The Investigation of Microphysics and Precipitation for Atlantic Coast-Threatening Snowstorms (IMPACTS) was a NASA-led campaign that mainly focused on how snow bands form and develop in the eastern United States. IMPACTS included three deployments during the 2020, 2022, and 2023 winter seasons. NASA’s ER-2, equipped with various remote sensing instruments like the ER-2 X-band Doppler Radar (EXRAD) and the Conical Scanning Microwave Imaging Radiometer (CoSMIR), along with NASA’s P-3 aircraft, which had in situ sensors such as the Cloud-Aerosol Precipitation Scatterometer (CAPS) and Airborne Vertical Atmospheric Profiling System (AVAPS) dropsondes, flew routes to sample frontal systems and their associated snow bands across the Eastern and Midwestern United States. Aircraft measurements were complemented by ground instruments such as rawinsondes launched by NOAA and several universities, rain gauge systems, and the Micro Rain Radar (MRR). IMPACTS was part of NASA’s Earth Venture Suborbital-3 (EVS-3) projects.
Ceilometers are ground-based remote sensing sensors that measure cloud ceilings and vertical visibility. They utilize a laser or another light source to detect backscatter from clouds, precipitation, and aerosols. Ceilometers provide detailed and precise measurements under all weather conditions and are cost-effective to operate. They are commonly used in boundary layer and cloud research.
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 Two-Dimensional Video Disdrometer (2DVD) is a stationary, ground-based optical disdrometer. It features two line-scan cameras that continuously measure various precipitation properties such as droplet shape, fall velocity, and size distribution. The 2DVD accurately measures all precipitation particles with a diameter greater than 0.2 mm, making it ideal for different precipitation studies.
The Autonomous Parsivel Unit (APU) is an in situ ground-based optical disdrometer. APU measures the size and fall velocity of hydrometeors with a range of 0-25 mm in size and 0-20 m/s in fall speed. Using these measurements, the drop size distribution, type, intensity, and amount of precipitation can be determined. APU operates in the 650-780 nm wavelength range and typically samples every 10 seconds.
Pluvio is a ground-based weighing precipitation gauge manufactured by OTT HydroMet. It measures precipitation amount and rate by determining its weight using a high-capacity collection bucket. Pluvio can measure rain, snow, sleet, hail, and mixed precipitation types. It has a standard sampling interval of 1 minute and an accuracy of ± 0.05 to 0.1 mm.
The Micro Rain Radar (MRR) is a ground-based, vertically oriented, continuous wave K-band (24.23 GHz) radar that measures various parameters of precipitation, such as liquid water content and rain rate, from near ground level to the lower troposphere. The backscatter captured by the MRR’s antenna can determine precipitation size distributions ranging from 0.25 mm to 4.53 mm and can also calculate the frequency shift of falling precipitation to determine its velocity. Additional uses of the MRR include identifying bright bands, nowcasting precipitation, and tracking chemical transport during precipitation events. It has a range resolution of 10 to 200 meters and a sampling time of 10 seconds.
The NASA S-band Dual Polarimetric Radar (NPOL) is a portable, ground-based scanning dual-polarimetric Doppler radar. As an active remote sensor, NPOL detects reflected electromagnetic waves to determine radar reflectivity, Doppler velocity, rainfall rate, particle size distribution, water content, and precipitation type. Normally, NPOL has a beamwidth of 0.95°, a gate spacing of 0.15 km, and a maximum range of 150 km. It is operationally comparable to Doppler radars used by the U.S. National Weather Service’s Next Generation Weather Radar (NEXRAD) network, but NPOL has the benefit of being fully deployable.
The Ka-band Scanning Polarimetric Radar (KASPR) is a ground-based polarimetric Doppler radar at the Stony Brook University (SBU) Radar Observatory. It is a 35.29 GHz radar that measures reflectivity, Doppler velocity, and other polarimetric radar observations to characterize clouds and precipitation. KASPR has a beamwidth of 0.32 degrees and a range resolution of 15 to 200 meters.
The SBU Doppler Lidar is a ground-based lidar system operated by Stony Brook University (SBU). It is a Doppler lidar manufactured by Halo Photonics that provides measurements of Doppler velocity, attenuated backscatter, and signal-to-noise ratio (SNR). It operates in the near-infrared (1.5 μm) and is sensitive to micron-sized aerosol backscatter. It can collect measurements up to 12 km and has a range gate of 18 to 60 m. The SBU Doppler Lidar has a temporal resolution ranging from 0.1 to 30 seconds.
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 determine the column amounts of water vapor and liquid water in the atmosphere. MWR has a field of view (FOV) ranging from about 5.9 to 4.5 degrees depending on the channel and typically has a time resolution of 20 seconds for sky-view observations.
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Water Vapor
Earth Science > Spectral/engineering > Microwave > Brightness Temperature
Earth Science > Atmosphere > Atmospheric Water Vapor
ROGER is a ground-based W-band frequency modulated continuous wave (FMCW) profiling radar operating at Stony Brook – Brookhaven Radar Observatory (SBRO). It was originally developed by ProSensing as an airborne radar system before being converted for ground-based operations. It collects radar measurements at an operating frequency of 94.8 GHz. ROGER has a range resolution of 5-150 m and can detect targets up to 20 km.
