Position precision evaluation of ZY-3 satellite image in the coastal zone of China

Abstract

With China's coastal zone as the research area,6 ZY- 3 sensor corrected products were chosen for evaluation,which covered Qingdao of Shandong,Yancheng of Jiangsu and Wenzhou of Zhejiang from north to south. The authors used high accuracy GPS points to evaluate the autonomous positioning precision in comparison with SPOT5 images. Then DOMs were generated with high accuracy GPS points as ground control points( GCPs)and national 1∶ 50 000 DEM products,and the influences of the quantity and distribution of GCPs were analyzed.The results show that the average autonomous positioning precision of ZY- 3 panchromatic image and that of multispectral image are 19. 6 m and 23. 0 m,respectively. The autonomous positioning precisions of ZY- 3panchromatic image and multispectral image are better than the precision of SPOT5 images. With 1 GCP at the four corners,the positioning precision of DOM is less than 2 pixels. With 4 GCPs,the positioning precision of DOM is about 1 pixel. With 2 landside corner GCPs,the positioning precision of DOM is less than 3 m. With 3 landside GCPs,the positioning precision of DOM is lower than that of 2 landside GCPs,especially at the seaside. The results show that,with a few GCPs,ZY- 3 DOM can reach high accuracy and satisfy the need of coastal zone remote sensing survey.