http://hdl.handle.net/10204/908 Sat, 25 May 2013 14:17:52 GMT 2013-05-25T14:17:52Z http://hdl.handle.net/10204/6733 Title: Quality measures for HRR alignment based ISAR imaging algorithms Authors: Janse van Rensburg, V; Mishra, A; Nel, W Abstract: Some Inverse Synthetic Aperture Radar (ISAR) algorithms form the image in a two-step process of range alignment and phase conjugation. This paper discusses a comprehensive set of measures used to quantify the quality of range alignment, with the aim of 1) reviewing their benefits and shortcomings and 2) comparing their relative performance. Some quality measures may favour particular alignment techniques without adequately indicating improved alignment, so using multiple quality measures provide an added means of verifying the alignment quality achieved by any alignment technique. The sensitivity of the quality measures to slight misalignment of profiles and the effects of noise is also investigated. Description: IEEE Radar Conference 2013, Ottawa Canada, 29 April - 3 May 2013 Wed, 01 May 2013 00:00:00 GMT http://hdl.handle.net/10204/6733 2013-05-01T00:00:00Z http://hdl.handle.net/10204/6713 Title: Insights into factors contributing to the observability of a submarine at periscope depth by modern radar, Part 2: EM simulation of mast RCS in a realistic sea surface environment Authors: Smit, JC; Cilliers, JE Abstract: Recently, a set of high resolution radar measurements were undertaken in South Africa to gain insight into factors influencing the detectability of submarine masts deployed under realistic operational conditions. The measurements, processing results and some insights gained are described in. The current paper presents the results of a subsequent computational electromagnetic (CEM) simulation investigation of a simplified mast model in a realistic sea surface environment. The results illustrate some of the effects of the sea surface reflection interaction on the observed RCS of a submarine mast. Description: 2012 IEEE-APS Topical Conference on Antennas and Propagation in Wireless Communications (APWC), Cape Town 2-7 September 2012 Sat, 01 Sep 2012 00:00:00 GMT http://hdl.handle.net/10204/6713 2012-09-01T00:00:00Z http://hdl.handle.net/10204/6625 Title: A method for real-time condition monitoring of haul roads based on Bayesian parameter estimation Authors: Heyns, T; Heyns, PS; De Villiers, JP Abstract: Current haul road management techniques, such as routine, periodic and urgent maintenance have shortcomings in many complex haul road environments. Real-time road condition monitoring may significantly reduce maintenance costs, both to the road and to the vehicles. A recent idea is that vehicle on-board data collection systems could be used to monitor haul roads on a real-time basis by means of vibration signature analysis. This paper proposes a methodology based on Bayesian regression to isolate the effect of varying vehicle speed on the measured vehicle response metric. A key feature of the proposed methodology is that it avoids the costly need to generate analytical or empirical vehicle models. Description: Copyright: 2011 ISTVS. Published by Elsevier. This is the preprint version of the work. The definitive version is published in Journal of Terramechanics, vol. 49(2), pp. 103-113 Sun, 01 Apr 2012 00:00:00 GMT http://hdl.handle.net/10204/6625 2012-04-01T00:00:00Z http://hdl.handle.net/10204/6621 Title: Design of cost effective antennas for instrumentation radars Authors: Botha, L Abstract: The cost of antennas for instrumentation radars are determined by the development cost. By re-use of the reflector system cost effective antennas can be designed. The factors governing the design of such antennas are described here. Description: 2012 IEEE-APS Topical Conference on Antennas and Propagation in Wireless Communications (APWC), Cape Town 2-7 September 2012. Published in IEEE Xplore Sat, 01 Sep 2012 00:00:00 GMT http://hdl.handle.net/10204/6621 2012-09-01T00:00:00Z