K. A. Lukin

W-band noise radar sensor for car collision warning systems

The possibility of development of radar sensors for car collision warning systems on the basis of noise radar technology has been shown. Testing shows fast enough processing of radar return, sufficient for displaying information obtained in real time. The system developed possesses high EMC and EM interference immunity.

Coherent imaging in the range-azimuth plane using a bistatic radiometer based on antennas with beam synthesizing

Radiometric monitoring allows us to obtain information about thermal electromagnetic radiation of objects in the chosen frequency band. Imaging of distant targets using their thermal electromagnetic radiation may be implemented with the help of bistatic radiometric systems. These systems are based upon measurement of the time difference of arrival of the radiation received by two or more antennas [1]-[3]. This approach has been developed in long wave radar astronomy to improve angular resolution of telescopes [4], [5].

Radar tomography using MIMO noise radar with signals time-division in transmit/receive channels

We describe MIMO approach to implementation of radar tomography and present preliminary results of its experimental validation using Ka-band noise waveform ground based SAR. The range resolution in radar tomography is determined by power spectrum width of the transmitted signal, while cross-range resolutions are defined by 2D aperture dimensions. We apply MIMO concept with time-division to emulate 2D aperture synthesis combined with range resolution due to wideband random signals which enables generation of 3D coherent radar images. Two linear synthetic apertures have been used for transmit and receive antennas oriented in vertical and horizontal directions, respectively.

Phase measurement accuracy in noise waveform synthetic aperture radar

Detection of small changes in natural formations and human-made constructions is a promising application of synthetic aperture radar (SAR). This paper deals with a specific radar, which is a ground-based SAR using noise waveform. Being fully coherent, SAR provides both phase and amplitude information for every pixel in the mapped area. This gives rise to the possibility of comparing phases between the images taken from the same position at different times in order to extract information about the changes that have occurred between subsequent radar measurements. Such a technique, called coherent change detection (CCD), allows changes of a subwavelength size to be detected. The use of a noise waveform for sounding ensures high electromagnetic compatibility and interference immunity. Moreover, it enables long integration time in the detection stage. However, the random nature of probing signals used in noise radars leads to randomness of the output signals and the preservation of residual fluctuation in the images generated. This random residual, along with external noise, influences the overall accuracy of the phase measurement in noise radar. In this paper, the theoretical and experimental investigation of this specific influence of noise on the precision of phase measurements is presented. The theoretical part of the paper is focused on the estimation of the Cramer-Rao lower bound for the phase measurements using both statistical theory and geometrical interpretation of complex signals. In the experimental part, these findings are verified with dedicated measurements of a metallic sphere displacement, carried out with the help of a ground-based noise waveform SAR.

Radar tomography via time-division MIMO noise radar

MIMO approach to implementation of radar tomography is described and preliminary results of its experimental validation using Ka-band noise waveform ground based SAR are presented. MIMO concept with time-division to of Tx/Rx channels is applied to emulate 2D aperture synthesis combined with range resolution due to wideband random signals. Two linear synthetic apertures have been used for transmit and receive antennas oriented in vertical and horizontal directions, respectively. Range resolution in radar tomography is determined by power spectrum width of the transmitted signal, while its cross-range resolution is defined by 2D aperture dimensions. This enabled generation of 3D coherent radar images in radar tomography mode.

Radar tomography using MIMO noise radar and antenna with beam synthesis

Conventional SAR generates 2D image using combination of range compression and 1D aperture synthesis. The range resolution of such approach is determined by the signal spectrum width, while cross-range resolution is defined by the synthetic aperture length. 2D aperture synthesis implies movement of antenna along 2D aperture and cross-range compression technique in both dimensions to obtain resolution along two angular coordinates. In combination with pulse compression it gives 3D resolution. We suggest using MIMO principle in combination with SAR approach to generate 3D coherent radar images. For that, two linear synthetic apertures used - one for transmit antenna and another for receive one. Spatial scanning with those antennas is performed in the way which provides data similar to the ones obtained from 2D scanner. The paper describes the approach and presents results of its experimental test using Ka-band noise waveform ground based SAR.