Many climate and surface energy balance studies involve monitoring the direct, diffuse and total components of solar spectral irradiance as they relate to the earth’s atmosphere and surface. In addition these irradiance measurements, ecosystem modeling studies often require the measurement of photosynthetic photon flux density (PPFD), photosynthetically active radiation (PAR), as well as canopy reflectance and radiance.

In order to improve these climate and ecosystem models, it is essential to measure the variation of these properties across and within a wide variety of ecological sites. In some cases these studies correlate these optical measurements with physical surface properties such as temperature, gas exchange, and, in the case of agricultural studies crop output.
Portable visible and near infrared spectroscopic technology is useful across a broad base of applications in atmospheric research. Spectroscopy is used for ground truth and airborne measurements, and calibration to satellite sensors both pre-flight and post-launch through vicarious field calibrations.

ASD’s ultra-portable FieldSpec® systems allow you to collect the measurements you need easily and quickly. ASD also offers accessories for all of your needs, including solar tracking stages and cosine receptors for direct irradiance measurements.

Select any of the links below to see work by other researchers using ASD instruments for atmospheric modeling and research.

Practical Atmospheric Correction Algorithms for a Multispectral Sensor from the Visible Through the Thermal Spectral Regions

The MODIS/ASTER Airborne Simulator (MASTER) — A New Instrument for Earth Science Studies

Post-Launch Validation of Multispectral Thermal Imager (MTI) Data and Algorithms

NREL Optical Metrology Laboratory

Planned Participants & Measurements for the 1999 Cruise of the NOAA R/V, Ronald Brown

Radiometer Measurements for Estimation of TOA Radiances

Southern Africa Validation of EOS (SAVE) Status Report Period of Report: 6 June 2000 -- 28 Sept. 2001

For more information about the ASD FieldSpec® spectroradiometers used in atmospheric research for direct, diffuse, irradiance, and radiance measurements select the links below.