CalWater was a multi-year campaign during the boreal winter over the Sierra Nevada mountain range from 2009 to 2015. NASA was a significant participant only for the 2015 deployment (CalWater 2015) by providing the NASA ER-2 and multiple instruments. The main objectives of CalWater were to study atmospheric rivers' impact on hydrometeorology and aerosols' effects on clouds and precipitation processes. Measurements of aerosols and cloud properties, precipitation, and water vapor were taken by utilizing airborne, ship-borne, and ground-based sensors. CalWater was a collaborative effort between NOAA, the Department of Energy (DoE), the National Science Foundation (NSF), and NASA.
This campaign had multiple deployments from 2009-2015, but only the 2015 deployment is included in this inventory as NASA did not participate in earlier deployments.
The Tail Doppler Radar (TDR) is an airborne vertically scanning, pulse Dopper X-band radar operated by NOAA. It is installed on the tail of the research aircraft and is typically equipped on NOAA’s P-3 aircraft for hurricane and precipitation research missions. TDR measures radar reflectivity and Doppler wind velocities at the 9315 MHz frequency band. It has a horizontal beam width of 1.35 degrees and a range gate spacing of 150 or 300 meters.
A dropsondes or dropwindsondes are in situ instruments designed to be released from aircraft. They are equipped with Global Positioning System (GPS) receivers and sensors to collect profile measurements of pressure, temperature, humidity, wind speed, and direction. Dropsondes are important during field investigations because they allow researchers to collect vertical profiles in remote locations and during severe weather events. Dropsondes typically have a vertical resolution of 5 m and provide measurements of wind speed/direction every 0.25 seconds and temperature, pressure, and humidity every 0.5 seconds.
The Cloud Physics Lidar (CPL) is an airborne lidar system designed specifically to provide multi-wavelength measurements of cirrus clouds, sub-visual cirrus clouds, and aerosols. It measures lidar backscatter across three wavelengths: 355 nm, 532 nm, and 1064 nm. These measurements can be used to derive cloud optical depth, particle size distribution, extinction profiles, aerosol layers, and other properties. CPL has a vertical resolution of 30 m and a typical horizontal resolution of 200 m.
The Airborne Multiangle SpectroPolarimetric Imager (AirMSPI) is a passive remote, airborne pushbroom camera developed by the Jet Propulsion Laboratory (JPL) and engineers from the University of Arizona and the University of Texas. AirMSPI operates across 8 spectral bands (355, 380, 445, 470, 555, 660, 865, 935 nm) to provide multiangle radiance and linear polarization imagery which can be used to retrieve aerosol and cloud microphysical properties. AirMSPI has a spatial resolution of 10-25 m depending on the scan mode and typically provides image frames at a rate of 23 Hz. AirMSPI was designed to fly on the nose of NASA’s ER-2 aircraft and has been utilized in several aerosol and cloud investigations.
The Airborne Visible/Infrared Imaging Spectrometer - Classic (AVIRIS-C) is a passive imaging spectrometer developed at the Jet Propulsion Laboratory (JPL) for Earth remote sensing. AVIRIC-C was designed to operate aboard NASA’s Earth Resources 2 (ER-2) aircraft. It has a spatial resolution of 20 meters and takes 12 scans per second. AVIRIS-C operated in the spectral region of 0.41 µm to 2.45 µm, making it particularly useful for a wide variety of Earth Science applications. It has been replaced by the Next Generation Airborne Visible/Infrared Imaging Spectrometer (AVIRIS-NG), though AVIRIS-C remains in operation.
The High Altitude Monolithic Microwave integrated Circuit (MMIC) Sounding Radiometer (HAMSR) is an airborne microwave sounder developed by the Jet Propulsion Laboratory under the NASA Instrument Incubator Program. HAMSR measures brightness temperature which can be used to derive three-dimensional profiles of temperature, water vapor, and cloud liquid water in the atmosphere. It operates across 25 spectral channels in 3 microwave bands (50-60 GHz, 118 GHz, 183 GHz) and has a sampling frequency of 5 seconds. HAMSR has a horizontal spatial resolution of 2 km at nadir and a field of view of about 40 km at an altitude of 20 km.
