介绍低纬电离层CT实验所使用的数据自动采集系统并提出一种电离层CT算法。在数据采集过程中引入了GPS标准时间；重建算法的特点是利用差分多普勒频率数据避免了相位积分常数的计算，提高了对较弱的电离层扰动和不规则结构的检测能力。数值模拟反演结果表明了该算法对电离层CT重建的有效性，并给出有关实测数据的重建结果。

This paper presents the design and operational features of the automatic data acquisition system for the lowlatitude ionospheric tomography along the 120oE meridian. An improved reconstruction algorithm of computerized ionospheric tomography is also proposed. The algorithm avoids the calculation of integral phase constant by exploiting the differential Doppler frequency data￡?thus its capability of detecting weaker ionospheric irregularities has been enhanced. Both numerical simulated examples and the reconstructed results from observed data show that the new algorithm works reasonably and effectively with ionospheric CT problems.