机载三线阵传感器航空摄影测量的坐标转换方法研究

由于机载GPS获取的数据是WGS84坐标系,定向测图时首先要进行坐标转换。本文讨论了7参数平面转换模型与GPS水准测量拟合高程异常的方法,研究了数字航空摄影测量的像控点布设问题,并对数字航空摄影测量只在测区四角布设控制点即可满足空三精度要求的观点进行了分析。实验结果表明,机载三线阵航空摄影测量中高精度的7参数转换与似大地水准面精化成果是获取高精度空三的前提。

Research on datum transformation for the aerial photogrammetry of airborne three-line CCD scanner

The combined block adjustment principle for airborne three-line CCD scanner was introduced first.Because of the use of GPS/IMU,the datum transformation is an inevitable problem.The horizontal coordinate transformation is implemented by seven ellipsoidal parameters and the vertical coordinate transformation is defined by the regularly spaced vertical shifts between the WGS84 ellipsoid and the local geoid height.On the number of GCP used for aerial triangulation of three-line CCD scanner,the paper pointed out that four ground control points around the corners of the block area are enough to calculate the seven ellipsoidal parameters which can be used to perform horizontal coordinate transformation.The experimental results showed that the high accuracy of the seven ellipsoid parameters and the geoid shifts were the precondition of good aerial triangulation results in the aerial photogrammetry of airborne three-line CCD scanner.