The article proposes a solution of a problem of polarization error compensation for radar object direction finding by means of conical scan method. The solution is considered at signal processing level that makes possible to avoid polarization limitations in antennas engineering. The purpose of the article is to substantiate a model for polarization-induced errors by conical scan direction finding method and to develop an algorithmic technique for the considered method correction with regard to arbitrary polarization conditions of radar interaction. The results are presented by analytical model along with quantitative estimates of polarization-induced errors of direction finding and the computational procedure of the error compensation as well as by analysis of imperfectness factors for the proposed procedure exposing its practical applicability.

Разработано аналитическое описание информационного сигнала в РЛС с коническим сканированием, расширенное на случай угловых эволюций равносигнального направления. В гармоническом приближении характера эволюций получены количественные оценки их влияния на качество пеленгования.

The paper considers a generalized case of conical scanning method, in which the cross‑section of the antenna beam has an elliptical shape. Such feature of the antenna beam shape leads to the occurrence of additional information contained in the received signal. It is shown that by utilizing this information it is possible to form an estimate of the direction to object at large off‑center angles. A modification of the conical scanning method is proposed that combines the estimates of object’s angular position, obtained via standard computational procedure (main scale) and additional procedure for angle estimation based on the additional direction‑finding information contained in the received radar signal envelope (additional scale). The technical result of the introduced two‑scale modification of the conical scanning method consists in a significant expansion of the operational area of direction finding compared to the original method.

An attribute of modern robotic systems and control systems for unmanned vehicles is a machine vision, which is based on processing of images obtained from highly informative radar or optoelectronic sensors. Effective image processing and recognition procedures are based on use of morphological features of objects images with high space‑time stability. This paper considers one of the aspects of images morphological analysis related to the influence of errors in the reference contour descriptions of objects. With use of developed analytical apparatus it is shown that the result of such errors is a decreasing of object/background contrast and, as a result, increasing of image comparison errors. The degree of this increase depends on the object type (area, linear) and its characteristics (size, contrast). Practical recommendations on the acceptable level of errors in the representation of object descriptions are justified.

Statistical analysis method and its results are presented for a two-scale modification of the conical scanning direction finding method generalizing it for a case of elliptical cross-section of antenna beam. In order to utilize additional positional information that is excluded in a typical implementation of conical scan method, a two-scale procedure is proposed for estimating the direction to object. It is shown, that application of this procedure does not lead to worsening of the accuracy of object’s coordinates estimate near boresight axis and also attains a significant increase of angular operating area of direction finding due to the increase in number of harmonics of conical scanning frequency included in processing. Analytical expressions are obtained and discriminator and fluctuation curves are calculated, revealing the possibilities to increase the angular operating area of direction finding depending on signal-to-noise ratio and ellipticity of antenna beam’s cross-section.