传统脉冲干涉测距只能测量离散的长度值，提出了一种利用飞秒光频梳进行任意长绝对测距的方法，建立了多脉冲干涉的时间相干模型，分析了被测距离与多脉冲干涉条纹峰值点位置变化的关系，研究了大气条件的改变对测距结果的影响。模拟结果表明：多脉冲干涉条纹峰值点位置的偏移具有周期性，在一个周期内呈单调性改变；温度和湿度的改变与多脉冲干涉条纹的峰值间距的改变呈正比，而气压和二氧化碳含量的改变与多脉冲干涉条纹的峰值间距的改变呈反比。该分析结果对于在空气中进行长距离绝对测距具有重要意义，可利用建立的模型进行误差补偿，以提高测距精度。

In order to solve the problem of the difficulties in obtaining consecutive values by the pulse interferometry method, a method of multiple pulse interferometry by using femtosecond optical frequency comb is proposed for the arbitrary and absolute length measurement with high precision. The main principle of the arbitrary and absolute length measurement on the basis of multiple pulse interferometry is expounded, and then the temporal correlation model of multiple pulse train interference fringes is constructed. The peak position shift which can contribute to the distance is analyzed. The effect of dispersion on the correlation fringes is also analyzed. In addition, the effects of the atmosphere environmental variations including temperature, humidity, air pressure, and CO2 content on the air refractive index, which affects the measuring precision, are simulated. The simulation results show that the shift of the peak position of the multi-pulses interference fringes is periodic and monotonous in a period. The change of temperature and humidity is proportional to the change of the peak distance of the multipulse interference fringes，while the change of air pressure and CO2 content is in opposite.