Advanced Instrumentation for Full Spectral Imaging
This page summarizes some advanced concepts that could be employed in instruments for Full Spectral Imaging
[Note: Simply put, the "bottom line" for instrument performance is the number of photons collected. Signal-to-noise, spatial resolution and coverage, and spectral resolution are all dependent on the number of photons. some of the techniques for capturing and processing these photons are described below.]
Fore Optics
* Pushbroom system (no scan mirror)
* All reflective, low stray light, wide field-of-view
* Earth curvature ("bow tie effect") correction
* Forward motion compensation for elimination of pixel smear
* Multiple or Multiplexed (spatially co-aligned) focal planes to feed multiple spectrometers
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Spectrometers
* Replica optics for identical multiple spectrometers [dispersing system changed for band selection]
* Multiple spectrometers for VIS-NIR, SWIR, and IR coverage
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Detector
* Self shuttering ("instantaneous" readout)
* Alternative technologies for higher dynamic range and better readout options
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Electronics
* Non-linear (square root) detector readout to minimize bits per band
* Real-time conversion from raw band data to full spectral data
* Real-time "spectro-spatial data" compression"
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Image Processing
* Empirical derivation of atmospheric characteristics from multi-target full-spectral data
* Empirical derivation of instrument calibration
* Empirical retrieval of reflectance at the target
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Spacecraft
* Yaw and roll control system for compensation for Earth rotation
* Direct broadcast to distributed and networked receiving stations
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This page was last modified on Wednesday, October 28, 2009