结合单色频率绝对相位算法仿真分析了空间低相干干涉条纹信噪比对解调中干涉级次和绝对相位的影响，仿真结果显示，当条纹信噪比大于18 dB时，可避免干涉级次跳变问题，此时解调得到的绝对相位标准差随信噪比的增加呈线性减小趋势，在25 dB信噪比下其值可达到0.023 rad。通过改变光源强度进行了不同信噪比对解调影响的实验研究，实验结果与仿真分析结果基本一致。另外，压力解调实验结果显示，解调误差随信噪比增加而降低，在24.79 dB信噪比下压力解调误差为0.044 kPa，相比18.10 dB信噪比降低了2.84倍。实验结果表明，在5~150 kPa压力范围内，为保证0.05%F.S.( F.S.表示全量程)的解调精度，则信噪比应大于22 dB。

The influence of signal-to-noise ratio (SNR) of spatial low-coherence interference on demodulated interference order jump and absolute phase, combining with monochromatic frequency absolute phase demodulation algorithm，is simulated and analyzed. The simulation result shows that it can avoid interference order jump when SNR exceeds 18 dB. In this case, standard deviation of demodulated absolute phase decreases linearly with the increase of SNR, and the value of standard deviation with SNR of 25 dB drops to 0.023 rad. The experiment about the influence of SNR on pressure demodulation is investigated through changing optical source intensity, and the experiment result is consisted with the simulation analysis. Pressure demodulation experiment shows that demodulation error decreases with the increase of SNR. Pressure demodulation error is 0.044 kPa when SNR reaches up to 24.79 dB, reduced 2.84 times compared to that with SNR of 18.10 dB. Experiment results indicate that when the pressure is in the range from 5 to 150 kPa, only the value of SNR is greater than 22 dB, and the demodulation accuracy can meet 0.05% F.S.，where F.S. is full scale.