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为了研究温度对机载成像光谱仪谱线漂移的影响,分析了机载环境下仪器温度载荷的特点、作用机理和表现形式,研究了光谱仪的谱线漂移特性。根据机载环境下温度载荷特点,利用有限元法,结合最小二乘法和坐标转换法,计算了光学系统各镜面在温度载荷作用下面形变化和刚体位移。对变形后的光学系统进行了光线追迹,研究了其谱线漂移特性。通过热光学实验和飞行成像期间光谱定标实验验证了理论分析。热光学实验表明,在±10℃温度变化范围内,谱线在光谱方向仅发生整体平移,没有拉伸或压缩效应。在飞行期间的定标实验中,其平均谱线偏移量为0.248 nm,满足定标精度的1/3(定标精度为1 nm)要求。后续成像不需要再进行光谱定标或光谱修正。
In order to study the influence of temperature on the spectral drift of airborne imaging spectrometer, the characteristics, mechanism and manifestation of temperature load on airborne environment were analyzed, and the spectral line drift characteristics of the spectrometer were studied. According to the temperature load characteristics under airborne environment, the shape change and rigid body displacement of each mirror of the optical system under temperature load were calculated by using the finite element method and the least square method and the coordinate transformation method. Ray tracing of the deformed optical system was carried out and its spectral line drift characteristics were studied. The theoretical analysis is validated by experiments of thermo-optical experiments and spectral calibration during flight imaging. Thermal experiments show that within ± 10 ℃ temperature range, the spectral line only in the spectral direction of the overall translation, there is no stretching or compression effect. In the calibration experiment during flight, the average spectral line offset is 0.248 nm, which meets 1/3 of the calibration accuracy (calibration accuracy is 1 nm). Subsequent imaging does not require further spectral calibration or spectral correction.