Research In The Calibration And Test System Of Imaging Spectrometer Based On LCTF

The figure and spectral information of the targets with interest can be both obtainedthrough imaging spectrometers, which has been used widely in the field of space remotesensing, biomedical science and precision agriculture, etc., showing good applicationprospects. A kind of imaging spectrometer based on LCTF (liquid crystal tunable filter) hasbeen presented in this thesis, the calibration and test system for the imaging spectrometer isfocused.Some basic theories of LCTF have been introduced at the beginning of this thesis. Thetransmittance characteristics have been simulated numerically, the working principle and thedesign scheme have been sketched. The calibration project has been designed and analyzedcarefully, mathematic model is built for the calibration system and the method of recoveringthe reflectance spectrum is put forward. According the calibration scheme we designed, wetest the stability and uniformity of the light source and revised the un-uniformity of theimage’s gray value distribution. The experiments of imaging spectrometer’s spectrumcalibration and radiometric calibration have been implemented and the results of thoseexperiments have been discussed.Besides, we capture the whole spectrum range’s gray-scale images of the leaf in thewinter with imaging spectrometer, after that we finish the experiment of color synthesis andtransform with ENVI software, then the reflectance spectrum curve of the leaf is obtainedwith standard white board. The results indicate that the calibrated imaging spectrometer canwork stably. We can acquire the clear image and get the accurate spectrum information of theimaging targets at the same time.