中文摘要：

脉冲星计时观测能够精确测量脉冲星自转参数和天体测量参数．概述了脉冲星计时模型和利用最小二乘拟合测量脉冲星各个参数并估计其方差的数学方法．在黄道坐标系导出了脉冲星各个参数误差与计时残差之间关系的数学表达式．给出了脉冲星黄经、黄纬和周年视差测量精度与脉冲星黄纬绝对值之间的关系曲线．讨论了脉冲星各个天体测量参数测量精度与脉冲星纬向参数本身的关系．

英文摘要：

Pulsar rotational and astrometric parameters can be measured with a very high precision by pulsar timing observations. The pulsar timing model, the estimation method of pulsar parameters and their covariances by least square solution are briefly described. The relationship between the timing residuals of a pulsar and errors of its rotational parameters is denoted with the polynomial of time. The relationship between the timing residuals of a pulsar and errors of its astrometric parameters can be derived from the Roemer delay due to the Earth motion around the solar system barycenter. The mathematical expressions for the relationship between timing residuals and errors of pulsar astrometric parameters adopted for timing solution are derived within the ecliptic coordinate reference system using the transformation from analytical vector expression of the Roemer delay to the corresponding spherical coordinate expression. The precision of pulsar astrometric parameters determined by timing observation is dependent on the absolute ecliptic latitude of pulsar. For the pulsar located close to the ecliptic plane, it is difficult to precisely measure the pulsar latitude parameter by timing observations. For the pulsar located close to the ecliptic pole, it is difficult to precisely measure the pulsar longitude and annual parallax parameters by timing observations. The precision of pulsar ecliptic coordinate and annual parallax parameters determined by timing observations versus pulsar absolute ecliptic latitude is shown. The relationship between the precision of proper motion parameters of pulsar measured by timing observations and pulsar absolute latitude is also discussed.