中文摘要：

Klobuchar模型基本能反映电离层的时空变化特性,但该模型固定了初始相位以及夜间时延值,给模型引入了误差。因此,以电离层双频改正模型为背景场,利用中国境内外IGS站实测数据的准确性,不断改正Klobuchar模型的初始相位、夜间时延值和振幅,从而建立中国地区电离层延迟模型,并对改进的Klobuchar模型在中国地区的精度进行评估以及适用情况分析。结果表明：改进的Klobuchar模型精度显著提高,适用于中国地区在不同时空环境下的电离层模型建立。

英文摘要：

Klobuchar model reflects the temporal and spatial variation of the ionosphere basically, but the initial phase and the delay values set at night as a constant value will bring in partial errors. The regional ionospheric model is established by the data from IGS stations in China. The data are used to correct its initial phase, delay values at night and amplitude constantly based on the accuracy of them. Hence, the accuracy and the applica-bility of the improved model are to be evaluated and analyzed. The results show that the accuracy of Klobuchar model is improved significantly, and can be applied to the establishment of ionospheric model at different tempo-ral and spatial environment in China.