The NASA Airborne Microwave Observatory of Subcanopy and Subsurface (AirMOSS) campaign focused on observing root zone soil moisture (RZSM) and net ecosystem exchange (NEE) of carbon dioxide across different North American biomes over multiple seasons. AirMOSS completed 34 deployments from 2012 to 2015, covering parts of Canada, the US, and Costa Rica. The airborne observations included P-band synthetic aperture radar (SAR) measurements as well as carbon and other gas concentrations. AirMOSS was part of the NASA Earth Venture Suborbital 1 (EVS-1) program.
The AirMOSS P-band Radar is an airborne synthetic aperture radar (SAR) developed by the Jet Propulsion Laboratory (JPL). It was based on the Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) L-band radar and has been part of the UAVSAR instrument suite since the AirMOSS investigation was completed in 2015. AirMOSS collects radar data to measure root-zone soil moisture, permafrost, underground structures, and subsurface changes. It operates over the 280-440 MHz frequency range and can detect up to 1.2 m below the land surface. AirMOSS has a slant range resolution of 7 m and a range swath width of 7 km at a nominal altitude of 12,500 m.
The Best Air Turbulence (BAT) probe is an in-situ airborne wind sensor developed by NOAA. It is mounted on the front of an aircraft to provide high-frequency wind measurements. The BAT probe measures wind speed and direction relative to the aircraft, while a GPS and accelerometers measure the aircraft’s velocity relative to the Earth. These data are combined to determine atmospheric pressure, temperature, and wind at a sampling rate of 10 Hz. The BAT probe is usually mounted on aircraft but can also be deployed on ships and vehicles.
The Picarro gas concentration analyzer is an in situ airborne or ground-based sensor manufactured by Picarro, Inc. It uses Wavelength-Scanned Cavity Ring Spectroscopy (WS-CRDS) to measure trace gases such as carbon dioxide, carbon monoxide, methane, and water vapor. For carbon dioxide measurements, the laser within Picarro operates at 1603 nm wavelength, while 1651 nm wavelength is used for methane and water vapor measurements. Picarro has a typical sampling time of 2.5 seconds. Depending on the model, Picarro can also provide measurements of carbon isotopes for gas concentrations.
FLUXNET is a global network of eddy covariance flux towers. Each tower is equipped with gas sensors to continuously measure the fluxes of trace gases such as carbon dioxide, methane, and water vapor between the land surface and the atmosphere. These towers are also equipped with various meteorological sensors to measure air temperature, precipitation, winds, radiation, and soil temperature. Currently, FLUXNET has over 250 flux tower sites across the globe in various vegetation types such as tundra, tropical, forest, and grasslands.
Earth Science > Land Surface > Soils > Soil Temperature
Rain gauges are ground-based instruments that measure liquid precipitation amounts directly over a specified period. Different rain gauges, such as tipping buckets and weighing gauges, collect and record data in various ways. Because of their small size and easy setup, rain gauges can be placed in different locations and are often used alongside other precipitation instruments like disdrometers to gather more details, such as precipitation rate and size distribution.
Earth Science > Spectral/engineering > Infrared Wavelengths > Brightness Temperature
Soil moisture probes are in situ ground-based sensors that measure soil water content. The most common type of soil moisture probes used for scientific research use dielectric permittivity techniques, such as capacitance 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 Best Air Turbulence (BAT) probe is an in-situ airborne wind sensor developed by NOAA. It is mounted on the front of an aircraft to provide high-frequency wind measurements. The BAT probe measures wind speed and direction relative to the aircraft, while a GPS and accelerometers measure the aircraft’s velocity relative to the Earth. These data are combined to determine atmospheric pressure, temperature, and wind at a sampling rate of 10 Hz. The BAT probe is usually mounted on aircraft but can also be deployed on ships and vehicles.