The Dual-frequency Dual-polarized Doppler Radar (D3R) is a mobile Ku-/Ka-band radar that was developed for NASA’s Global Precipitation Measurement (GPM) mission Ground The Dual-frequency Dual-polarized Doppler Radar (D3R) is a mobile Ku-/Ka-band radar developed for NASA’s Global Precipitation Measurement (GPM) mission Ground Validation (GV) program. D3R measures radar backscatter to provide reflectivity, Doppler velocity, differential reflectivity, correlation coefficient, and other radar observations. These measurements help derive droplet size distribution and identify hydrometer types. D3R has a beam width of approximately 0.9 degrees, a maximum range of 30 km, and a gate spacing of 150 m. It operates at wavelengths similar to the Dual-frequency Precipitation Radar (DPR) on the GPM Core satellite and can be used to validate DPR observations.
The Precipitation and Imaging Probe (PIP) is an airborne optical spectrometer developed by Droplet Measurement Technologies. It measures the size and shape of particles ranging from 100 to 6200 μm. It provides two-dimensional images with a pixel resolution of 100 μm. PIP operates at a wavelength of 660 nm and typically samples every second. It has a sample area of 260 mm by 6.2 mm and can function at airspeeds of 10 to 200 meters per second.
Ceilometers are ground-based remote sensing sensors that measure cloud ceilings and vertical visibility. They utilize a laser or another light source to detect backscatter from clouds, precipitation, and aerosols. Ceilometers provide detailed and precise measurements under all weather conditions and are cost-effective to operate. They are commonly used in boundary layer and cloud research.
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 Autonomous Parsivel Unit (APU) is an in situ ground-based optical disdrometer. APU measures the size and fall velocity of hydrometeors with a range of 0-25 mm in size and 0-20 m/s in fall speed. Using these measurements, the drop size distribution, type, intensity, and amount of precipitation can be determined. APU operates in the 650-780 nm wavelength range and typically samples every 10 seconds.
The SBU X-band Phased Array Radar (SKYLER) is a ground-based Doppler radar located at the Stony Brook University (SBU) Radar Observatory. It is operated by the SBU School of Marine and Atmospheric Sciences and has been integrated into mobile platforms for weather research since 2019. SKYLER is an X-band (9.25 GHz) polarimetric radar that measures radar reflectivity, Doppler velocity, spectrum width, and other radar parameters. It has a beamwidth of 1.98 degrees and a spatial resolution of 5 to 10 meters.
The Micro Rain Radar (MRR) is a ground-based, vertically oriented, continuous wave K-band (24.23 GHz) radar that measures various parameters of precipitation, such as liquid water content and rain rate, from near ground level to the lower troposphere. The backscatter captured by the MRR’s antenna can determine precipitation size distributions ranging from 0.25 mm to 4.53 mm and can also calculate the frequency shift of falling precipitation to determine its velocity. Additional uses of the MRR include identifying bright bands, nowcasting precipitation, and tracking chemical transport during precipitation events. It has a range resolution of 10 to 200 meters and a sampling time of 10 seconds.
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 Hawkeye Combination Cloud Particle Probe is an in situ airborne probe developed by SPEC, Inc. It was initially designed to be flown on NASA’s Global Hawk Uncrewed Aerial Vehicle (UAV). Hawkeye includes four probes: the Fast Cloud Droplet Probe (FCDP), a 10-micron channel 2D-S Probe, a 50-micron channel 2D-S Probe, and a Cloud Particle Imager (CPI). Hawkeye captures images of cloud particles and measures particle size distribution and concentration. The FCDP has a size range of 1.5 to 50 μm with a resolution of 3 μm. The 10-micron channel 2D-S probe covers a size range of 10 to 1280 μm, while the 50-micron channel 2D-S covers 50 to 6400 μm. The CPI provides a resolution of 2.3 μm, a size range from 2.3 to 2300 μm, and a frame rate up to 400 frames per second.
The Nezorov Probe is an in situ airborne hot-wire probe that measures clouds' liquid water content (LWC) and total water content (TWC). It determines LWC and TWC by detecting heat loss from its two sensors caused by evaporation of cloud water and convective heat losses. Operating at a constant temperature of 90 degrees Celsius, it can measure LWC and TWC in the range of 0.005-3 grams per cubic meter. The Nevzorov Probe provides measurements every second with an accuracy of 10%.
The King Probe is an in situ airborne cloud instrument developed by Warren King (Commonwealth Scientific and Industrial Research Organisation) and manufactured by Particle Measuring Systems (PMS) and Droplet Measurement Technologies (DMT). The King Probe measures cloud liquid water content (LWC) by detecting the heat released when water droplets vaporize. It operates at a constant temperature of approximately 100°C and has a data output rate of 1 to 10 Hz. The probe is commonly used in studies of cloud microphysics and aircraft icing.