Earth Science > Atmosphere > Atmospheric Temperature
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.
Earth Science > Atmosphere > Atmospheric Water Vapor
Earth Science > Atmosphere > Atmospheric Pressure
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Humidity
Earth Science > Atmosphere > Atmospheric Temperature > Surface Temperature > Air Temperature
The Ultra-High Frequency (UHF) Wind Profiler is a ground-based Doppler radar. It measures electromagnetic signals to detect wind speed and direction. UHF Wind Profilers operate at the 300-1000 MHz frequency range. Due to operating at a high frequency, they allow for high-resolution wind measurements within the boundary layer.
Soil moisture probes are in situ ground-based sensors used to measure soil water content. The most common type of soil moisture probes used for scientific research use dielectric permittivity techniques such as capacitance sensors or time-domain reflectometry sensors. These types of probes measure the charge-storage capacity of the soil to determine the soil moisture content. They typically operate at frequencies around 50 MHz and above to reduce sensitivity to salinity. Soil moisture probes provide continuous measurements and are relatively easy to deploy.
The Condensation Nuclei Counter (CNC) is optical method for
counting atmospheric aerosol particles.
Earth Science > >
Rain gauges are ground-based instruments that provide in situ measurements of liquid precipitation amounts over a set time. There are multiple types of rain gauges that each collect and record data differently such as the tipping bucket rain gauge and weighing precipitation gauge. Rain gauges can be deployed in various locations due to their relatively small size and easy set-up and are typically colocated with other precipitation instruments such as disdrometers to provide more details about precipitation being collected such as precipitation rate and size distribution.
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.
S-band radars are ground-based or shipborne radars that operate at the frequency range of 2-4 GHz. They provide measurements of radar reflectivity, Doppler velocity, and other radar parameters to characterize precipitation and clouds. They are not easily attenuated making them useful for near and far-range weather observations.
Aethalometer is an in situ aerosol instrument manufactured by Magee Scientific that can be deployed on either airborne or ground-based platforms. It samples aerosols through a filter tape and measures the attenuation of transmitted light to determine the concentration of black carbon particles. The Aethalometer operates across seven optical wavelengths (370, 470, 520, 590, 660, 880, and 950 nm) and can provide 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 Condensation Nuclei Counter (CNC) is optical method for
counting atmospheric aerosol particles.
Earth Science > >
The NOAA Wide Swath Radar Altimeter (WSRA) is an airborne radar system developed by ProSensing. It measures radar backscatter to determine significant wave height, ocean wave spectra, wave topography, and rainfall rate. WSRA is typically flown on NOAA P-3D aircraft for hurricane missions. It operates at 16 GHz and has a sampling rate of 10 Hz. WSRA has a spatial resolution of 5.5-8 km in the along-track direction and 2 km in the across-track direction. It has a total swath width of 3 km.
A dropsondes or dropwindsondes are in situ instruments designed to be released from aircraft. They are equipped with Global Positioning System (GPS) receivers and sensors to collect profile measurements of pressure, temperature, humidity, wind speed, and direction. Dropsondes are important during field investigations because they allow researchers to collect vertical profiles in remote locations and during severe weather events. Dropsondes typically have a vertical resolution of 5 m and provide measurements of wind speed/direction every 0.25 seconds and temperature, pressure, and humidity every 0.5 seconds.
Earth Science > Atmosphere > Atmospheric Temperature
W-band radars are highly sensitive radars used for atmospheric research. They operate around the 94-95 GHz frequency band, allowing for the detection of small water droplets. W-band radars are used for cloud and precipitation studies since they can provide more detailed observations than typical weather radars. They can be deployed on research vessels, aircraft, and mobile ground-based platforms.
