on the ground. TDLAS detects the wavelength-dependent absorption of light to measure the concentrations of various trace gases. It can also identify the gas species' temperature, pressure, velocity, and mass flux when applicable. TDLAS typically has a time resolution of 1 second.

The Ultra-High Sensitivity Aerosol Spectrometer (UHSAS) is an in situ spectrometer developed by Droplet Measurement Technologies. It can be used on both airborne and ground-based platforms to measure aerosol size distribution and concentration. UHSAS determines particle size by detecting the peak light signals from aerosol particles illuminated by a 1054 nm laser. It can sample particles in the 60–1000 nm size range and operates at a sampling frequency of 10 Hz.

The Airborne Tropospheric Hydrogen Oxides Sensor (ATHOS) is an in situ airborne sensor developed by Penn State University. ATHOS uses a laser-induced fluorescence (LIF) technique to measure hydroxide (OH) and hydroperoxyl (HO2) in the atmosphere. ATHOS operates near the 308 nm wavelength, has a pulse repetition frequency of 3 kHz, and has a typical time resolution of 20-30 seconds. It was designed to be installed on NASA’s DC-8 aircraft and can collect measurements of OH and HO2 in clear sky and light cloud conditions.

The Differential Absorption Lidar (DIAL) is an airborne lidar system developed at NASA’s Langley Research Center (LaRC). It uses four lasers to detect lidar backscatter and provide profile measurements of ozone and aerosols in the atmosphere. DIAL operates in the ultraviolet (289-300 nm) for ozone detection and in the visible (572-600 nm) and infrared (1064 nm) for aerosols. It has a horizontal spatial resolution of approximately 15 km and a measurement accuracy of 5 ppbv.

The Whole Air Sampler (WAS) is an airborne in-situ instrument that collects air samples for analyzing trace gases, such as nonmethane hydrocarbons (NMHCs), halocarbons, alkyl nitrates, and various sulfur compounds found in the troposphere. Air samples collected by the WAS are then analyzed using gas chromatography and mass spectrometry to identify the gases present. The WAS collects samples every minute, allowing scientists to get a clear picture of the environment's chemical composition as research aircraft pass through.

The Difference Frequency Generation Absorption Spectrometer (DFGAS) is an in situ airborne spectrometer developed by the National Center for Atmospheric Research (NCAR). It employs difference-frequency generation (DFG) at 3.5 μm by combining two infrared laser sources operating at 1562 and 1083 nm to measure formaldehyde in the atmosphere. DFGAS gathers measurements in 1-second intervals for approximately 60 to 120 seconds, depending on measurement requirements. DFGAS has since been replaced by the Compact Atmospheric Multispecies Spectrometer (CAMS).

The Aerodynamic Particle Sizer (APS) is an in situ spectrometer manufactured by TSI Instruments. APS measures aerodynamic particles in the 0.5-20 μm size range. It also measures the light-scattering intensity of the particles in the 0.37-20 μm optical size range. APS provides particle size distributions for 52 channels at a typical sampling time of 1 second. It uses a laser diode operating at 655 nm and has a size resolution of 0.02 μm at 1 μm. APS can be deployed on aircraft, ships, or ground-based platforms.

The Condensation Nuclei Counter (CNC) is optical method for counting atmospheric aerosol particles.

The Diode Laser Hygrometer (DLH) is an in situ airborne hygrometer developed by NASA’s Langley Research Center (LaRC). It uses tunable diode laser absorption to detect water vapor in the atmosphere. DLH operates in the near-infrared range at about 1.4 μm and has a measurement frequency of 100 Hz. It can deliver precise measurements of water vapor even when flying through clouds.

NOx/NOxy is an in situ chemiluminescence instrument that measures nitrogen oxides and ozone in the atmosphere. It offers a spatial resolution better than 100 meters at typical DC-8 research flight speeds. NOx/NOxy can be used on ground-based, airborne, and shipborne platforms, enabling it to support various atmospheric chemistry and air quality studies.

Nephelometers are in situ optical sensors that can be airborne or ground-based. They measure the total scattering and backscattering of aerosol particles in the atmosphere. Nephelometers operate at three wavelengths: 450 nm, 550 nm, and 700 nm, with a typical time resolution of 1 Hz.

