多航帶推掃式衛星方位平差及影像正射化

Block Adjustment and Orthorectification for Multi-Orbit Satellite Images

劉建良(Chien-Liang Liu) ； 陳良健(Liang-Chien Chen)

《航測及遙測學刊》 11卷2期 (2006/06) Pp. 213-236

https://doi.org/10.6574/JPRS.2006.11(2).8

摘要

對於大範圍土地利用監測應用，單張衛星影像可能無法涵蓋目標區域。以多軌道正射影像，經鑲嵌可得到大範圍正射影像。若不同軌道衛星影像單獨進行方位重建，可能造成相同地面點在兩張正射影像上不重合，使鑲嵌後之正射影像在接縫處有錯開的現象，欲減少此現象，在軌道幾何校正時區域平差為較佳的方式。本研究將提出一個軌道區域平差模式，其主要工作包括(1)建立載體參數修正模式、(2)計算航帶連結點修正向量、(3)以最小二乘過濾法進行衛星軌道精密修正及(4)影像正射化，最終進行正射影像鑲嵌。
實驗結果顯示，加入航帶連結點進行軌道區域平差後，軌道間相對誤差小於6公尺，且減少鑲嵌影像接縫處錯開現象。

關鍵字

區域平差 ； 軌道修正 ； 最小二乘過濾模式 ； 航帶連結點 ； 影像正射化

並列摘要

In various applications, areas of interest sometimes cover two or more satellite images, thus mosaicking for those images becomes important. Scene-based orbit adjustment could yield geometric discrepancies that could cause image discontinuity along the seam line during mosaicking. Thus, block adjustment is preferable. The objective of this investigation is to establish a simple yet effective block adjustment procedure for multi-orbit satellite images. The major works of the proposed scheme are: (1) adjustment of satellite's orbit accurately, (2) calculation of the error vectors for each tie point using digital terrain model and ray tracing technique, (3) refining the orbit using the Least Squares Filtering technique and (4) generation of the orthophotos.
Test images are from SPOT 5 satellite. Experimental results indicate that, the relative accuracy between orthoimages is about 6 meter. It is also demonstrated that the mosaicked image is better seamed when tie points are employed in the adjustment.

並列關鍵字

Block Adjustment ； Least Squares Filtering ； Tie Points ； Orthoimage