100kHz地波计算中大地等效电参数和等效地球半径选取的探讨  

A Discussion on the Selection of Equivalent Ground Electric Parameters and Equivalent Earth Radius in Calculation for 100kHz Ground Wave Project

作　　者：梁仲寰[1] 

机构地区：[1]中国科学院国家授时中心,陕西省临潼710600

出　　处：《陕西天文台台刊》2002年第2期90-100,共11页Publications of The Shaanxi Astronomical Observatiory

摘　　要：在100kHz地波工程计算中,通常将E_0称为基准场强,t_w称为二次相位因子。笔者将1022所计算(简称之为算法1)的E_0和t_w和陕西天文台计算(算法2)的E_0和t_w与12个地波观测地点测得的基准场强E_0和二次相位因子t_w做了比较。基本做法是:由E_0^(测)通过算法1得到的E_0～σ和t_w～σ(σ为大地电导率)曲线,导出对应于E_0^(测)的二次相位因子,称之为t_w^(导)(F);对算法2用同样做法亦得相应的t_w^(导)(C),求二次相位因子实测值与导出值之差:△ (F)=t_w^(测)-t_w^(导)(F)和△(C)=t_w^(测) -t_w^(导)(C)。结果是:有8个观测点△(F)和△(C)一致;有两个观测点|△(F)|明显大于|△(C)|;有一个观测点|△(F)|为|△(C)|的3倍多;有一个观测点,t_w^(测)与t_w^(导)(C)吻合得很好,而t_w^(导)(F)无法确定。由此可见,在我国的实际条件下,对于100kHz的地波工程应用,算法2要比算法1好。E0 And tω are usually called fundamental field intensity and quadric phase factor respectively in the calculation for 100kHz ground wave project. In this paper the values of E,, and tω estimated by the method '1' of the 1022 Institute and those estimated by the method '2' of the National Time Service Center are compared respectively with the results of fundamental field intensity E0exp and quadric phase factor tωexp , which are obtained from the experiments conducted at 12 ground wave observation points. The basic procedure is as follows: The curves of Eo ~ σ (ground conductivity) and tω ~ σ are obtained by the method '1', and tωd,(F) , the values of quadric phase factor corresponding to Eoexp ,are derived from Eoexp via those curves. In the similar way the values of quadric phase factor corresponding to E1'^' for the method '2', tωd(C) ,can be derived.The differences A (F) = tωexp - tωd(F) and A (C) = tωexp - tωd(C) are then estimated. The results show that A (F) and A (C) coincide with each other for 8 observation points, | A(F) | is explicitly greater than |△(C) | for 2 observation points, | △ (F) | is more than 3 times greater than | △ (C) | for one observation point, and tωexp is almost equal to tωd(C) while tωd(F) can not be determined for one observation point. It seems that the method'2'is better than the method'1'in the calculation of 100kHz ground wave project for the practical condition of the continent of China.

关 键 词：地波场强 大地等效电参数 等效地球半径 低频地波传播 二次相位因子 

分 类 号：P319[天文地球—固体地球物理学]