A NOVEL MODEL FOR ORIENTATION OF LINEAR OPTICAL SATELLITE IMAGES BASED IN THE ADAPTATION OF THE ORBIT-ATTITUDE MODEL

Abstract In this paper a novel model to orient a pushbroom linear optical satellite image is proposed. This one is based in the adaptation of the Orbit-Attitude model for use of the Modified UCL Kepler platform model. It has only the components of satellite position and velocity as unknowns. This implies not only the reduction of unknowns but also the elimination of initial adjustments of the orbit to estimate the polynomial parameters. In order to validate the model, four experiments were conducted using one HRC-CBERS 2B image. Two distributions of ground controls points (GCPs) were tested, 70 and 35 GCPs. A quantity of 43 check points (CPs) was used to analyze the planimetric accuracies of the orientations. For comparisons purpose the image was also oriented with platform model using 2nd order polynomial. The results showed that the planimetric accuracy difference in the use of the two models is 4 and 6 centimeters in the two mentioned configurations of GCPs, respectively. However, the main advantage of applying the proposed model is the direct use of ephemeris without the necessity of interpolations and pre-adjustments, which makes the orientation process simpler.

摘要 本文提出一种用于推扫式线阵光学卫星影像（pushbroom linear optical satellite image）定向的新型模型。该模型基于轨道-姿态模型（Orbit-Attitude model）的适配改造，以适配改进型UCL开普勒平台模型（Modified UCL Kepler platform model）的使用需求，仅将卫星位置与速度分量设为未知量。这不仅缩减了未知量的数量，同时无需预先开展轨道调整以估计多项式参数。为验证该模型的有效性，研究团队使用1幅HRC-CBERS 2B影像开展了4组实验。本次测试了两种地面控制点（ground controls points，GCPs）布设方案，分别包含70个与35个地面控制点，并引入43个检查点（check points，CPs）以评估该定向方法的平面定位精度。为开展对照实验，研究团队同时采用二阶多项式平台模型对该影像进行定向处理。实验结果表明，在上述两种地面控制点布设方案下，两种模型的平面定位精度差异分别为4厘米与6厘米。然而，所提模型的核心优势在于可直接使用星历（ephemeris）数据，无需进行插值与预调整操作，从而简化了定向流程。