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 2D-Stereo Particle Probe (2D-S) is an in situ airborne optical imaging device developed by SPEC Inc. It uses two diode laser beams to create stereo images of cloud particles via linear array shadowing. These images allow for the determination of cloud particle size distribution, particle number concentration, and ice or liquid water content. 2D-S has a resolution of 10 µm and can measure hydrometeors ranging from 25 to 1280 µm.
The Airborne Vertical Atmospheric Profiling System (AVAPS) is an airborne system that uses dropsondes and Global Positioning System (GPS) receivers to gather in situ profiles of atmospheric parameters. It provides profile measurements of temperature, pressure, and humidity every 0.5 seconds, and atmospheric wind measurements every 0.25 seconds. AVAPS has a vertical resolution of approximately 10 meters and can launch dropsondes every 20 seconds. Developed by the National Center for Atmospheric Research (NCAR) for the NASA Global Hawk, it can also be deployed on other aircraft such as the DC-8 and P-3.
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Humidity
Earth Science > Atmosphere > Atmospheric Temperature
The High Volume Precipitation Spectrometer (HVPS) is an in situ airborne particle imager manufactured by SPEC Inc. It uses a 128-photodiode array to capture images of precipitation particles. These images can be used to determine the particles' shape, size, and concentration. HVPS-3 has a pixel resolution of 150 μm and a maximum field of view of 1.92 cm.
The Rosemount Icing Detector (RICE) is an in-situ airborne probe developed by Rosemount Inc. It uses magnetostrictive oscillation to detect shifts in frequency caused by ice accumulation on the sensing cylinder. These frequency changes correlate with the rate of ice buildup, which helps determine liquid water content. RICE typically samples every second.
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 Turbulent Air Motion Measurement System (TAMMS) is an in situ airborne sensor used to gather aircraft navigation information. TAMMS consists of several subsystems, including pressure transducers and temperature sensors, an aircraft inertial navigation system, a central data acquisition system, and water vapor and other gas sensors. It provides measurements of aircraft position, flight level winds, temperature, pressure, and water vapor. TAMMS has a typical sampling frequency of less than 1 second and a spatial resolution of 5 meters.
Earth Science > Atmosphere > Atmospheric Temperature
Earth Science > Atmosphere > Atmospheric Winds
The Particle Habit Imaging and Polar Scattering (PHIPS) probe is an in situ airborne cloud probe used to analyze particle shape, size, and habit. It features a high-resolution stereomicroscopic imager and a single-particle polar nephelometer. The particle imager captures images of the same cloud particle from two different angles at a resolution of 2 μm. The nephelometer measures light scattering of single particles across 20 angles from 18 to 170 degrees, with an angular resolution of 1 degree for forward scattering and 8 degrees for side and backscattering. PHIPS can measure particle sizes ranging from 50 to 700 μm for ice particles and 100 to 700 μm for water droplets. It has a field of view of approximately 3 x 2 mm and a sampling frequency of 0.7 seconds.
The Water Isotope System for Precipitation and Entrainment Research (WISPER) is an in situ airborne instrument used to measure condensed water content and water vapor. It consists of two inlets with the primary inlet being a counterflow virtual impactor (CVI) used to collect air samples. Picarro cavity ringdown laser spectrometers (CRDS) are used to measure condensed water and water vapor within the air samples. WISPER can also provide water vapor isotopic abundances. It has a typical sampling frequency of 1 second.
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Water Vapor
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators
Earth Science > Atmosphere > Atmospheric Water Vapor
The Conical Scanning Millimeter-wave Imaging Radiometer (CoSMIR) is an airborne imaging radiometer designed to validate the Special Sensor Microwave Imager/Sounder (SSMIS) instrument. CoSMIR operates across nine spectral channels in the 50-183 GHz range to measure microwave brightness temperature. It has a surface footprint resolution of 1.4 km by 1.4 km at an altitude of 20 km at nadir. CoSMIR can perform both conical and cross-tracking scanning.
Earth Science > Spectral/engineering > Microwave > Brightness Temperature
The Cloud Radar System (CRS) is an airborne W-band (94 GHz) polarimetric Doppler radar designed for the NASA ER-2 aircraft. CRS provides radar observations of clouds and precipitation from the surface to the lower stratosphere. It has a horizontal resolution of 150 m and a horizontal sampling interval of 50 m. Its vertical resolution is 100 m with a vertical sampling interval of 37.5 m.
The Lightning Instrument Package (LIP) is an in situ airborne system that detects electric fields. LIP uses eight electric field mills and a conductivity probe to measure the three-dimensional components of electric fields in thunderstorms around it. LIP has a sampling frequency of 0.02 seconds and an accuracy of 2.5%.
