星载紫外临边探测仪切点几何定位与切高订正OA

Accurate assessment and correction of on-orbit pointing errors and tangent height deviations of limb sounders are essential for achieving high vertical accuracy in global trace retrievals.For the newly launched Ozone Monitoring Suite-Limb(OMS-L)onboard Fengyun-3F,the geometric pointing model of the scanning mirror was established based on the precisely measured instrument coordinate system.The tangent height calculation model was constructed using an equidistant virtual ellipsoid.Eight configuration parameter modes were designed to analyze the influence of the earth model,orbital and attitude informa-tion,installation parameters,and their combined effects on the theoretically designed tangent heights.During on-orbit testing,the systematic tangent height deviation was identified by knee-point method.To correct this deviation,the pitch installation parameters were adjusted,and the pointing stability of the in-strument was statistically analyzed over a period of 12 months.The results show that the tangent height correction accuracy is better than 0.4 km,and the annual inter-annual variation of the instrument vertical(along-track)pointing is less than 0.01°.For cross-track pointing accuracy,image matching was per-formed using reference images acquired from the same platform and spectral band of the earth observation instrument.The results show that the cross-track pointing deviation of OMS-L reach 0.1°.The on-orbit pointing accuracy of OMS-L met the requirements for trace gas inversion and retrieval.