Spectrometers are instruments used to separate and analyze the spectral components of a substance. They usually measure the electromagnetic radiation that has been reflected, absorbed, or transmitted by the physical sample. Spectrometers can operate across the ultraviolet to infrared spectrum. The most common types include optical, nuclear magnetic resonance, and mass spectrometers. They can be used on aircraft, research vessels, vehicles, and other ground-based platforms.

The Charged-couple device (CCD) Actinic Flux Spectroradiometer (CAFS) is an in situ airborne spectroradiometer developed by the Atmospheric Radiation Investigations and Measurements (ARIM) laboratory at NCAR. CAFS measures spectrally resolved ultraviolet and visible actinic flux between 280-650 nm. These measurements can be used to derive the photolysis frequencies for several chemical compounds such as ozone, nitrogen dioxide, formaldehyde, and nitrate. CAFS has a temporal resolution of 1 Hz and a wavelength resolution of about 1.8 nm at 297 nm.

The CalTech Chemical Ionization Mass Spectrometer (CIT-CIMS) is an in situ airborne single-mass spectrometer. CIT-CIMS uses CF3O-ion chemistry and compact time-of-flight and triple quadrupole spectrometers to measure specific atmospheric trace gases such as nitric acid, hydrogen peroxide, and sulfur dioxide. It was designed with rapid scan capabilities, enabling it to operate at a high temporal resolution (10 Hz) and detect a wide range of masses. CIT-CIMS is typically used for airborne observations but can also be employed for ground-based measurements.

The Differential Absorption Carbon monOxide Measurements (DACOM) is an airborne in situ spectrometer system. It uses the differential absorption technique and an infrared tunable diode laser (TDL) to collect measurements of nitrous oxide (N2O), carbon dioxide (CO2), carbon monoxide (CO), and methane (CH4) in the atmosphere. DACOM operates across the 4.7, 4.5, and 3.3 μm wavelengths to access the absorption lines for CO, N2O, and CH4. It has a measurement frequency of 5 Hz and a precision of about 1 ppbv.

The Langley Aerosol Research Group Experiment (LARGE) is an in situ airborne instrument suite that measures aerosol and cloud microphysical and optical properties, such as size distribution, number concentration, and scattering and absorption coefficients. LARGE includes several instruments, such as the Ultra-High Sensitivity Aerosol Spectrometer (UHSAS), Particle-Into-Liquid Sampler (PILS), Particle Soot Absorption Photometer (PSAP), Cloud and Aerosol Spectrometer (CAS), Cloud Imaging Probe (CIP), and additional cloud and aerosol sensors. The LARGE instruments operate over the 450-700 nm wavelength range, detect particles ranging from 0.003 to 20 μm, and measure at a frequency of 1 Hz. It is primarily used for airborne measurements but can also be deployed on ground-based platforms like vehicles.

The Measurements of Atmospheric Carbon Dioxide Over Northwestern North America (MACDON-NA) is an in situ airborne gas analyzer. It is a modified LI-COR model 6252 infrared gas analyzer instrument that measures atmospheric carbon dioxide (CO2). The CO2 measurement is based on the difference in infrared radiation absorption passing through two gas sampling cells. MACDON-NA operates at the 4.26 μm wavelength and a constant pressure of 250 torr. It has a typical response time of 0.1 seconds.

The Particle Into Liquid Sampler (PILS) is an in situ aerosol sampler manufactured by Brechtel Manufacturing Inc. PILS can be used by both ground-based and airborne platforms to gather continuous data on ambient aerosol bulk composition. The particles collected by PILS are mixed with saturated water vapor to form droplets that are analyzed by either an ion chromatograph (IC) or a total organic carbon detector (TOC). PILS can detect aerosol particles ranging from 70 nm to 2.5 μm in size and offers a time resolution of 3 minutes for airborne measurements and 15 minutes for ground-based measurements.

The HR-AMS is an upgraded version of Aerodyne’s AMS instrument. HR-AMS has a high spatial resolution and a time-of-flight measurement technique. HR-AMS is a mass spectrometer that measures aerosols in the troposphere.