Earth Science > Atmosphere > Atmospheric Electricity > Electric Field
The ER-2 X-Band Doppler Radar (EXRAD) is a dual-beam, X-band radar mounted on NASA’s ER-2 aircraft. It was initially intended to be used on the Global Hawk but was instead developed for the ER-2 to replace the ER-2 Doppler Radar (EDOP). EXRAD measures backscatter to determine radar reflectivity, Doppler velocity, and linear depolarization ratio. These measurements help to analyze the phase, orientation, size, and other properties of precipitation particles. EXRAD operates at 9.6 GHz and has a range resolution between 37.5 and 300 meters. It has a swath width of 28 km at an altitude of 20 km during scanning mode, with a typical sampling frequency of 0.25 seconds.
The Advanced Microwave Precipitation Radiometer (AMPR) is an airborne passive microwave radiometer. AMPR provides calibrated brightness temperatures, which can be used to determine cloud and precipitation characteristics. It operates across four microwave channels: 10.7, 19.35, 37.1, and 85.5 GHz. These frequencies are sensitive to precipitation, making AMPR well-suited for studying rain events. It has a surface footprint size ranging from 640 m (85.5 GHz) to 2.8 km (10.7 GHz).
Earth Science > Spectral/engineering > Microwave > Brightness Temperature
The High-Altitude Wind and Rain Airborne Profiler (HIWRAP) is an airborne Ka- and Ku-band, dual-beam Doppler radar system. It measures radar reflectivity and 3-D wind fields within clouds and precipitation, making it ideal for research missions into hurricanes and severe storms. It was designed to operate at higher altitudes (~ 20 km) than previous airborne wind profilers, allowing for a better vertical profile of the troposphere. HIWRAP has a range resolution of 150 m and operates at the following frequencies: 13.5 GHz, 13.9 GHz, 33.7 GHz, and 35.6 GHz.
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 at three wavelengths: 355 nm, 532 nm, and 1064 nm. These measurements can be used to determine 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. It has a measurement sampling rate 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
The Next Generation Weather Radar (NEXRAD) is a network of high-resolution, S-band radars operated by the National Weather Service (NWS), the Federal Aviation Administration (FAA), and the United States Air Force. NEXRAD measures the magnitude of the returned energy to provide reflectivity, velocity, and spectrum width observations, which can be processed to create mosaic maps of precipitation. NEXRAD radars typically operate with a 0.9-degree beamwidth, 0.25 to 1 km spatial resolution, and a maximum range of 230 to 460 km. Currently, over 160 NEXRAD radars are operating across the United States and some overseas locations.
The New York State (NYS) Mesonet is a ground-based network operated by the University at Albany. It has 127 weather stations, with at least one in each county and borough. Each station records temperature, humidity, wind speed and direction, pressure, solar radiation, precipitation, and soil data in real-time every 5 minutes. The NYS Mesonet also includes several sub-networks, such as a Profiler Network with 17 sites for remote sensing atmospheric observations, a Flux Network with 17 sites for monitoring surface energy, and a Snow Network with 20 sites for measuring snow water content.
Earth Science > Land Surface > Soils > Soil 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 Hawkeye Combination Cloud Particle Probe is an in situ airborne probe developed by SPEC, Inc. It was initially designed to be flown on NASA’s Global Hawk Uncrewed Aerial Vehicle (UAV). Hawkeye includes four probes: the Fast Cloud Droplet Probe (FCDP), a 10-micron channel 2D-S Probe, a 50-micron channel 2D-S Probe, and a Cloud Particle Imager (CPI). Hawkeye captures images of cloud particles and measures particle size distribution and concentration. The FCDP has a size range of 1.5 to 50 μm with a resolution of 3 μm. The 10-micron channel 2D-S probe covers a size range of 10 to 1280 μm, while the 50-micron channel 2D-S covers 50 to 6400 μm. The CPI provides a resolution of 2.3 μm, a size range from 2.3 to 2300 μm, and a frame rate up to 400 frames per second.
The Water Isotope System for Precipitation and Entrainment Research (WISPER) is an in situ airborne instrument used to measure condensed water content and water vapor. It consists of two inlets with the primary inlet being a counterflow virtual impactor (CVI) used to collect air samples. Picarro cavity ringdown laser spectrometers (CRDS) are used to measure condensed water and water vapor within the air samples. WISPER can also provide water vapor isotopic abundances. It has a typical sampling frequency of 1 second.
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Water Vapor
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators
Earth Science > Atmosphere > Atmospheric Water Vapor
The King Probe is an in situ airborne cloud instrument developed by Warren King (Commonwealth Scientific and Industrial Research Organisation) and manufactured by Particle Measuring Systems (PMS) and Droplet Measurement Technologies (DMT). The King Probe measures cloud liquid water content (LWC) by detecting the heat released when water droplets vaporize. It operates at a constant temperature of approximately 100°C and has a data output rate of 1 to 10 Hz. The probe is commonly used in studies of cloud microphysics and aircraft icing.
