分别选用负荷模型方法、GRACE模型方法、空间加权法和多核函数法分析GPS垂向年周期运动参数的精确获取问题,以云南26个陆态网络GPS连续站2010—2015年观测数据得到的垂向年周期参数为标准,评估了这4种方法的效果。这4种方法与GPS连续站实测的振幅差异平均值分别为4.97,3.31,1.38,1.43 mm,4种方法的WRMS减速比平均值分别为0.70,0.84,0.95,0.94。结果 表明:由于云南地区GPS连续站密度较高且区域垂向年周期运动空间一致性较好,空间加权法和多核函数法效果最好,GRACE模型方法次之,负荷模型方法最差。建议在GPS连续站较多的区域,采用空间加权法或者多核函数法; 在GPS连续站较少的区域,建议采用GRACE模型方法。
For the accurate acquisition of annual vertical motion parameters based on GPS,four methods are used,namely the load model method(based on vertical displacements from Global hydrology loading model),the GRACE model method(based on vertical displacements from GRACE solution),the spatially weighted method and the multi-surface function method(those are used for spatial interpolation of the annual vertical motion parameters inferred from continuous GPS(cGPS)station).Then,the annual vertical motion parameters obtained from 26 cGPS stations for the period 2010—2015 in Yunnan were used as criteria to evaluate the effects of these four models.The average amplitude difference between the four methods and the GPS continuous station is 4.97,3.31,1.38,and 1.43 mm.The average WRMS reduction ratio of the four methods is 0.70,0.84,0.95,and 0.94.The results show that:due to the high density of cGPS stations and the spatial consistency of annual vertical motion in Yunnan,the spatial weighted model and the multi-surface function model are the best.The GRACE model is the third and the load model is the worst.Therefore,it is suggested that the spatially weighted models or the multi-surface function models should be used in areas with dense cGPS network,and the GRACE models are recommended in areas where cGPS stations are not abundant.
