国产机载大视场三线阵CCD相机GNSS偏心矢量和IMU视轴偏心角标定技术

针对国内首台自主研制的机载三线阵CCD相机（以下简称GFXJ），开展了国产GFXJ的GNSS偏心矢量和IMU视轴偏心角标定技术研究工作。首先介绍了GFXJ相机的成像特点，然后分析建立了GFXJ的GNSS偏心矢量标定模型和IMU视轴偏心角标定模型，并提出了GNSS偏心矢量和视轴偏心角循环两步法标定方案，最后在国家嵩山遥感综合实验场获得了多次飞行试验数据。通过进行区域网平差和标定处理，验证了本文建立的GNSS偏心矢量标定模型和IMU视轴偏心角标定模型的正确性和有效性，证实了本文提出的循环两步法标定方案可靠、可行，可显著提升GFXJ的几何定位精度。利用GNSS偏心矢量和IMU视轴偏心角标定值，大幅提高了GFXJ相机的无控定位精度。辅以少量控制点进行区域网平差，GFXJ影像平面定位精度可满足1：1000地形图测图的空中三角测量精度要求，高程精度距离指标要求略有差距。目前该款相机仍在校飞阶段，定型后几何性能有望进一步提高。同时，本文建立的GNSS偏心矢量标定模型和IMU视轴偏心角标定模型及提出的循环两步法标定方案，可为其他机载线阵CCD相机的标定处理提供借鉴。

Investigation on GNSS Lever Arms and IMU Boresight Misalignment Calibration of Domestic Airborne Wide-field Three CCD Camera

Focusing on the first domestic developed airborne three line CCD camera (GFXJ), it is carried out that the innovative investigation work on GNSS lever arms and IMU boresight misalignment calibration of GFXJ camera. Firstly, a brief introduction is given on the imaging properties of GFXJ camera. Then, the GNSS level arms calibration model and IMU boresight misalignment calibration model are built for GFXJ camera after detailed investigation. Meanwhile, the iterative two-step calibration scheme is put forward for the GNSS level arms and IMU boresight misalignment calibration of GFXJ camera. Finally, multiple sets of flight data are captured under the support of the national Songshan remote sensing comprehensive testfield. Through the block adjustment and calibration experiments of these sets of imaging data, it verifies the correctness and the efficiency of proposed GNSS lever arms calibration model and IMU boresight misalignment calibration model, and also demonstrates the reliability and practicability of the iterative two-step calibration scheme for GFXJ camera. The proposed calibration scheme can significantly enhance the geometric positioning accuracy of GFXJ camera. Using the GNSS level arms and the IMU boresight misalignment calibration values, the uncontrolled positioning accuracy of GFXJ camera can be significantly improved. Aided with several control points for re-block adjustment, the planar positioning accuracy of GFXJ camera can fulfill the accuracy requirements of 1:1000 scale mapping, but there still exists a little gap between its height positioning accuracy and the 1:1000 scale mapping requirements. The camera is still in the calibration flight stage, its geometric performance can be further improved after product approval. Moreover, the GNSS lever arms calibration model, the IMU boresight misalignment calibration model, and the iterative two-step calibration scheme put forward in the paper can be applied to calibration work for other airborne CCD cameras.