天绘一号03星无控定位精度改进策略

“全球连续覆盖模式”传输型摄影测量卫星系动态摄影,无控定位模式下难以达到框幅式像片定位水平.本文在天绘一号已有研究基础上,深化03星摄影测量无控定位精度改进模式的探讨研究.在相机参数在轨标定中增加对相机内方位元素的附加改正,解决相机结构宽高比(卫星条带摄影覆盖宽度与卫星轨道高度的比值)太小对主距标定结果的影响,进而削弱系统误差,提高卫星影像的平面定位精度.通过境外地区检测,无控定位精度达到高程2.4m (RMS),平面3.7m (RMS).检测结果表明,只依靠星上GNSS接收机、星敏感器,利用相机参数在境内标定结果,“全球连续覆盖模式”单航线卫星影像无控定位结果达到理论设计指标.

Improvement strategy for location accuracy without ground control points of 3rd satellite of TH-1

The transmission photogrammetric satellite with global coverage on a continuous basis belongs to dynamic photography, and the location without ground control points (GCPs) can-not reach to the level of the frame imagery. In this paper, the location without GCPs is researched in-depth about 3th satellite, based on the existing research results of TH-1. In order to counteract the negative effect of small width-to-height ratio (ratio of satellite strip photographic coverage width to satellite orbital height), the additional corrections of interior orientation elements were performed during the on-orbit calibration. As a result, the systematic errors were reduced while the horizontal location accuracy was improved, and the location accuracy without GCPs have achieved to 3.7 m (horizontal accuracy) and 2.4 m (vertical elevation accuracy) using foreign testing field. The location without GCPs of a single strip satellite imagery with global coverage on a continuous basis can be improved to the theoretical level by using its GNSS receiver, star tracker and domestic calibration results of camera parameters.