The GC-MS instrument is a combination of two instruments: a gas chromatograph and a mass spectrometer. It is used on airborne platforms to study atmospheric chemistry, specifically non-methane halocarbons and volatile organic compounds.

Generic-Chemistry Related Sensors (Gen-Chemistry) refers to non-specific instruments on a platform used for atmospheric chemistry measurements. These are typically in situ analyzers that measure various chemical compounds such as trace gases, halocarbons, volatile organic compounds, nitrates, aerosols, and other chemical species. Measurements can include mixing ratio, composition, particle size, optical properties, and particle size distribution.

Generic-Atmospheric State (Gen-AtmsState) refers to non-specific instruments on a platform used for measurements of atmospheric state parameters. These are typically in situ sensors that measure temperature, pressure, humidity, and wind speed/direction. Types of atmospheric state instruments include thermometers, hygrometers, barometers, and anemometers.

The Proton Transfer Mass Spectrometer (PTR-MS) is an in situ spectrometer used both on aircraft and ground, developed by the University of Innsbruck in Austria. It detects volatile organic compounds (VOCs) without the need for sample preparation at very low concentrations. PTR-MS employs chemical ionization mass spectrometry, enabling quick and highly sensitive VOC detection. It has a signal integration time ranging from 0.5 to 1 second.

The Georgia Institute of Technology Chemical Ionization Mass Spectrometer (GT-CIMS) is an in situ airborne spectrometer. It employs a lower-pressure flow tube reactor to detect reactive nitrogen species such as nitric acid and peroxyacetyl nitrate (PAN) in the lower atmosphere. GT-CIMS typically has a temporal resolution of 1 second and a detection limit of 10 pptv.

This description will be added in a future version.

The Thermal-Dissociation Laser Induced Fluorescence (TD-LIF) is an in situ airborne sensor developed at UC Berkeley. It combines the TD and LIF techniques to measure nitrogen dioxide (NO2), peroxynitrates, nitric acid (HNO3), and other stable organic nitrates in the atmosphere. TD-LIF operates at a wavelength of 585 nm and typically measures at a frequency of 1 Hz.

The Trace Organic Gas Analyzer (TOGA) is an in situ airborne analyzer that measures volatile organic compounds (VOCs) in the atmosphere. It combines fast gas chromatography and mass spectrometry to provide atmospheric mixing ratios of VOCs. It can detect a wide range of VOCs with high precision (<3%) and accuracy (20% or better), with a time resolution of 40 seconds for a 2-minute cycle.

This description will be added in a future version.

LI-COR Gas Analyzer is an in situ gas analyzer manufactured by LI-COR. They can be deployed on aircraft, research vessels, vehicles, balloons, and ground-based platforms. They provide measurements of various trace gases such as carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and water vapor (H2O). Most models use Optical Feedback-Cavity Enhanced Absorption Spectroscopy (OF-CEAS) to collect measurements. LI-COR gas analyzers have a typical measurement rate of 1 Hz and an operating temperature range of -25 to 45 degrees Celsius.

The Scanning Mobility Particle Sizer (SMPS) is an in situ aerosol sensor that can be operated on airborne or ground-based platforms, manufactured by TSI Incorporated. SMPS uses a differential mobility analyzer (DMA) to measure the electrical mobility diameter of aerosol particles, which helps determine the size distribution. It also counts the number of aerosol particles using a condensation particle counter (CPC). It detects particles in the size range of 10-1000 nm and typically takes about 10 seconds to complete each scan.

The Aethalometer is an in situ aerosol measuring device made by Magee Scientific. It can be used on both airborne and ground-based platforms. It collects aerosols through a filter tape and gauges the attenuation of transmitted light to assess black carbon particle levels. The Aethalometer works across seven optical wavelengths (370, 470, 520, 590, 660, 880, and 950 nm) and delivers data at a rate of 1 Hz. It has a measurement range of 0-500 μg per cubic meter and a resolution of 0.1 μg per cubic meter.

The Cloud Aerosol and Precipitation Spectrometer (CAPS) is an in situ airborne spectrometer manufactured by Droplet Measurement Technologies. It combines the Cloud Imaging Probe (CIP), the Cloud and Aerosol Spectrometer (CAS), and the Hotwire Liquid Water Content (LWC) Sensor into a single instrument. CAPS measures the size distribution of aerosol, cloud, and liquid droplets for particles between 50-1600 μm in size, with a time resolution of 1 Hz. It can also capture images of cloud particles and provide measurements of temperature, pressure, and LWC.

