中文摘要：

针对Ⅱ类病态性问题是测绘实践中较为普遍存在的问题，如何正确诊断出所有观测向量的整体病态性及个别观测向量对Ⅱ类病态性的影响是有效求解未知参数的前提，提出一种基于投影矩阵的观测向量影响诊断方法，并结合实例论证了基于投影算子诊断观测向量对Ⅱ类病态性影响的有效性。

英文摘要：

Class Ⅱ ill condition problem are universal in surveying practice. How to diagnose ill condition and determine the effect of individual observation vector on ill condition is the precondition of finding unknown parameters effectively. A diagnosis method based on projection matrix observation vector effect on class Ⅱ ill condition is presented and proved in this paper. The effectiveness of this method is proved by example.