Weekly Seminar: “2D and 3D Imaging using Ground Noise SAR”
In the talk implementation of millimeter-wave SAR tomography technique based upon Multiple-Input-Multiple-Output (MIMO) principle with time-division of signals in Tx/Rx channels. We briefly describe MIMO operational mode for 2D aperture synthesis, which has been implemented with the help of Ka-band (36.5 GHz) Ground Based Noise Waveform SAR (GB NW SAR), and Antenna with Pattern Synthesizing.
In our case, tomographic 3D imaging is done via illumination of an object of interest with a wideband random/noise signal enabling high enough range resolution (defined by the power spectrum bandwidth B : , where c is the velocity of light), and in combination with formation of 2D aperture for getting cross-range (angular) resolutions required. Having the reference signal sampled we can vary its delay and thereby perform range focusing. This enables generation of 2D images (tomographic slices) for every range bin inside transparent object in the scene. In this way, application of noise waveform with wide enough power spectrum bandwidth enables layer-by-layer visualization of a semitransparent scene and, therefore, generation of its tomographic 3D image.
Usually, for implementing of 2D aperture synthesis a mechanical motion of Tx and/or Rx antennas over a planar synthetic aperture is used along with performing transmission and reception of signals at the grid nodes. Positioning system for such 2D movement may be complex and expensive. We suggested formation of virtual 2D synthetic aperture via moving of both Tx and Rx antennas along orthogonal directions. 2D scan is done in the following way: Tx antenna takes the first position, and Rx antenna performs SAR scan along horizontal path. After that, Tx antenna is displaced to another position along vertical path, and a new SAR scan is performed by the Rx antenna. Every scan of the Rx antenna enables generation of a 2D image in the plane of Rx synthetic aperture. Those images for different Tx antenna positions will contain information on phase shift of the signal due to movement of the Tx antenna phase center which may be used for cross-range (angular) compression.
In this way, application of MIMO 2D aperture synthesis and Noise Radar provide both angular and range resolutions and, therefore, enables tomographic 3D imaging which will be described in the talk.
Prof. Konstantin Lukin received his diploma in Radiophysics & Electronics from Kharkov State University, Ukraine, in 1973. He is Head of the Laboratory for Nonlinear Dynamics of Electronic Systems, LNDES, at IRE NASU. He completed his Candidate of Sciences thesis in IRE NASU and defended it at Moscow State University (MSU) in 1980. He completed his Doctor of Sciences dissertation in Physical Electronics in IRE NASU and defended it at Kharkov State University in 1989. He has been a visiting scientist at the International Center for Theoretical Physics (ICTP, Trieste, Italy) in 1996-1997 and a visiting professor at the Joint Research Center (JRC, Ispra, Italy) in 1997-1998. His current research interests are as follows: generation and processing of random/chaotic/noise signals and their applications in Noise Radar for SAR imaging, differential interferometry; microwave monitoring of urban areas and detection of pre-catastrophic states of large natural and manmade objects, such as landslides, bridges, TV towers, dams, large building, hangars, etc. He is Co-Chairman of RTO/NATO Task Group on ‘Space and Frequency Diverse Noise Radar’. Dr. Lukin is author or coauthor of more than 260 journal publications and 2 monograph. He is a TPC member of the EUSAR, IRS, SPSympo, IRMMW-THz, MSMW, IEEE IVEC and Chairman of NRT-2002, 2003, 2012 International Conferences. He was leader of many international R&D projects on Noise Radar systems and sensors; on SAR imaging and microwave monitoring of environment. Currently he is leader of Ukrainian part of the SCOUT Project under FP-7 Program and Project under NATO SfP Program.