The Particle Habit Imaging and Polar Scattering (PHIPS) probe is an in situ airborne cloud probe used to analyze particle shape, size, and habit. It features a high-resolution stereomicroscopic imager and a single-particle polar nephelometer. The particle imager captures images of the same cloud particle from two different angles at a resolution of 2 μm. The nephelometer measures light scattering of single particles across 20 angles from 18 to 170 degrees, with an angular resolution of 1 degree for forward scattering and 8 degrees for side and backscattering. PHIPS can measure particle sizes ranging from 50 to 700 μm for ice particles and 100 to 700 μm for water droplets. It has a field of view of approximately 3 x 2 mm and a sampling frequency of 0.7 seconds.
The High Altitude Lidar Observatory (HALO) is an airborne lidar system developed by NASA's Langley Research Center. HALO operates on four wavelengths (1645, 1064, 935, 532 nm) and combines Differential Absorption Lidar (DIAL) with High Spectral Resolution Lidar (HSRL) techniques to measure lidar backscatter and depolarization ratio. It provides vertical profiles of aerosol and cloud optical properties, atmospheric water vapor, and methane at a data rate of 2 Hz. HALO has a nominal spatial resolution of 12 km horizontally and 315 m vertically at an altitude of 10 km.
Earth Science > Spectral/engineering > Lidar > Lidar Depolarization Ratio
The 2D-Stereo Particle Probe (2D-S) is an in situ airborne optical imaging device developed by SPEC Inc. It uses two diode laser beams to create stereo images of cloud particles via linear array shadowing. These images allow for the determination of cloud particle size distribution, particle number concentration, and ice or liquid water content. 2D-S has a resolution of 10 µm and can measure hydrometeors ranging from 25 to 1280 µm.
The Airborne Vertical Atmospheric Profiling System (AVAPS) is an airborne system that uses dropsondes and Global Positioning System (GPS) receivers to gather in situ profiles of atmospheric parameters. It provides profile measurements of temperature, pressure, and humidity every 0.5 seconds, and atmospheric wind measurements every 0.25 seconds. AVAPS has a vertical resolution of approximately 10 meters and can launch dropsondes every 20 seconds. Developed by the National Center for Atmospheric Research (NCAR) for the NASA Global Hawk, it can also be deployed on other aircraft such as the DC-8 and P-3.
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Humidity
Earth Science > Atmosphere > Atmospheric Temperature
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 Vapor Inside-cloud Profiling Radar (VIPR) is an airborne differential absorption radar developed at the Jet Propulsion Laboratory (JPL). It retrieves absolute humidity inside clouds and precipitation and column-integrated water vapor profiles. It operates across the three frequencies in the G-band: 158.6, 167.12, and 174.74 GHz. VIPR provides water vapor profiles every 1.9 seconds and has a nominal range resolution of 15 meters.
Earth Science > Atmosphere > Atmospheric Water Vapor
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Humidity > Absolute Humidity
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Water Vapor
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Profiles
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Humidity
Earth Science > Spectral/engineering > Radar
The High Volume Precipitation Spectrometer (HVPS) is an in situ airborne particle imager manufactured by SPEC Inc. It uses a 128-photodiode array to capture images of precipitation particles. These images can be used to determine the particles' shape, size, and concentration. HVPS-3 has a pixel resolution of 150 μm and a maximum field of view of 1.92 cm.
The Rosemount Icing Detector (RICE) is an in-situ airborne probe developed by Rosemount Inc. It uses magnetostrictive oscillation to detect shifts in frequency caused by ice accumulation on the sensing cylinder. These frequency changes correlate with the rate of ice buildup, which helps determine liquid water content. RICE typically samples every second.
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 Turbulent Air Motion Measurement System (TAMMS) is an in situ airborne sensor used to gather aircraft navigation information. TAMMS consists of several subsystems, including pressure transducers and temperature sensors, an aircraft inertial navigation system, a central data acquisition system, and water vapor and other gas sensors. It provides measurements of aircraft position, flight level winds, temperature, pressure, and water vapor. TAMMS has a typical sampling frequency of less than 1 second and a spatial resolution of 5 meters.
Ceilometers are ground-based remote sensing sensors that measure cloud ceilings and vertical visibility. They utilize a laser or another light source to detect backscatter from clouds, precipitation, and aerosols. Ceilometers provide detailed and precise measurements under all weather conditions and are cost-effective to operate. They are commonly used in boundary layer and cloud research.
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 Two-Dimensional Video Disdrometer (2DVD) is a stationary, ground-based optical disdrometer. It features two line-scan cameras that continuously measure various precipitation properties such as droplet shape, fall velocity, and size distribution. The 2DVD accurately measures all precipitation particles with a diameter greater than 0.2 mm, making it ideal for different precipitation studies.
The Autonomous Parsivel Unit (APU) is an in situ ground-based optical disdrometer. APU measures the size and fall velocity of hydrometeors with a range of 0-25 mm in size and 0-20 m/s in fall speed. Using these measurements, the drop size distribution, type, intensity, and amount of precipitation can be determined. APU operates in the 650-780 nm wavelength range and typically samples every 10 seconds.
