Microwave imaging approaches generally require the knowledge of the complex incident field distribution inside the imaging domain. This task can be accomplished by probing the observation domain, thus resulting in a time-consuming process, or assuming a numerical/simulated model. Alternatively, the incident field can be collected on the measurement domain, and the field distribution can be successfully retrieved on the whole imaging space. In this paper, a full phaseless, two-step strategy is described, where the phase of the incident field is retrieved by exploiting a spatial domain indirect holography technique, applied to the acquisition points only. The retrieved complex incident field can be so used for the reconstruction of the incident field inside the domain of interest. More specifically, a modal expansion technique and a source reconstruction method are adopted and compared to perform the above task. Once performing the characterization of the incident field distribution, the proposed strategy is included in the framework of a phaseless inverse scattering problem, where intensity-only data of the total field are involved. The effectiveness of the combined approach is demonstrated by considering an imaging scenario which involves a series of breast models as inhomogeneous targets.

中文翻译：

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空间域间接全息术用于生物医学微波成像的完全无相方法


微波成像方法通常需要了解成像域内复杂的入射场分布。该任务可以通过探测观察域来完成，从而导致一个耗时的过程，或者假设一个数值/模拟模型。或者，可以在测量域上收集入射场，并且可以在整个成像空间上成功地检索场分布。本文描述了一种完整的无相位、两步策略，其中通过利用仅应用于采集点的空间域间接全息技术来检索入射场的相位。检索到的复杂事件场可以用于重建感兴趣域内的事件场。更具体地，采用模态扩展技术和源重构方法并进行比较来执行上述任务。一旦执行了入射场分布的表征，所提出的策略就包含在无相逆散射问题的框架中，其中涉及总场的仅强度数据。通过考虑涉及一系列乳房模型作为不均匀目标的成像场景，证明了组合方法的有效性。