The Stepped Frequency Microwave Radiometer (SFMR) is a passive airborne C-band radiometer manufactured by ProSensing Inc. SFMR measures brightness temperature across six frequency bands in the 4.6 to 7.2 GHz range. These measurements can be used to derive rain rates and surface winds. SFMR is typically used for research missions into hurricanes and tropical storms, especially by NOAA’s Hurricane Research Division (HRD). SFMR has a spatial resolution of about 1.5 km and a temporal resolution of about 4 s.
Earth Science > Spectral/engineering > Microwave > Brightness Temperature
The Tail Doppler Radar (TDR) is an airborne vertically scanning, pulse Dopper X-band radar operated by NOAA. It is installed on the tail of the research aircraft and is typically equipped on NOAA’s P-3 aircraft for hurricane and precipitation research missions. TDR measures radar reflectivity and Doppler wind velocities at the 9315 MHz frequency band. It has a horizontal beam width of 1.35 degrees and a range gate spacing of 150 or 300 meters.
The Airborne eXpendable BathyThermograph (AXBT) is an in situ sensor that measures ocean temperature and conductivity. It is deployed from an aircraft using a small parachute and floats to the ocean surface after impact. The floating portion of the instrument then releases a probe into the ocean that collects profile measurements to a depth of about 1000 meters. AXBT has a vertical descent of about 1.5 meters per second.
Sunphotometers are passive optical sensors that measure the amount of sunlight. They are pointed directly at the sun to measure direct sunlight and not sunlight scatter from aerosols. These measurements can be used to determine the aerosol optical depth by following Beer’s Law. Sunphotometers have been deployed on aircraft, research vessels, and field sites for aerosol research and monitoring.
Condensation Particle Counters (CPCs) are in situ sensors that measure aerosol particle concentration. CPCs measure aerosol concentration by condensing fluid onto the particles, allowing them to grow to more detectable sizes for optical scattering. Typically, CPCs can detect particles with a size range of 7 nm-3 μm, can measure particle concentrations up to 100,000 particles/cc, and can provide measurements at 1-second intervals. CPCs are manufactured by TSI Incorporated and can be deployed on airborne, shipborne, and ground-based platforms.
The Scanning ARM Cloud Radar (SACR) is a ground-based Doppler radar system operated by the Department of Energy (DoE) Atmospheric Radiation Measurement (ARM) User Facility. It is a polarimetric Doppler radar consisting of three radar designs at different operating frequencies: X-SACR (9.71 GHz), Ka-SACR (35.3 GHz), and W-SACR (94 GHz). For each deployment location, two SACR radars are deployed with operating frequencies determined by atmospheric attenuation at the site. SACR provides measurements of radar reflectivity, Doppler velocity, spectrum width, and other polarimetric parameters at a gate spacing of 25 meters.
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.
Earth Science > Atmosphere > Atmospheric Water Vapor
Earth Science > Atmosphere > Atmospheric Pressure
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Humidity
Earth Science > Atmosphere > Atmospheric Temperature > Surface Temperature > Air Temperature
The Ka-band ARM Zenith Radar (KAZR) is a ground-based Doppler radar operated by the Department of Energy (DoE) Atmospheric Radiation Measurement (ARM) User Facility. It is a 35 GHz, zenith-pointing radar that provides vertical profiles of clouds by measuring radar reflectivity, Doppler velocity, and spectrum width. KAZR has a beamwidth of 0.3 degrees, a maximum range of 15 kilometers, and a spatial resolution of 30 meters. KAZR is available at several DoE ARM sites and can be deployed for mobile observations.
The microwave radiometers (MWRs) are ground-based radiometers manufactured by Radiometrics Corporation and operated by the Atmospheric Radiation Measurement (ARM) Research Facility. MWR measures brightness temperature at 23.8 and 31.4 GHz to derive column-integrated amounts of water vapor and liquid water in the atmosphere. MWR has a field of view (FOV) from about 5.9 to 4.5 degrees depending on the channel and has a typical time resolution of 20 s for sky-view observations.