The Precipitation and Imaging Probe (PIP) is an airborne optical spectrometer developed by Droplet Measurement Technologies. It measures the size and shape of particles ranging from 100 to 6200 μm. It provides two-dimensional images with a pixel resolution of 100 μm. PIP operates at a wavelength of 660 nm and typically samples every second. It has a sample area of 260 mm by 6.2 mm and can function at airspeeds of 10 to 200 meters per second.
The Micro Rain Radar (MRR) is a ground-based, vertically oriented, continuous wave K-band (24.23 GHz) radar that measures various parameters of precipitation, such as liquid water content and rain rate, from near ground level to the lower troposphere. The backscatter captured by the MRR’s antenna can determine precipitation size distributions ranging from 0.25 mm to 4.53 mm and can also calculate the frequency shift of falling precipitation to determine its velocity. Additional uses of the MRR include identifying bright bands, nowcasting precipitation, and tracking chemical transport during precipitation events. It has a range resolution of 10 to 200 meters and a sampling time of 10 seconds.
The NASA S-band Dual Polarimetric Radar (NPOL) is a portable, ground-based scanning dual-polarimetric Doppler radar. As an active remote sensor, NPOL detects reflected electromagnetic waves to determine radar reflectivity, Doppler velocity, rainfall rate, particle size distribution, water content, and precipitation type. Normally, NPOL has a beamwidth of 0.95°, a gate spacing of 0.15 km, and a maximum range of 150 km. It is operationally comparable to Doppler radars used by the U.S. National Weather Service’s Next Generation Weather Radar (NEXRAD) network, but NPOL has the benefit of being fully deployable.
Pluvio is a ground-based weighing precipitation gauge manufactured by OTT HydroMet. It measures precipitation amount and rate by determining its weight using a high-capacity collection bucket. Pluvio can measure rain, snow, sleet, hail, and mixed precipitation types. It has a standard sampling interval of 1 minute and an accuracy of ± 0.05 to 0.1 mm.
Digital cameras are used to provide imagery for research applications. Cameras are used on aircraft to collect aerial imagery for mapping and surveying, environmental monitoring, cloud observations, agriculture, geological studies, and other Earth science applications. They are also used at field sites to capture visual observations to monitor changes in land cover, vegetation, clouds, air quality, glaciers, and other phenomena.
The Cloud Radar System (CRS) is an airborne W-band (94 GHz) polarimetric Doppler radar designed for the NASA ER-2 aircraft. CRS provides radar observations of clouds and precipitation from the surface to the lower stratosphere. It has a horizontal resolution of 150 m and a horizontal sampling interval of 50 m. Its vertical resolution is 100 m with a vertical sampling interval of 37.5 m.
The Lightning Instrument Package (LIP) is an in situ airborne system that detects electric fields. LIP uses eight electric field mills and a conductivity probe to measure the three-dimensional components of electric fields in thunderstorms around it. LIP has a sampling frequency of 0.02 seconds and an accuracy of 2.5%.
Earth Science > Atmosphere > Atmospheric Electricity > Electric Field
The ER-2 X-Band Doppler Radar (EXRAD) is a dual-beam, X-band radar mounted on NASA’s ER-2 aircraft. It was initially intended to be used on the Global Hawk but was instead developed for the ER-2 to replace the ER-2 Doppler Radar (EDOP). EXRAD measures backscatter to determine radar reflectivity, Doppler velocity, and linear depolarization ratio. These measurements help to analyze the phase, orientation, size, and other properties of precipitation particles. EXRAD operates at 9.6 GHz and has a range resolution between 37.5 and 300 meters. It has a swath width of 28 km at an altitude of 20 km during scanning mode, with a typical sampling frequency of 0.25 seconds.
The Advanced Microwave Precipitation Radiometer (AMPR) is an airborne passive microwave radiometer. AMPR provides calibrated brightness temperatures, which can be used to determine cloud and precipitation characteristics. It operates across four microwave channels: 10.7, 19.35, 37.1, and 85.5 GHz. These frequencies are sensitive to precipitation, making AMPR well-suited for studying rain events. It has a surface footprint size ranging from 640 m (85.5 GHz) to 2.8 km (10.7 GHz).
Earth Science > Spectral/engineering > Microwave > Brightness Temperature
The High-Altitude Wind and Rain Airborne Profiler (HIWRAP) is an airborne Ka- and Ku-band, dual-beam Doppler radar system. It measures radar reflectivity and 3-D wind fields within clouds and precipitation, making it ideal for research missions into hurricanes and severe storms. It was designed to operate at higher altitudes (~ 20 km) than previous airborne wind profilers, allowing for a better vertical profile of the troposphere. HIWRAP has a range resolution of 150 m and operates at the following frequencies: 13.5 GHz, 13.9 GHz, 33.7 GHz, and 35.6 GHz.
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 at three wavelengths: 355 nm, 532 nm, and 1064 nm. These measurements can be used to determine 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. It has a measurement sampling rate of 1 Hz.
The Configurable Scanning Submillimeter-wave Instrument/Radiometer (CoSSIR) is an airborne imaging radiometer designed to measure ice clouds. It measures brightness temperature across 16 channels in the 183-874 GHz range. These measurements can determine ice cloud properties, water vapor profiles, and snowfall rates. CoSSIR has a surface footprint of 1.5 km at nadir at an altitude of 20 km. It has a scan cycle of 4.6 seconds.
