Estimation of the 3D spatial location of non-line-of-sight objects using passive THz plenoptic measurements

At THz frequencies, many building materials exhibit mirror-like reflectivity, greatly facilitating the 3D spatial location estimate of non-line-of-sight objects. Using a custom THz measurement setup that employs a high sensitivity room temperature THz sensor, we measure the spatial and angular components of the radiation from hidden objects scattered from rough walls. The three-dimensional location of a thermally elevated object can then be determined using this "light field" information together with a refocusing algorithm. We experimentally demonstrate accurate location estimates of human-like NLOS objects in realistic situations.