Mária Gamcová

Imaging method: A strong tool for moving target tracking by a multistatic UWB radar system

In this paper, imaging method for moving target tracking by a multistatic ultra-wideband radar system is described. The task of moving target tracking consists in estimation of a target trajectory based on processing of raw radar data obtained from all receiving channels of a radar system. Then, the imaging method applied for target tracking consists of such signal processing phases as raw radar data pre-processing, background subtraction, fusion of the data obtained by receiving antennas of a radar, detection, localization and tracking itself. The performance of the imaging method described in this paper is demonstrated by signal processing obtained by M-sequence UWB radar for a scenario represented by through wall tracking of a single moving target. The obtained results confirm the excellent performance of the discussed method.

Sea Wind Measurement by Doppler Navigation System with X-Configured Beams in Rectilinear Flight

We suggest a conceptual approach to the measurement of the near-surface wind vector over water using a Doppler navigation system, in addition to its standard navigation capabilities. We consider a Doppler navigation system with a track-stabilized antenna and x-configuration of its beams. For the measurement of the sea-surface wind, the system operates in the multi-beam scatterometer mode in rectilinear flight. The proposed conceptual design has been validated, and its accuracy for the wind vector measurement has been estimated using Monte Carlo computational simulations.

Algorithm of traffic signs recognition based on the rapid transform

This paper presents a model of a system for invariant object recognition, which consists of five stages. The first stage shifts the object so that the centroid of the object coincides with the center of the image plane. The second stage is an application of the polar-coordinate transforms used to obtain N-dimensional vectors-representations of the input object. In this stage, any rotation of the input object becomes a cyclic shift of the output value of this stage. The third stage employs CT (Certain Transform), a class of shift-invariant transformations to provide invariant representations for cyclically shifted inputs. The next stage normalizes the outputs of the previous stage to obtain scale invariance. The final stage realizes a classification.

On off-nadir wind retrieval over the sea surface using APR-2 or similar radar geometry

ABSTRACT In some cases, nadiral wind retrieval algorithms are not applicable for wind measurements due to the specificity of a radar instrument measuring geometry or its mounting on aircraft, and so off-nadir backscattering measurements can only be performed. In this paper, a method for off-nadir wind retrieval over the sea based on the sea-surface backscattering measurements with the Airborne Precipitation Radar-2 or similar radar measuring geometry has been proposed. The study is based on a theory of the quasi-specular microwave backscattering from the sea surface. An anisotropic water surface approach is considered. The wind vector is retrieved from the system of equations for measured normalized radar cross sections (NRCS) by using the relationships between the speed of the sea-surface wind and the standard deviations of the sea-surface slopes along the up- and cross-wind directions. A wind vector recovery with the cross-track scanning measurement geometry has been simulated. The maximum errors of the wind speed and direction estimations are within typical errors of wind measurements by a scatterometer. A maximum altitude of the method applicability for this geometry has been defined. Recommendations to perform the measurements have been described in detail.

Alternative antenna measuring methods with use of impulse UWB radar

This paper presents alternative methods of measuring the electric properties of antennas. In this case, the UWB impulse radar system is used. Also, the paper describes a relatively low cost measuring system, its calibration, verification and calculation methods of the required parameters - return loss and radiation pattern. All experimental results obtained by UWB radar are compared with the results obtained by measurements in an anechoic chamber. Experimental results of the measurements using UWB impulse radar system show good agreement with the simulated performance and with the measurements in the anechoic chamber.