在科学研究和生产活动中,或是由于待观测的量不便于进行直接测量,或是为了获得高精度的观测结果,人们常以间接测量来实现观测。即先以直接测量的方式测得若干个其他物理量Xj的观测值x_j(j=2,3,…,m),然后将这些观测值作为自变量代入到一个依据物理定律、基本物理公式或数学定理 In scientific research and production activities, either direct measurement is not convenient because of the amount to be observed or in order to obtain high-precision observation results, observations are often made by indirect measurement. That is to say, the observed values ​​xj (j = 2,3, ..., m) of several other physical quantities Xj are measured by direct measurement, and then these observations are taken as independent variables into a physical law, basic physical formula or mathematics theorem