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Profiles
Earth Science > Spectral/engineering > Microwave > Brightness Temperature
The Hawkeye Combination Cloud Particle Probe is an in situ airborne probe developed by SPEC, Inc. It was initially designed to be flown on NASA’s Global Hawk Uncrewed Aerial Vehicle (UAV). Hawkeye includes four probes: the Fast Cloud Droplet Probe (FCDP), a 10-micron channel 2D-S Probe, a 50-micron channel 2D-S Probe, and a Cloud Particle Imager (CPI). Hawkeye captures images of cloud particles and measures particle size distribution and concentration. The FCDP has a size range of 1.5 to 50 μm with a resolution of 3 μm. The 10-micron channel 2D-S probe covers a size range of 10 to 1280 μm, while the 50-micron channel 2D-S covers 50 to 6400 μm. The CPI provides a resolution of 2.3 μm, a size range from 2.3 to 2300 μm, and a frame rate up to 400 frames per second.
The Water Isotope System for Precipitation and Entrainment Research (WISPER) is an in situ airborne instrument used to measure condensed water content and water vapor. It consists of two inlets with the primary inlet being a counterflow virtual impactor (CVI) used to collect air samples. Picarro cavity ringdown laser spectrometers (CRDS) are used to measure condensed water and water vapor within the air samples. WISPER can also provide water vapor isotopic abundances. It has a typical sampling frequency of 1 second.
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Water Vapor
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators
Earth Science > Atmosphere > Atmospheric Water Vapor
The King Probe is an in situ airborne cloud instrument developed by Warren King (Commonwealth Scientific and Industrial Research Organisation) and manufactured by Particle Measuring Systems (PMS) and Droplet Measurement Technologies (DMT). The King Probe measures cloud liquid water content (LWC) by detecting the heat released when water droplets vaporize. It operates at a constant temperature of approximately 100°C and has a data output rate of 1 to 10 Hz. The probe is commonly used in studies of cloud microphysics and aircraft icing.
The Particle Habit Imaging and Polar Scattering (PHIPS) probe is an in situ airborne cloud probe used to analyze particle shape, size, and habit. It features a high-resolution stereomicroscopic imager and a single-particle polar nephelometer. The particle imager captures images of the same cloud particle from two different angles at a resolution of 2 μm. The nephelometer measures light scattering of single particles across 20 angles from 18 to 170 degrees, with an angular resolution of 1 degree for forward scattering and 8 degrees for side and backscattering. PHIPS can measure particle sizes ranging from 50 to 700 μm for ice particles and 100 to 700 μm for water droplets. It has a field of view of approximately 3 x 2 mm and a sampling frequency of 0.7 seconds.
The 2D-Stereo Particle Probe (2D-S) is an in situ airborne optical imaging device developed by SPEC Inc. It uses two diode laser beams to create stereo images of cloud particles via linear array shadowing. These images allow for the determination of cloud particle size distribution, particle number concentration, and ice or liquid water content. 2D-S has a resolution of 10 µm and can measure hydrometeors ranging from 25 to 1280 µm.
The Airborne Vertical Atmospheric Profiling System (AVAPS) is an airborne system that uses dropsondes and Global Positioning System (GPS) receivers to gather in situ profiles of atmospheric parameters. It provides profile measurements of temperature, pressure, and humidity every 0.5 seconds, and atmospheric wind measurements every 0.25 seconds. AVAPS has a vertical resolution of approximately 10 meters and can launch dropsondes every 20 seconds. Developed by the National Center for Atmospheric Research (NCAR) for the NASA Global Hawk, it can also be deployed on other aircraft such as the DC-8 and P-3.
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Humidity
Earth Science > Atmosphere > Atmospheric Temperature
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 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.
Earth Science > Atmosphere > Atmospheric Water Vapor
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Water Vapor
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Humidity > Relative Humidity
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Humidity
The High Volume Precipitation Spectrometer (HVPS) is an in situ airborne particle imager manufactured by SPEC Inc. It uses a 128-photodiode array to capture images of precipitation particles. These images can be used to determine the particles' shape, size, and concentration. HVPS-3 has a pixel resolution of 150 μm and a maximum field of view of 1.92 cm.
The Rosemount Icing Detector (RICE) is an in-situ airborne probe developed by Rosemount Inc. It uses magnetostrictive oscillation to detect shifts in frequency caused by ice accumulation on the sensing cylinder. These frequency changes correlate with the rate of ice buildup, which helps determine liquid water content. RICE typically samples every second.
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 Turbulent Air Motion Measurement System (TAMMS) is an in situ airborne sensor used to gather aircraft navigation information. TAMMS consists of several subsystems, including pressure transducers and temperature sensors, an aircraft inertial navigation system, a central data acquisition system, and water vapor and other gas sensors. It provides measurements of aircraft position, flight level winds, temperature, pressure, and water vapor. TAMMS has a typical sampling frequency of less than 1 second and a spatial resolution of 5 meters.
