Outdoor multi-polarization passive millimeter–wave imaging via integrated W-band dual polarization direct detection radiometer

we describe the design and phenomenology imaging results of an integrated W-band dual polarization direct detection radiometer developed by ‘TeraFuture laboratory’ for outdoor multi-polarization passive millimeter-wave (PMMW) imaging. Operating from 75GHz~110GHz, the integrated W-band radiometer, which shows a high level of integration and is easy-to-use, has two same channels while each channel can receive two orthogonal polarization states of the incident millimeter-wave (MMW) radiation simultaneously. Based on the radiometer, an outdoor multi-polarization PMMW image system has been build, whose image angular resolution is less than 0.4°. Multi-polarization measurements are realized by rotating the detector around the observation axis direction. A large outdoor area has been imaged, which include the buildings, vegetative cover, personal cars and cement road, egg. Various polarization parameter images are generated to analyze the polarization characteristics and the images are compared between in and after the rain. The results show that the multi-polarization imaging has the great potential for remote sensing.