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Water Vapor
Earth Science > Spectral/engineering > Microwave > Brightness Temperature
W-band radars are highly sensitive radars used for atmospheric research. They operate around the 94-95 GHz frequency band, allowing for the detection of small water droplets. W-band radars are used for cloud and precipitation studies since they can provide more detailed observations than typical weather radars. They can be deployed on research vessels, aircraft, and mobile ground-based platforms.
The Condensation Nuclei Counter (CNC) is optical method for
counting atmospheric aerosol particles.
Earth Science > >
The Total Sky Imager (TSI) is a ground-based, optical instrument that is manufactured by Yankee Environmental Systems (YES), Inc. TSI can provide full-color, hemispheric images of the sky during the day by using a charge-coupled device (CCD) imager. It also can provide measurements of fractional sky cover and sun obscuration by cloud. TSI can be mounted on mobile platforms such as trailers and research vehicles, allowing it to collect cloud cover measurements in various locations during a field investigation.
The Micropulse Lidar (MPL) is a ground-based lidar system used for cloud detection. It measures lidar backscatter at 532 nm to retrieve cloud properties such as cloud top and base height. It can also be used for the detection of aerosols. MPL has a vertical resolution of 15 m and a maximum range of 18 km. MPL can operate autonomously and typically provides 10-second averaged data.
Earth Science > Spectral/engineering > Lidar > Lidar Depolarization Ratio
Ceilometers are ground-based, remote-sensing sensors that provide measurements of cloud ceilings and vertical visibility. They use either a laser beam or another light source to detect backscatter of clouds, precipitation, and aerosols. Ceilometers can provide detailed and accurate measurements in all types of weather conditions and have low operating costs. Ceilometers are typically used in boundary layer and cloud research applications.
The High Spectral Resolution Lidar (HSRL) is an airborne lidar system developed at NASA Langley Research Center (LaRC). It utilizes 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 have a typical 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 about 6 km. HSRL is typically flown on investigations to validate observations from the CALIPSO spaceborne lidar.
Earth Science > Spectral/engineering > Lidar > Lidar Depolarization Ratio
The Particle Soot Absorption Photometer (PSAP) is an in situ airborne photometer manufactured by Radiance Research. It uses Beer's Law to measure the change in light transmission of aerosol particles. These measurements can be used to derive aerosol absorption and extinction. PSAP operates across three wavelengths (467, 530, and 660 nm) and has a temporal resolution of 1 second. It is typically deployed on aircraft, but it can be deployed on other platforms such as ships and vehicles.
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 at a size resolution of 0.013 mm at 0.2 mm. The TDMA is sometimes combined with an Aerodynamic Particle Sizer (APS) to allow measurements of particles in the submicron range. A typical measurement sequence of TDMA can take approximately 45 minutes to complete.
Nephelometers are in situ airborne or ground-based optical sensors. They measure the total scattering and backscattering of aerosol particles in the atmosphere. Nephelometers operate across three wavelengths: 450 nm, 550 nm, and 700 nm, and have a typical time resolution of 1 Hz.
Radiosondes are a balloon-borne instrument package used to collect profile measurements of pressure, temperature, humidity, and winds. These sensors are connected to a radio transmitter that sends the measurements to a ground receiver typically operating in the 400-406 MHz range. They typically provide measurements at 1-6 seconds, depending on the type and manufacturer of the radiosonde. Radiosondes are used for weather forecasting, ground truth satellite data, atmospheric research, and input for weather prediction models.
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Profiles
Rosemount Pressure Probes are in situ airborne pressure sensors manufactured by Rosemount, Inc. They provide high-precision atmospheric pressure measurements and are typically used to gather flight-level meteorological observations. Rosemount Pressure Probes consist of various pressure transducers, gauges, and multivariable and coplanar transmitters.
Rosemount Temperature Probes are in situ airborne temperature sensors manufactured by Rosemount, Inc. They provide atmospheric temperature measurements and are typically used to collect flight-level meteorological observations. Rosemount Temperature Probes consist of temperature transmitters, thermocouple sensors, resistance temperature detectors, and other temperature sensors.
