光栅成像光谱仪图像畸变校准方法研究

成像光谱仪是一种"图谱合一"的光学遥感仪器。光栅型成像光谱仪由于原理简单,性能稳定,技术发展成熟等优点得到了广泛的应用。光栅成像光谱仪中不同采样步长的选择及不合理的拼接方法会导致目标图像(分划板图像)的畸变,会使原来分划板图像中的正方形发生不同程度拉伸或者压缩成为矩形。现采用He-Ne激光器确定成像光谱仪的通带宽度,并利用低压汞灯进行波长定标,确定特定波长所对应的像元数,通过基于区域和小波变换的拼接方法完成目标图像,从而对目标图像的畸变进行校正。实验证明,可以使畸变量相比原始块匹配拼接方法减小一个数量级。

Image distortion calibration of imaging spectrometer with grating dispersion

Imaging spectrometer is a kind of optical remote sensing instruments which combines image with spectrum. Grating based imaging spectrometer has a wide range of applications because of its concise principle, stable performance and technology maturity. Grating imaging spectrometer in different sampling frequency choices and unreasonable splicing method will lead to target image (retile image) distortion, making the original rectangular square retile image stretch or compress in varying degrees. The He Ne laser measure pass band width of imaging spectrometer is used and low pressure mercury lamp adopted for wavelength calibration, which determines the specific wavelength corresponding to the pixel number. Then, with the method based on region and wavelet transform, the target image is achieved, which then can be used to correct the target image distortion. The experiment shows that the distortion with this method decreases considerably compared with the result of the original splicing method.