In conventional aerial photogrammetry, high precision photogrammetric point determination is always carried out by aerotriangulation using a great deal of ground control points around the perimeter and in the center of a block area because the exterior orientation parameters of aerial photographs are unknown. A technological revolution in photogrammetry has taken place since Navstar Global Positioning System (GPS) was applied to determine the 3D coordinates of exposure station positions during the photo flight missions. GPS-supported aerotriangulation is conducted by a combined bundle adjustment wth GPS navigation data, which replaces the essential ground control points with GPS-determined camera positions. The simulation experiments of GPS-supported aerotriangulation can date back at least to 1986. Recent investigations show this method is now practical. We have been engaged in theoretical studies, software development, and related to experiments and production on the field since 1990. So far, most-abundant research achievements are obtained in terms of the theory and application. In this paper, we first derive the mathematical model of combined bundle adjustment with GPS navigation data from the geometry between camera and airbrone GPS antenna, and then describes briefly a software package WuCAPS (Wuhan Combined Adjustment Program System) developed by the author, which serves the purpose of combined bundle adjustment for photogrammetric and non-photogrammetric observations. At the end of the present work,a set of actual aerial photographs, at an image scale of 1:34,000, with airborne GPS data taken fromTianjing site in China were processed by our WuCAPS. The empirical results have verified that theaccuracy of the combined bundle adjustment with 4 XYZ ground control points around the corners of block area is very closed to that of the conventional bundle adjustment with 3 additional parameters, which leads to an 88% reduction in field survey and 75% saving in production cost, and can meet the specification of topographic mapping at small or medium scale by GPS-supported aerotriangulation without ground control. This shows the ample applicability and the economic benefit of kinematic GPS relative positioning in high accurate photogrammetric point determination.

对某城区一对1：8000航摄立体数字影像利用Intergraph数字摄影测量工作站上的立体量测软件IS-DM进行手工量测，然后通过用自行开发的GPS辅助光束法区域网平差软件WuCAPSGPS的单模型光束法平差精确测定了18个加密点的位置。经过对数字影像采用1到100不同质量因子的JPEG压缩，获得一组质量各异的压缩影像，从分析重建影像点定位结果的变化入手，探讨了JPEG压缩对摄影测量点定位精度的影响。试验表明：失真JPEG压缩对摄影测量点定位精度的影响是显著的。随着压缩比的增大，影像可视化质量逐渐衰减，像点量测精度不断降低，加密点位精度几乎呈线性趋势下降，且高程比平面衰减的速度要快得多。

According to self-calibration bundle block adjustment, a mathematical model which solutes exterior orientation elements of the new imageries by using fixed imageries in the same area is set up at first. The orientation parameters of the fixed imageries are previously obtained. Several sets of aerial imageries at different scales are simulated based on a piece of DOM (Digital Orthophoto Map) with a scale of 1:50, 000 and corresponding DEM (Digital Elevation Model) with the interval of grid being 100 meters of some certain area. Finally, the exterior orientation elements of these new imageries and 3D coordinates of photogrammetric points are calculated by combined bundle block adjustment with the derived mathematical model. The empirical results show that the exterior orientation elements and the coordinates of the photogrammetric points are identical between the mentioned method and the conventional bundle block adjustment for the two periods of imageries at the same scale. However, when the image scales are different the adjusted accuracy has an apparent decrease but can still meet the specification of topographic maps. The experiment has verified that the determination of the orientation parameters of the new imageries by using the fixed imageries is correct in theory and is feasible in practice. And the accuracy of 3D coordinates of the hotogrammetric points, which are purely gained by combined adjustment with two periods of imageries, satisfies the requirement of the specification of topographic maps. That is to say, aerial riangulation without ground control points (GCPs) can be truly realized. It will have glory pplication future on the map revision,the update of geographic spatial information database and automatic change detection of multi-temporal imageries.

本文利用武汉测绘科技大学自行研制的摄影测量与非摄影测量观测值联合平差程序WuCAPS系统对天津蓟县某测区一组实际GPS 控制飞行的航摄像片进行了处理。针对GPS辅助空中三角测量中的若干问题，如构架航线的敷设、地面控制点的布设、无地面控制空中三角测量的精度等，进行了研究。通过对测区进行GPS辅助光束法区域网平差计算得到了与国外相同的研究结果。此外，文中还对如何实施GPS辅助空中三角测量提出了实用建议。

本文简要介绍了GPS辅助光束法区域网的基本原理和方法，详细讨论了太原航摄机动态试验场实际GPS航摄飞行试验的结果。利用联合平差程序WuCAPS系统时对试验区进行GPS辅助光束法区域网平差，用分米级精度的GPS摄站坐标获得了实地上平面为士7.9cm、高程为士18.1era的加密精度，充分显示了动态GPS定位技术在航空遥感定位中的广阔应用前景。