Earth Science > Atmosphere > Atmospheric Temperature > Upper Air Temperature
Earth Science > Atmosphere > Atmospheric Temperature
The AIMMS - 20 delivers precise real-time meteorological data at rates up to 20Hz. Formed by a combination of four modules: an Inertial Measurement Unit module (IMU) that delivers six degree-of-freedom rate data at 40Hz; a GPS Phase Module that processes satellite navigation signals from two antennas; an Air-Data-Probe (ADP) that measures temperature, humidity, barometric pressure and the aircraft-relative flow vector; and, a Central Processing Module (CPM) to process GPS data, inertial signals and air-data information that yield accurate wind data when combined.
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Humidity > Relative Humidity
Earth Science > Atmosphere > Atmospheric Temperature > Surface Temperature > Air Temperature
Earth Science > Atmosphere > Air Quality
This data will be added in future versions
Earth Science > >
The Cloud Droplet Probe (CDP) is an in situ cloud probe manufactured by Droplet Measurement Technologies. It measures the particle size distribution and concentration for cloud particles in the 2-50 μm size range. CDP detects pulses of light scattered from a laser (658 nm) to count and size individual cloud droplets. CDP has a typical measurement rate of 1 Hz and can detect concentrations of up to 2000 particles per cubic centimeter.
The Counterflow Virtual Impactor (CVI) is an in situ airborne instrument that samples cloud droplets. It samples cloud droplets by removing them from the surrounding air through inertial impaction. CVI is typically deployed with additional sensors to provide measurements of cloud particle concentration, cloud liquid water, and water vapor of the sample droplets. CVI can detect cloud droplets as small as 7 microns in diameter and has a typical time response of 1 second.
Condensation Particle Counters (CPCs) are in situ sensors that measure aerosol particle concentration. CPCs measure aerosol concentration by condensing fluid onto the particles, allowing them to grow to more detectable sizes for optical scattering. Typically, CPCs can detect particles with a size range of 7 nm-3 μm, can measure particle concentrations up to 100,000 particles/cc, and can provide measurements at 1-second intervals. CPCs are manufactured by TSI Incorporated and can be deployed on airborne, shipborne, and ground-based platforms.
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.
Earth Science > Atmosphere > Atmospheric Water Vapor
Earth Science > Atmosphere > Atmospheric Pressure
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Humidity
Earth Science > Atmosphere > Atmospheric Temperature > Surface Temperature > Air Temperature
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 Passive-Cavity Aerosol Spectrometer Probe (PCASP) is an in situ airborne optical spectrometer manufactured by Droplet Measurement Technologies. It measures the light scattered by particles to determine the aerosol size distribution and concentration in the 0.1 to 3.0 μm size range. PCASP operates at the 632 nm wavelength and has a typical sampling rate of 10 Hz.
The Particule Volume Matter (PVM-100A) is an in situ airborne cloud probe manufactured by Gerber Scientific. It measures liquid water content and the effective radius of cloud droplets by measuring the scattering intensity proportional to the droplets' density and particle surface area density. PVM-100A operates at 780 nm and has a measurement rate of up to 5000 Hz. It can measure droplets in the size range of 3-50 μm diameter. The ground-based model of this instrument is PVM-100.
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 one instrument. CAPS measures the size distribution of aerosol, cloud, and liquid droplets for particles between the sizes of 50-1600 μm at a time resolution of 1 Hz. It can also record images of cloud particles and provide measurements of temperature, pressure, and LWC.
A Tunable Diode Laser Absorption Spectrometer (TDLAS) is an airborne or ground-based in situ optical spectrometer. TDLAS measures the wavelength-dependent absorption of light to determine the concentration of various trace gases. It can also determine the gas species' temperature, pressure, velocity, and mass flux when possible. TDLAS has a typical time resolution of 1 second.
The High Volume Precipitation Spectrometer 3 (HVPS-3) is an in situ airborne particle imager manufactured by SPEC Inc. It uses a 128-photodiode array to provide imagery of precipitation particles. The imagery can be used to determine the shape, size, and concentration of the particles. HVPS-3 has a pixel resolution of 150 μm and a maximum field of view of 1.92 cm.
