高精度地震绝对位置是地震成灾范围预估、内部结构成像、地震构造研究等工作的关键参数之一。然而在稀疏台网情形下，很难只通过地震波到时方法获取高精度绝对位置。新近研究提出可以利用背景地震噪声实现稀疏台网中高达2-3公里精度的地震绝对定位，但该研究尚很不系统。针对影响基于背景噪声进行地震绝对定位精度的不同因素，选取三个已知真实地表位置的中小地震事件进行为期两年的流动台阵观测，评估背景噪声地震定位方法的准确度，分析震源地理位置（到海洋的距离及地形起伏程度）、观测时间长度和季节、台站数量及分布、近台与震中距离等因素对定位精度的影响，进一步完善稀疏台网条件下的中小地震高精度绝对定位的方法，探讨NCF中EGF的准确性，为稀疏台网地区的高精度地震定位提供可靠方法。

ground truth location of earthquakes are essential for early warning of seismic hazard, seismic tomography and seismo-tectonic studies. However, it is very challenging to achieve high accuracy location with sparse seismic networks. Recently ambient seismic noise has been demonstrated to be able to achieve 2km accuracy of earthquake location. We propose to install portable seismic arrays around three ground truth (GT1) earthquakes, and investigate effects upon location accuracy due to number of stations, distance of station from events, azimithal gap as well as seasonality of observation, so that we can enhance location accuracy with the method ambient seismic noise location.