GaoFen-4 (GF-4) infrared spectrum (IRS) camera has a special spectral band located in the mid-wave infrared spectrum with the wavelength ranging from 3.50 to 4.10 μm. It is very important for forest fire-detection and other quantitative remote sensing applications at a high spatial resolution of 400 m. Due to the similarity of the spectral characteristics, the thermal emissive band 20 (3.660-3.840 μm) and 22 (3.929-3.989 μm) of medium resolution imaging spectrometer (MODIS) are taken as the reference bands for the radiometric cross-calibration of the GF-4/IRS camera. The time difference between selected GF-4/IRS and MODIS images at the Qinghai Lake and Se lincuo Lake test sites is less than one hour. After spatial matching, single-band and dual-band spectral matching methods are proposed in this article. Then, the DN value of GF-4 image is linearly fitted to the radiance of the corresponding MODIS image to obtain the radiometric calibration coefficients of GF-4/IRS camera. The validation results show that the cross-calibration coefficients calculated by integrating the measurement of two MODIS bands with the mean value spectral matching approach has the highest radiometric calibration consistency with the official calibration coefficients.

中文翻译：

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基于 MODIS 测量的 GF-4/IRS 辐射交叉校准


高芬-4（GF-4）红外光谱（IRS）相机具有位于中波红外光谱中的特殊光谱带，波长范围为3.50至4.10μm。它对于400 m高空间分辨率的森林火灾探测和其他定量遥感应用非常重要。由于光谱特性相似，选取中分辨率成像光谱仪（MODIS）的热发射波段20（3.660~3.840 μm）和22（3.929~3.989 μm）作为参考波段进行辐射交叉标定。 GF-4/IRS 相机。青海湖和色林措湖试验场所选GF-4/IRS与MODIS影像的时间差小于1小时。在空间匹配之后，本文提出了单波段和双波段光谱匹配方法。然后将GF-4图像的DN值与相应MODIS图像的辐射亮度进行线性拟合，得到GF-4/IRS相机的辐射定标系数。验证结果表明，采用均值光谱匹配方法综合两个MODIS波段的测量结果计算出的交叉定标系数与官方定标系数具有最高的辐射定标一致性。