Calibration

Calibration Capabilities

All remote sensing sensors receive electromagnetic radiation. The sensor then converts the radiation into an electronic signal. However, an electronic signal is meaningless unless it is related to a physical unit. Simply speaking, calibration of a remote sensing sensor is the procedure to establish the conversion parameter that translates output of the sensor to a measurable physical unit.

For example, the output reading of a spectroradiometer has the units of radiance at a specifically measured wavelength. The spectroradiometer must be properly calibrated in radiance, irradiance, and wavelength .

In the case of an airborne imaging spectrometer, the sensor measures not only the radiance but also the spatial aspects of the image. Calibration requires characterization of the spatial resolving and positioning capability of the instrument. Other calibrations may be required due to specific optical system used. (e.g. whisk broom scanning, push broom scanning, single-facet scanning, or multi-facet scanning optics, etc.)

Spectra Vista Corporation maintains a fully equipped optical laboratory for complete calibration and characterization of all Spectra Vista or GER produced sensors.

The following is a list of calibrations performed on our products.

Field Portable Spectroradiometers

1. Wavelength calibrations: All field spectrometers are calibrated to their published specification. Equipment most often used in this calibration include: fully automated monochrometer, spectral line source (e.g. Argon, Mercury, Krypton, etc.), narrow band filters and other known band targets.
Proprietary software is used to generate calibration parameters from all calibration measurements.

2. Radiometric calibrations: All field portable spectrometers are calibrated by NIST traceable, automated integrating sphere calibration standard (Optronic Laboratories, Inc., OL Series 462).

3. Field of View calibrations: The optical field of view for a field portable spectrometer determines what is being measured. All field spectrometers are calibrated to give a clearly defined field of view.

For additional information on equipment calibration capabilities, contact us