12-04-2014, 04:29 PM
NOISE RADAR
[attachment=61237]
ABSTRACT
The word “Radar “is an acronym derived from the words Radio Detection And Ranging. It refers to the technique of using radio waves to detect the presence of objects in the atmosphere. Radar was designed shortly before World War II. Its primary purpose was to detect the presence of aircraft. Researches are being carried out on various types of radars. Recently, there has been considerable interest in noise radar over a wide spectrum of applications, such as through wall surveillance, detection, tracking, Doppler estimation, polarimetry, interferometry, ground-penetrating or subsurface profiling, synthetic aperture radar (SAR) imaging, inverse synthetic aperture radar (ISAR) imaging, foliage penetration imaging, etc. Noise radar is a form of random signal radar whose transmitting signal is a microwave noise source or is modulated by a lower frequency white noise source in contrast to the conventional pulse, CW (continuous wave), FM (frequency modulated), or FM/CW radars. Because of the truly random transmitting signal, noise radars have many advantages compared with conventional radars, including unambiguous measurement of range and Doppler estimations, high immunity to noise, very low probability of intercept (LPI), high electro-magnetic compatibility, good electronic counter countermeasure (ECCM) capability, good counter electronic support measure (CESM) capability, and ideal ’thumbtack’ ambiguity function. In a variety of noisy environments, the noise radar always has a much lower LPI than the conventional LFM radar. Noise radars, because of the random nature of the waveforms, are very good at suppressing very high level interference from other radars compared to LFM radars.
[attachment=61237]
ABSTRACT
The word “Radar “is an acronym derived from the words Radio Detection And Ranging. It refers to the technique of using radio waves to detect the presence of objects in the atmosphere. Radar was designed shortly before World War II. Its primary purpose was to detect the presence of aircraft. Researches are being carried out on various types of radars. Recently, there has been considerable interest in noise radar over a wide spectrum of applications, such as through wall surveillance, detection, tracking, Doppler estimation, polarimetry, interferometry, ground-penetrating or subsurface profiling, synthetic aperture radar (SAR) imaging, inverse synthetic aperture radar (ISAR) imaging, foliage penetration imaging, etc. Noise radar is a form of random signal radar whose transmitting signal is a microwave noise source or is modulated by a lower frequency white noise source in contrast to the conventional pulse, CW (continuous wave), FM (frequency modulated), or FM/CW radars. Because of the truly random transmitting signal, noise radars have many advantages compared with conventional radars, including unambiguous measurement of range and Doppler estimations, high immunity to noise, very low probability of intercept (LPI), high electro-magnetic compatibility, good electronic counter countermeasure (ECCM) capability, good counter electronic support measure (CESM) capability, and ideal ’thumbtack’ ambiguity function. In a variety of noisy environments, the noise radar always has a much lower LPI than the conventional LFM radar. Noise radars, because of the random nature of the waveforms, are very good at suppressing very high level interference from other radars compared to LFM radars.