The Soluble Acidic Gases and Aerosols (SAGA) is an in-situ airborne sampler owned and operated by the University of New Hampshire. It uses a mist chamber and ion chromatography to collect and analyze specific aerosol species. It can provide samples of nitric acid, chloride, sulfates, nitrates, sodium, potassium, ammonium, and calcium. SAGA has a typical sampling interval of 5 to 15 minutes and a detection limit of 1 to 25 pptv, depending on the sampled species.

A Tunable Diode Laser Absorption Spectrometer (TDLAS) is an in situ optical spectrometer used either on aircraft or on the ground. TDLAS detects the wavelength-dependent absorption of light to measure the concentrations of various trace gases. It can also identify the gas species' temperature, pressure, velocity, and mass flux when applicable. TDLAS typically has a time resolution of 1 second.

The Ultra-High Sensitivity Aerosol Spectrometer (UHSAS) is an in situ spectrometer developed by Droplet Measurement Technologies. It can be used on both airborne and ground-based platforms to measure aerosol size distribution and concentration. UHSAS determines particle size by detecting the peak light signals from aerosol particles illuminated by a 1054 nm laser. It can sample particles in the 60–1000 nm size range and operates at a sampling frequency of 10 Hz.

The Single Particle Soot Photometer (SP2) is an in situ laser-induced photometer developed by Droplet Measurement Technologies. SP2 measures the black carbon (BC) mass in individual aerosol particles, along with their optical and physical properties that contain BC. The device detects aerosol particles with diameters of 200-400 nm and can analyze up to 25,000 particles per second. It operates at a sampling rate of 1 Hz and uses a wavelength of 1.06 μm. It can be used on airborne or ground-based platforms and paired with a Humidified-Dual SP2 (HD-SP2).

The Airborne Tropospheric Hydrogen Oxides Sensor (ATHOS) is an in situ airborne sensor developed by Penn State University. ATHOS uses a laser-induced fluorescence (LIF) technique to measure hydroxide (OH) and hydroperoxyl (HO2) in the atmosphere. ATHOS operates near the 308 nm wavelength, has a pulse repetition frequency of 3 kHz, and has a typical time resolution of 20-30 seconds. It was designed to be installed on NASA’s DC-8 aircraft and can collect measurements of OH and HO2 in clear sky and light cloud conditions.

The Differential Absorption Lidar (DIAL) is an airborne lidar system developed at NASA’s Langley Research Center (LaRC). It uses four lasers to detect lidar backscatter and provide profile measurements of ozone and aerosols in the atmosphere. DIAL operates in the ultraviolet (289-300 nm) for ozone detection and in the visible (572-600 nm) and infrared (1064 nm) for aerosols. It has a horizontal spatial resolution of approximately 15 km and a measurement accuracy of 5 ppbv.

The Whole Air Sampler (WAS) is an airborne in-situ instrument that collects air samples for analyzing trace gases, such as nonmethane hydrocarbons (NMHCs), halocarbons, alkyl nitrates, and various sulfur compounds found in the troposphere. Air samples collected by the WAS are then analyzed using gas chromatography and mass spectrometry to identify the gases present. The WAS collects samples every minute, allowing scientists to get a clear picture of the environment's chemical composition as research aircraft pass through.

The Difference Frequency Generation Absorption Spectrometer (DFGAS) is an in situ airborne spectrometer developed by the National Center for Atmospheric Research (NCAR). It employs difference-frequency generation (DFG) at 3.5 μm by combining two infrared laser sources operating at 1562 and 1083 nm to measure formaldehyde in the atmosphere. DFGAS gathers measurements in 1-second intervals for approximately 60 to 120 seconds, depending on measurement requirements. DFGAS has since been replaced by the Compact Atmospheric Multispecies Spectrometer (CAMS).

