forward azimuth meaning in Chinese

前方位角
正向方位角

In the first step . 2861 surface wave recordings with seismic magnitude over 5 . 0 are selected under the criteria of good - wave and " intact recording " , calculating the big - circle paths , and then about 284 two - station pairs of which two stations are along the same big - circle are chosen , among them there are about 260 pairs with difference of forward azimuth angle less than 5 ? . after further optimizing , 223 pairs which perfectly cover the china area are used in the final calculation
本文首先从所收集的震级在5级以上2861条面波记录中挑选波形好、记录完整的资料进行预处理，计算其大园路径，从中挑选出位于同一地震大园路径上的双台地震记录约284对，然后计算出前向方位角差，其差在5范围以内的双台地震记录约260余对，量后对这些记录进一步优化，选出223对对中国大陆地区覆盖比较好的面波记录。