A new solid-state source has been developed to emulate the solar spectrum for absolute radiometric calibration of advanced multispectral and hyperspectral imagers. The source is used in conjunction with quartz tungsten-halogen lamps (QTH) on an integrating sphere to provide a solar spectrum matching the AM1.5 spectrum from 385nm to 2500nm. The performance criteria required a source with “smooth” spectral shape to minimize spectral mismatch errors in the calibration as well as minimizing the differences between power in different bands to allow sensor arrays to be calibrated with equivalent integration times. A method has also been developed to quantify the “smoothness” of the calibration spectra and the expected error in the resulting spectral response calibration for measurement of various source spectra.
Labsphere, Inc. in conjunction with NASA GSFC and Genesis Engineering Solutions Inc., has developed an innovative, vacuum compatible, calibration spectro-radiometric illumination source with a highly uniform large-area rectangular flat panel active area. This device features a uniquely shaped diffuse integration geometry to achieve high uniformity over a large active output area while maintaining a smaller and more robust overall form-factor when compared to previous designs or integrating spheres. A new liquid-cooled hybrid quartz-tungsten (QT) and light emitting diode (LED) source module has been engineered to provide direct-in-vacuum reference illumination over the full dynamic range and spectrum of the VIIRS instrument’s optical bands during pre-launch testing. The first unit has been demonstrated to meet its requirements using ambient technology and a fully-vacuum-compatible second unit is planned to allow testing in thermal vacuum (TVAC) campaigns. This technology is flexible and capable of meeting the needs of many other instruments/missions requiring this type of test/calibration capability.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.