The Ultra-High Sensitivity Aerosol Spectrometer (UHSAS) is an in situ spectrometer manufactured by Droplet Measurement Technologies. It can be utilized on both airborne and ground-based platforms to measure aerosol size distribution and concentration. UHSAS determines the particle size by detecting the peak light signals of the aerosol particles which are illuminated by a 1054 nm laser. UHSAS can sample particles within the 60 - 1000 nm size range and has a sampling frequency of 10 Hz.
The Single Particle Soot Photometer (SP2) is a laser-induced photometer manufactured by Droplet Measurement Technologies. SP2 provides measurements of the black carbon (BC) mass content of individual aerosol particles as well as the optical and physical properties of the particles containing BC. SP2 can be utilized on airborne or ground-based platforms and can be deployed with a paired Humidified-Dual SP2 (HD-SP2). It can detect aerosol particles with a diameter size of 200-400 nm and can measure 25,000 particles/second.
The Condensation Nuclei Counter (CNC) is optical method for
counting atmospheric aerosol particles.
Earth Science > >
The SEA Model WCM-2000 Multi Element Water Content System (WCM-2000) is an in situ airborne sensor manufactured by Science Engineering Associates (SEA), Inc. It directly measures liquid water content (LWC) and total water content (TWC) within clouds. It can also be used to derive ice water content (IWC). WCM-2000 measures LWC and TWC in the range of 0 to 10 grams per cubic meter. It has a typical data rate of 1 Hz.
The Cloud Imaging Probe (CIP) is an in situ airborne optical array probe manufactured by Droplet Measurement Technologies. CIP records cloud particle images by capturing the shadow of the particles as they pass through the laser. It also provides information on the particle size distribution and cloud liquid water content. CIP has a typical resolution of 25 μm and can measure particles in the size range of 12.5 μm - 1.55 mm.
The Cloud Spectrometer and Impactor (CSI) is an in situ airborne probe that measures total condensed water (TCW) content in clouds. It consists of a combination of a counterflow virtual impactor (CVI) and a lightweight cloud droplet probe. It can measure cloud particles in the size range of 2 to 50 μm and has a typical sampling frequency of 1 second.
The Fast Cloud Droplet Probe (FCDP) is an in-situ airborne cloud probe manufactured by SPEC Inc. FCDP measures the concentration and size of cloud droplets by detecting the amount of light scattered by the particles. It measures particles within the diameter size range of 1.5-50 microns and has a typical measurement frequency of 1 Hz.
The 2D-Stereo Particle Probe (2D-S) is an in situ airborne optical imaging probe developed by SPEC Inc. The 2D-S uses two diode laser beams to produce stereo cloud particle images through linear array shadowing. Through the imagery, cloud particle size distribution, particle number concentration, and ice/liquid water content can be determined. It has a resolution of 10 µm and can measure hydrometeors in the 25-1280 µm range.
The Particle Soot Absorption Photometer (PSAP) is an in situ airborne photometer manufactured by Radiance Research. It uses Beer's Law to measure the change in light transmission of aerosol particles. These measurements can be used to derive aerosol absorption and extinction. PSAP operates across three wavelengths (467, 530, and 660 nm) and has a temporal resolution of 1 second. It is typically deployed on aircraft, but it can be deployed on other platforms such as ships and vehicles.
Nephelometers are in situ airborne or ground-based optical sensors. They measure the total scattering and backscattering of aerosol particles in the atmosphere. Nephelometers operate across three wavelengths: 450 nm, 550 nm, and 700 nm, and have a typical time resolution of 1 Hz.
The Cloud and Aerosol Spectrometer (CAS) is an in situ airborne spectrometer manufactured by Droplet Measurement Technologies. It measures light scattering at 658 nm to determine aerosol and cloud particle size distributions from 0.51 to 50 μm. It also provides measurements of the refractive index and particle shape. CAS has a typical time resolution of 1 Hz and can measure concentrations greater than 1,000 particles per cubic meter.
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.