Ceilometers are ground-based remote sensing sensors that measure cloud ceilings and vertical visibility. They utilize a laser or another light source to detect backscatter from clouds, precipitation, and aerosols. Ceilometers provide detailed and precise measurements under all weather conditions and are cost-effective to operate. They are commonly used in boundary layer and cloud research.
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 Two-Dimensional Video Disdrometer (2DVD) is a stationary, ground-based optical disdrometer. It features two line-scan cameras that continuously measure various precipitation properties such as droplet shape, fall velocity, and size distribution. The 2DVD accurately measures all precipitation particles with a diameter greater than 0.2 mm, making it ideal for different precipitation studies.
The Autonomous Parsivel Unit (APU) is an in situ ground-based optical disdrometer. APU measures the size and fall velocity of hydrometeors with a range of 0-25 mm in size and 0-20 m/s in fall speed. Using these measurements, the drop size distribution, type, intensity, and amount of precipitation can be determined. APU operates in the 650-780 nm wavelength range and typically samples every 10 seconds.
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 determine the column amounts of water vapor and liquid water in the atmosphere. MWR has a field of view (FOV) ranging from about 5.9 to 4.5 degrees depending on the channel and typically has a time resolution of 20 seconds for sky-view observations.
Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Water Vapor
Earth Science > Spectral/engineering > Microwave > Brightness Temperature
Earth Science > Atmosphere > Atmospheric Water Vapor
The Precipitation and Imaging Probe (PIP) is an airborne optical spectrometer developed by Droplet Measurement Technologies. It measures the size and shape of particles ranging from 100 to 6200 μm. It provides two-dimensional images with a pixel resolution of 100 μm. PIP operates at a wavelength of 660 nm and typically samples every second. It has a sample area of 260 mm by 6.2 mm and can function at airspeeds of 10 to 200 meters per second.
Pluvio is a ground-based weighing precipitation gauge manufactured by OTT HydroMet. It measures precipitation amount and rate by determining its weight using a high-capacity collection bucket. Pluvio can measure rain, snow, sleet, hail, and mixed precipitation types. It has a standard sampling interval of 1 minute and an accuracy of ± 0.05 to 0.1 mm.
The Dual-frequency Dual-polarized Doppler Radar (D3R) is a mobile Ku-/Ka-band radar that was developed for NASA’s Global Precipitation Measurement (GPM) mission Ground The Dual-frequency Dual-polarized Doppler Radar (D3R) is a mobile Ku-/Ka-band radar developed for NASA’s Global Precipitation Measurement (GPM) mission Ground Validation (GV) program. D3R measures radar backscatter to provide reflectivity, Doppler velocity, differential reflectivity, correlation coefficient, and other radar observations. These measurements help derive droplet size distribution and identify hydrometer types. D3R has a beam width of approximately 0.9 degrees, a maximum range of 30 km, and a gate spacing of 150 m. It operates at wavelengths similar to the Dual-frequency Precipitation Radar (DPR) on the GPM Core satellite and can be used to validate DPR observations.
Digital cameras are used to provide imagery for research applications. Cameras are used on aircraft to collect aerial imagery for mapping and surveying, environmental monitoring, cloud observations, agriculture, geological studies, and other Earth science applications. They are also used at field sites to capture visual observations to monitor changes in land cover, vegetation, clouds, air quality, glaciers, and other phenomena.
The Micro Rain Radar (MRR) is a ground-based, vertically oriented, continuous wave K-band (24.23 GHz) radar that measures various parameters of precipitation, such as liquid water content and rain rate, from near ground level to the lower troposphere. The backscatter captured by the MRR’s antenna can determine precipitation size distributions ranging from 0.25 mm to 4.53 mm and can also calculate the frequency shift of falling precipitation to determine its velocity. Additional uses of the MRR include identifying bright bands, nowcasting precipitation, and tracking chemical transport during precipitation events. It has a range resolution of 10 to 200 meters and a sampling time of 10 seconds.
The NASA S-band Dual Polarimetric Radar (NPOL) is a portable, ground-based scanning dual-polarimetric Doppler radar. As an active remote sensor, NPOL detects reflected electromagnetic waves to determine radar reflectivity, Doppler velocity, rainfall rate, particle size distribution, water content, and precipitation type. Normally, NPOL has a beamwidth of 0.95°, a gate spacing of 0.15 km, and a maximum range of 150 km. It is operationally comparable to Doppler radars used by the U.S. National Weather Service’s Next Generation Weather Radar (NEXRAD) network, but NPOL has the benefit of being fully deployable.
The Ka-band Scanning Polarimetric Radar (KASPR) is a ground-based polarimetric Doppler radar at the Stony Brook University (SBU) Radar Observatory. It is a 35.29 GHz radar that measures reflectivity, Doppler velocity, and other polarimetric radar observations to characterize clouds and precipitation. KASPR has a beamwidth of 0.32 degrees and a range resolution of 15 to 200 meters.
