Field measurements with an ASD.
In order to make accurate measurements of surface reflectance properties of various vicarious calibration target sites, the Remote Sensing group makes use of three Analytical Spectral Devices (ASD) FieldSpec spectral radiometers. The ASD radiometers are portable array-based spectrometers consisting of a spectrometer unit, computer interface, and 2-m long fiber optic probe inserted into a foreoptic (generally carried on a boom to insure that data collected are not shadowed by the user). Two of these radiometers are Full Range (FR) devices employing a silicon photodiode array and two fast scanning thermoelectrically cooled spectrometers capable of data collection from 350-2500 nm with a spectral resolution between 3-20 nm (depending on the detector). The third ASD instrument is a UV/VNIR-only system with a single silicon detector array, capable of data collection from 350-1050 nm. These systems may be operated in the field with 1°, 5°, or 8° full-field-of-view (FFOV) foreoptics, depending on the application.
Data collected with these instruments can be viewed in real time through the portable computer interface, carried on top of the spectrometer itself. Visit the ASD homepage for more information on these devices.