Radar: Reflections and speculations

Abstract

Two outstanding speakers will open the third and fourth day of the conference with one hour plenary talks. This talk will try to briefly review what developments have had an impact on radar (that is, what concepts and technology have made radar of value in the past), what radar concepts and technology were important in the past but might not be so important in the future, what things appear to be of current interest in radar but are not as likely to see lasting utility (that is, ideas that one should examine with caution when exploring potential new directions in radar), and a few new directions in radar that might be of interest to pursue. Among the new directions that might be briefly discussed include: phased arrays that perform multiple function simultaneously rather than in sequence, a different look at the cause of microwave sea echo, and living with a crowded microwave spectrum by use of shared spectrum.

Experimental photonic generation of chirped pulses using nonlinear dispersion-based incoherent processing

“…More specifically, one of these interesting signals is the chirped microwave pulse with the main characteristic of having a frequency variation along the time duration pulse, which involves a large bandwidth signal processing. Among the diverse applications where chirped microwave pulses are used, spread spectrum communications, pulsed compression radars or tomography for medical imaging [9][10][11] can be highlighted.…”

“…Introducing an optical spectral shaping and wavelength-to-time mapping using spatially chirped fiber Bragg grating [16], a Sagnac-loop mirror incorporating a chirped fiber Bragg grating [17] or an interferometric structure incorporating an optically-pumped linearly chirped fiber Bragg grating [18], the TBWP can be increased up to 23, 40 and 45, respectively. All previous schemes are based on a coherent technique with a limiting flexibility to reconfigure the output waveform which is determining for applications such as radar pulse compression [10]. In order to overcome this lack of flexibility, we recently proposed a photonic scheme which theoretically permits to increase the chirped waveform flexibility compared with coherent techniques by means of incoherent processing using a nonlinear dispersive element [19].…”

Efficient exhaustive search for binary complementary code sets

“…It is often the case that a weak signal needs to be detected despite the presence of noise and other interference. In such situations, a matched filter is called upon, because of its well-known ability to maximize signal-to-noise ratio [1] [6]. For a signal pulse with binary phase coding, the response can be studied as the aperiodic autocorrelation of the binary code.…”

“…The best achievable with a binary codes is an autocorrelation with a sharp central peak and remaining elements, or "sidelobes", having peak size 1; the codes that achieve this are the wellknown Barker codes [1] [6]. However, odd-length Barker codes exist only up to length 13 [12], and for even-length Barkers, only up to length 4, if the well-known "Barker Conjecture" holds true [13].…”

A Study on the Methods to Simulate the Target Reflective Signal in a Wideband Radar

“…DRFM은 주로 전자 전을 목적으로 개발되어 그 구현 방법 및 성능에 관한 연 구들이 이루어져 왔으며 [5]～ [7] , 최근에는 레이더의 표적 반사 신호 모의를 위해서도 많이 활용되고 있다 [8], [9] . [11] .…”