Stafford Jason W, Duncan Bradley D, Rabb David J
Appl Opt. 2016 Jun 10;55(17):4611-20. doi: 10.1364/AO.55.004611.
Three-dimensional (3D) holographic ladar uses digital holography with frequency diversity to add the ability to resolve targets in range. A key challenge is that since individual frequency samples are not recorded simultaneously, differential phase aberrations may exist between them, making it difficult to achieve range compression. We describe steps specific to this modality so that phase gradient algorithms (PGA) can be applied to 3D holographic ladar data for phase corrections across multiple temporal frequency samples. Substantial improvement of range compression is demonstrated with a laboratory experiment where our modified PGA technique is applied. Additionally, the PGA estimator is demonstrated to be efficient for this application, and the maximum entropy saturation behavior of the estimator is analytically described.
三维（3D）全息激光雷达利用具有频率分集的数字全息术来增加在距离上分辨目标的能力。一个关键挑战在于，由于各个频率样本不是同时记录的，它们之间可能存在差分相位像差，这使得难以实现距离压缩。我们描述了针对这种模式的特定步骤，以便相位梯度算法（PGA）能够应用于3D全息激光雷达数据，对多个时间频率样本进行相位校正。通过应用我们改进的PGA技术的实验室实验，展示了距离压缩的显著改善。此外，证明了PGA估计器对于此应用是有效的，并且对估计器的最大熵饱和行为进行了分析描述。
