Hyperspectral Sensor Calibration Lab The Calibration Home Base

1. 4 2 1 5 3 Schema of folding mirror and linear stage Hyperspectral Sensor Calibration Lab The Calibration Home Base Karim Lenhard, Jochen Fries, Birgit Suhr and Peter Gege DLR Oberpfaffenhofen operates a calibration facility (Calibration Home Base, CHB) for airborne optical sensors and hyperspectral field instruments in a wide spectral range. It was designed with aircraft-based sensors in mind and can therefore accommodate large and heavy sensors. The CHB is specifically devised to provide equipment for radiometric, geometric and spectral measurements and can also be used for the measurement of polarisation effects, stray light or electronic properties. The CHB was partially funded by ESA to establish a calibration facility for the airborne imaging spectrometer APEX. • Radiometric Calibration • Integrating sphere #1: Small aperture, calibrated against PTB standard • Used for absolute calibration • Integrating sphere #2: Wide aperture, 18 different lamps • Used for relative calibration at different intensities • Geometric Calibration • Narrow slit imaged via a collimator • Enables measurement of: • Across and along track Line-Spread-Function (LSF) • Pixel coordinates • Instantaneous Field Of View, Field Of View Facility with a hyperspectral sensor mounted • Integrating sphere #1 • Integrating sphere #2 • Hyperspectral Sensor ROSIS with alignment interface • Folding Mirror • Monochromator Across track measurements performed by imaging a narrow slit onto a sensor, yielding the LSF • Folding Mirror Concept • Sensor is mounted in regular flight position • Large and heavy sensors (<350 kg) can be accommodated • Geometric and spectral calibration can be performed without realigning the sensor • Automation of extensive calibration procedures is possible via lab software • Spectral Calibration • Monochromator wavelength range: 350 nm – 14 µm • Enables measurement of: • Center wavelengths • Bandwidths, oversampling • Smile and frown Remote Sensing Technology Institute Bilder mit max. 200 dpi bezogen auf die gewünschte Zielgröße Response curves of five adjacent channels, showing center wavelength, bandwidth and oversampling Remote Sensing Technology Institute DLR Oberpfaffenhofen D-82234 Wessling Internet: www.dlr.de/caf