针对GNSS载波相位精密定位中的整周模糊度解算问题,引入格基规约的思想,基于系统旋转的Householder正交变换对现有的LLL规约算法进行了改进,并将长度规约的比较范围扩大到n维,对规约基向量进行预排序,提出了HE-LLL规约算法。在不同观测时段长度和不同基线长度的情况下,分别从条件数、规约时间、非正交化指标以及正交化列向量长度变化趋势等方面将HE-LLL规约算法与改进前算法的规约效果进行了比较,结果表明,HE-LLL算法大大提高了规约效率,且对正交化列向量的长度具有很好的约束作用。
A new lattice reduction method is introduced to solve the problem of integer ambiguity resolution in GNSS carrier phase precise positioning. The current LLL reduction algorithm is improved based on a orthogonal Householder transformation with systematic rotation. The comparative range is extended to n. The reduction base vectors are preordered and a HE-LLL reduction algorithm is proposed. Experiments with different time intervals and baseline lengths were executed and a comparison was made between the HE-LLL algorithm and other algorithm concerning condition number, non-orthogonal index, reduction time, and changing trend of the length of orthogonal row vector. The results show that the HE-LLL algorithm has improved reduction efficiency, and can well restrict the length of orthogonal row vector.