Time Registration Of Imaging Spectrometer With Grating Dispersion

Imaging spectrometer is a kind of optical remote sensing instruments which combins image with spectrum. Grating-based imaging spectrometer has a wide range of applications because of concise principle, stable performance, and mature of the technology.Grating imaging spectrometer in different sampling frequency choice and not reasonable splicing method leads to the target image (retile image)distortion, and make the original rectangular square retile image stretching or compression occurs to varying degrees.Now the usage of the He-Ne laser measure pass band width of imaging spectrometer and usage of low pressure mercury lamp for wavelength calibration, determine the specific wavelength corresponding to the pixel number. Experiments show that, this method can make the image distortion compared to the original block matching image mosaic method decreases an order of magnitude, to four decimal orders of magnitude accuracy requirements. The specific research contents are as follows:First, identifying discrete points of the range of the amount of distortion with the step change through experimental. To identify the point through MATLAB fitting a curve, we can find the variables and objectives of the mathematical relationship of the amount of image distortion. Thus getting the image of a step that the sampling frequency of the small amount of distortion;Second, in order to obtain the amount of distortion of the ideal requirements, my paper are aimed at the target image stitching method based on mutual information and wavelet transform, Compared to the original block-matching the splicing method reduces an order of magnitude. Thus completing the time of imaging spectrometer alignment;Again, analysis of the impact of the size of the photosensitive element on the sampled signal, convolution and analyze the principle of the spectral distortion, eliminate spectral distortion calibration method, restore the characteristic lines and the impact brought about by the convolution process, imaging Spectrometer space to complete the registration;Finally, verify the registration of this system in line with project needs that met the design requirements.