On-Orbit Spectral Calibration and Validation of GF5-02 Advanced Hyperspectral Imager

On September 7, 2021, the GaoFen5-02 (GF5-02) Satellite, the new generation of Chinese hyperspectral remote sensing satellite was successfully launched. GF5-02, the successor to the GF5 satellite, was equipped with six advanced hyperspectral payloads. One of the most important payloads onboard the GF5-02 satellite, the advanced hyperspectral imager (AHSI) has a spatial resolution of 30 m, 330 bands in a spectral range of 380–2500 nm. The spectral resolution of the visible and near infrared (VNIR) and short-wave infrared (SWIR) bands are better than 5 and 10 nm, respectively. To analyze the spectral performance of the GF5-02 AHSI, an on-orbit spectral calibration method that utilizes atmospheric limb observations with an on-board calibration system was proposed in this letter. The on-orbit spectral calibration results were validated by atmospheric absorption features with synchronous measurements of surface reflectance and atmospheric parameters. For the GF5-02 AHSI, the shifts in the central wavelength of the VNIR band is 0.117nm, while the shifts in the full width at half maximum (FWHM) is 0.02 nm. In the SWIR band, these values are 0.25 nm for the central wavelength and 0.04 nm for the FWHM. The results demonstrate that the applied method is effective for on-orbit spectral calibration for GF5-02 AHSI.