The Aerodynamic Particle Sizer (APS) is an in situ spectrometer manufactured by TSI Instruments. APS measures aerodynamic particles in the 0.5-20 μm size range. It also measures the light-scattering intensity of the particles in the 0.37-20 μm optical size range. APS provides particle size distributions for 52 channels at a typical sampling time of 1 second. It uses a laser diode operating at 655 nm and has a size resolution of 0.02 μm at 1 μm. APS can be deployed on aircraft, ships, or ground-based platforms.

The Condensation Nuclei Counter (CNC) is optical method for counting atmospheric aerosol particles.

The Diode Laser Hygrometer (DLH) is an in situ airborne hygrometer developed by NASA’s Langley Research Center (LaRC). It uses tunable diode laser absorption to detect water vapor in the atmosphere. DLH operates in the near-infrared range at about 1.4 μm and has a measurement frequency of 100 Hz. It can deliver precise measurements of water vapor even when flying through clouds.

NOx/NOxy is an in situ chemiluminescence instrument that measures nitrogen oxides and ozone in the atmosphere. It offers a spatial resolution better than 100 meters at typical DC-8 research flight speeds. NOx/NOxy can be used on ground-based, airborne, and shipborne platforms, enabling it to support various atmospheric chemistry and air quality studies.

Nephelometers are in situ optical sensors that can be airborne or ground-based. They measure the total scattering and backscattering of aerosol particles in the atmosphere. Nephelometers operate at three wavelengths: 450 nm, 550 nm, and 700 nm, with a typical time resolution of 1 Hz.

Spectrometers are instruments used to separate and analyze the spectral components of a substance. They usually measure the electromagnetic radiation that has been reflected, absorbed, or transmitted by the physical sample. Spectrometers can operate across the ultraviolet to infrared spectrum. The most common types include optical, nuclear magnetic resonance, and mass spectrometers. They can be used on aircraft, research vessels, vehicles, and other ground-based platforms.

The Charged-couple device (CCD) Actinic Flux Spectroradiometer (CAFS) is an in situ airborne spectroradiometer developed by the Atmospheric Radiation Investigations and Measurements (ARIM) laboratory at NCAR. CAFS measures spectrally resolved ultraviolet and visible actinic flux between 280-650 nm. These measurements can be used to derive the photolysis frequencies for several chemical compounds such as ozone, nitrogen dioxide, formaldehyde, and nitrate. CAFS has a temporal resolution of 1 Hz and a wavelength resolution of about 1.8 nm at 297 nm.

The CalTech Chemical Ionization Mass Spectrometer (CIT-CIMS) is an in situ airborne single-mass spectrometer. CIT-CIMS uses CF3O-ion chemistry and compact time-of-flight and triple quadrupole spectrometers to measure specific atmospheric trace gases such as nitric acid, hydrogen peroxide, and sulfur dioxide. It was designed with rapid scan capabilities, enabling it to operate at a high temporal resolution (10 Hz) and detect a wide range of masses. CIT-CIMS is typically used for airborne observations but can also be employed for ground-based measurements.

The Differential Absorption Carbon monOxide Measurements (DACOM) is an airborne in situ spectrometer system. It uses the differential absorption technique and an infrared tunable diode laser (TDL) to collect measurements of nitrous oxide (N2O), carbon dioxide (CO2), carbon monoxide (CO), and methane (CH4) in the atmosphere. DACOM operates across the 4.7, 4.5, and 3.3 μm wavelengths to access the absorption lines for CO, N2O, and CH4. It has a measurement frequency of 5 Hz and a precision of about 1 ppbv.

The Langley Aerosol Research Group Experiment (LARGE) is an in situ airborne instrument suite that measures aerosol and cloud microphysical and optical properties, such as size distribution, number concentration, and scattering and absorption coefficients. LARGE includes several instruments, such as the Ultra-High Sensitivity Aerosol Spectrometer (UHSAS), Particle-Into-Liquid Sampler (PILS), Particle Soot Absorption Photometer (PSAP), Cloud and Aerosol Spectrometer (CAS), Cloud Imaging Probe (CIP), and additional cloud and aerosol sensors. The LARGE instruments operate over the 450-700 nm wavelength range, detect particles ranging from 0.003 to 20 μm, and measure at a frequency of 1 Hz. It is primarily used for airborne measurements but can also be deployed on ground-based platforms like vehicles.