ResearchSpace

Communities in ResearchSpace

Welcome to ResearchSpace, the institutional repository of the CSIR. ResearchSpace is an open access electronic archive collecting, preserving and distributing scholarly digital materials created by the CSIR.

Recent Submissions

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Achieving heterogeneous network microstructure in laser additively manufactured hybrid TiBw/TiC/Ti6Al4V

(2025) Masina, Bathusile N; tshela TH; Lekoadi, Paul M

Laser-directed energy deposition and in-situ alloying processes were used to manufacture hybrid in-situ TiBw/TiC/Ti6Al4V composites while varying the powder flow rate of both TiB2 and TiC. The optical microscopy (OM) and scanning electron microscopy (SEM) reveal that both in-situ TiB-whiskers and TiC particles precipitated at prior β boundaries. This led to the formation of a heterogeneous network and novel network microstructures. It was found that the heterogeneous network microstructure consisted of fine-grain zones with a network structure and coarse-grain zones with spherical structures. The effect of adding TiB2 and TiC on microstructure features and hardness was systemically investigated. It was found that the was no significant increase in the microhardness as the powder flow rate increased of both reinforcements.

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A Study on bistatic RCS simulations, measurements and calibration

(2018) Potgieter, Monique

Bistatic RCS improves detection, characterisation and identification and enhances target information. Its stealthy targets have a low monostatic return and shaping of larger bistatic scattering.

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Bistatic RCS Calculations of Complex Realistic Targets Using Asymptotic Methods

(2018) Potgieter, Monique

Bistatic radar cross section (RCS) can improve target detection and identification due to increased target information. Calculating the bistatic scattering of electrically large targets by using asymptotic computational electromagnetic methods is important as these methods provide a suitable alternative to measurements and full-wave simulations. Measurements and full wave simulations can be impractical due to high cost associated with maintenance of the measurement facilities, long lead times and high computational requirements. The accuracy of physical optics and geometrical optics to calculate the bistatic RCS of two electrically large realistic aircraft targets is investigated in this paper. These two methods are compared to the full-wave multi-level fast multipole method.

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Comparison of the Mutual Information Content between the Monostatic and Bistatic Measured RCS Data of a 1:25 Boeing 707 Model

(2018) Cilliers, JE; Potgieter, M; Blaauw, C; Odendaal, JW; Joubert, J; Woodbridge, K; Baker, C

Many studies have suggested that bistatic radar can improve the classification and recognition of airborne targets due to enhanced target information. This paper makes use of the information theoretic concept of mutual information (MI) and investigates the comparison of the MI content between monostatic and bistatic radar cross section measurements of a 1:25 Boeing 707 scale model. It aims to quantify the increases in the MI content, and hence recognition performance, due to the additional reflected signals available in a bistatic scenario.

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Scatterer extraction and clustering for a DRFM HRR/ISAR resynthesis mode

(2022) Potgieter, Monique; Nel, WAJ

This presentation reports on (amongst others) the challenge of DRFM HRR profile resynthesis, the process to generate discrete scattering points for the DRFM, a SigmaHat overview, scatterer extraction (3D), and various clustering examples and tools.