Development of a method for estimating the effect of transformation of the normalized frequency mismatch function of a coherent bundle of radio pulses on the quality of radar frequency resolution

The necessity of studying the influence of the transformation of the frequency mismatch function of a coherent bundle of radio pulses on the quality of solving the radar frequency resolution problem is substantiated. This solution determines the effectiveness of radar observation of high-speed and maneuvering individual and group aerodynamic objects. The method is based on explicit expressions for calculating the normalized frequency mismatch function of a coherent bundle of radio pulses, taking into account its transformation due to the radial motion of high-speed and maneuvering individual and group aerodynamic objects. The estimation of the potential frequency resolution of bundles with different numbers of radio pulses with typical parameters for a coherent pulse radar is carried out. Possible values of frequency resolution under the additive effect of uncorrelated internal noise of the radar receiver and the multiplicative effect of correlated phase fluctuations of the radar signal are estimated. With an insignificant multiplicative effect of correlated phase fluctuations, a twofold increase in the number of radio pulses in a bundle provides an improvement in the frequency resolution (reduction of the width of the normalized frequency mismatch function) by 100 %. With the predominant multiplicative effect of these fluctuations, a twofold increase in the number of radio pulses results in an improvement in the frequency resolution by about 40 %. The developed method is of great theoretical and practical importance for the further development of the radar theory of high-speed and maneuvering individual and group aerodynamic objects.

Siting strategy for co-locating windfarms and radars considering interference constraints

As the energy sector moves away from use of fossil fuels towards clean renewable energy alternatives, the technical impediment of windfarm interference with radars has dented the deployment of windfarms. This paper provides a step-by-step siting methodology for co-locating windfarms and radars with the support of simulation tools. A procedural framework for co-locating windfarms and radars is suggested. The proposed methodology identifies crucial variables, such as azimuth, frequency, and topographical features affecting the co-existence of radars and windmills. The effect of variables on radar cross-section for feasible radar frequency ranges between 0.1 GHz and 10 GHz is calculated. The siting methodology suggests use of digital terrain maps for evaluating the interference impact due to terrain screening. In case of inextricable circumstances, where radar needs to be sited in high impact zones near windfarms, suitable mitigation techniques are suggested.

A review of modern materials used in military camouflage within the radar frequency range

The article presents an overview of materials which can be employed used to camouflage objects on the modern battlefield in the radar frequency range.

On the Slow-Time k-Space and its Augmentation in Doppler Radar Tomography

Doppler Radar Tomography (DRT) relies on spatial diversity from rotational motion of a target rather than spectral diversity from wide bandwidth signals. The slow-time k-space is a novel form of the spatial frequency space generated by the relative rotational motion of a target at a single radar frequency, which can be exploited for high-resolution target imaging by a narrowband radar with Doppler tomographic signal processing. This paper builds on a previously published work and demonstrates, with real experimental data, a unique and interesting characteristic of the slow-time k-space: it can be augmented and significantly enhance imaging resolution by signal processing. High resolution can reveal finer details in the image, providing more information to identify unknown targets detected by the radar.