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Space-Time-Adaptive Processing (STAP) is becoming an integral part of modern airborne and space-based radars for performing Airborne Moving Target Indicator (AMTI) and Ground Moving Target Indicator (GMTI) functions. STAP is an application of optimum and adaptive array processing algorithms to the radar problem of target detection in ground clutter and interference with pulse-Doppler waveforms and...
The paper presents recent progress of the state of the art of space-borne radar technology in case of either earth-orbiting or planetary-orbiting satellites and space probes, respectively. In addition to that recent progress is also discussed concerning specific inversion techniques to evaluate radar measurements, i.e. the art of deriving the relevant physical quantities to be determined such as terrain...
It is natural to approach multi-channel SAR in terms of spatial diversity concepts developed for multiple-input-multiple-output (MIMO) communications and recent advances in MIMO radar. We introduce the MIMO SAR concept in this paper, and the goal here is to research the concept and potential design of a new SAR application based on MIMO theory and techniques. MIMO technology which were develop originally...
Since 1997 the Istituto Nazionale di Geofisica e Vulcanologia (INGV) in Italy has been involved in the development of the airborne RES system named Glacio RADAR, which is continuously upgraded. Radio Echo Sounding (RES) techniques are widely used in glaciological measurements. They are based on the use of radar systems, to obtain information concerning ice thickness of ice sheets and ice shelves,...
Intense RF (radio frequency) interference is the one of the impediments in target detection for high frequency surface wave radar (HFSWR). A novel type of HFSWR, bistatic HF surface wave SIAR (synthesis impulse and aperture radar), has been presented recently. In this paper, the RF interference of this radar is analyzed. Combining with the theoretical analyses and experimental samples, the features...
This paper describes a detection and localization method for high speed moving targets using a short-range ultra-wideband (UWB) impulse radar. Equivalent time sampling impulse radar with an antenna array is used to transmit ultra short-pulse and receive the signal reflected from moving targets. A time domain multi-threshold detection method is proposed to detect the useful weak signal buried in noise...
Airborne radar has evolved from early systems where almost all radar characteristics were fixed to todaypsilas highly flexible, software-driven systems. The most recent advance has been the widespread adoption of active electronically scanned array (AESA) antennas, which has given the system designer unprecedented control of antenna characteristics. However, in common with most conventional radars,...
Helicopters are essential for any mission of humanitarian or assisting nature in disaster areas. Very often they have to cope with missing infrastructure and extreme environmental conditions. Besides darkness and adverse weather, dust and snow are two of the most dangerous conditions for helicopter landing. At the time being, helicopter pilots have no adequate sensors to get information on height...
Planar electromagnetic lenses like the Rotman lens are attractive candidates for beambeam forming networks forming networks because of their high bandwidth of operation and their capability to form multiple beams at lower cost as comparable electronic phase shifting networks. The principles of Rotman lenses have been studied for several decades and examples have been successfully built using different...
A MIMO radar system with M transmitters and N receivers is used for target identification of unknown non-cooperative radar targets. The radar system is assumed wideband with sufficient bandwidth to obtain a target impulse response that shows significant scattering mechanisms and correlates well with the geometry of the target. Contributions in this paper are threefold: First, target identification...
Derived from statistical conditional optimization criteria, the auxiliary-vector (AV) detection algorithm starts from the target vector and adding non-orthogonal auxiliary vector components generates an infinite sequence of tests that converges to the ideal matched filter (MF) processor for any positive definite input autocorrelation matrix. When the input autocorrelation matrix is replaced by a conventional...
Defence Research and Development Canada - Ottawa has developed an experimental airborne radar referred to as the X-band Wideband Experimental Airborne Radar (XWEAR). The radar was designed to support research into SAR imaging of fixed and moving targets (ocean and land), time-frequency analysis of moving targets, clutter suppression for GMTI radar, and ocean surveillance for small and large target...
It is commonplace to use an unweighted transmit aperture and a weighted receive aperture in radars utilising active electronically steered array (AESA) antennas. The preferred receive weightings are usually Gaussian or Taylor as these are perceived to give the best compromise between loss of main-beam directivity, minimised main-beam dilation and excellent sidelobe control. However, this is only part...
Electronically steerable antennas are expensive, whilst mechanically scanned antennas are of complex construction and hence are prone to failure. Based on the leaky-wave frequency-scanning principle, the spinning grating antenna (SGA) provides beam steering without the need of hinges. Whilst pulsed or stepped frequency waveforms may be implemented with this antenna, a frequency modulated continuous...
This paper reports the first results of the in-flight calibration of the COSMO-SkyMed SAR instrument., developed by Thales Alenia Space Italia under contract of Italian Space Agency and Italian Ministry of Defence. Instrument calibration is based on devoted calibration modes for the testing of the antenna on a T/R module basis, and on the development of an antenna model for the prediction of the antenna...
In the frequency modulated continuous wave radar systems, when the transmitter uses periodic linear symmetric triangular wave modulation, the received signal after processed by the mixer will have many harmonics. In the single target detection, this effect can be ignored. However, in the multi-target detection, targets with different ranges and velocities lead to overlapping of the harmonics. Using...
Millimeter-wave band is the general trend for new communication, tracking radar and automotive systems. The crowd of RF frequency bands, the compactness of higher frequency radiating systems and the commercial availability of MMW components drive even more communications, tracking radars and automotive systems toward millimeter-wave band. Moreover, the antenna technology evolves from mechanical to...
Along track SAR interferometry (AT-InSAR) systems use more than one SAR antennas (typically two), mounted on the same platform and displaced along the platform moving direction. They are used to detect ground moving target. The information about the radial velocity of the moving target is estimated from the interferometric phase of the images. In this paper we show that exploiting not only the interferometric...
This paper addresses a new perspective on the exploitation of diversity resembling recent seminal proposals with multiple antennas known as MIMO radar. Our focus pursues similar advantages as spatial MIMO systems but intending to achieve the desired resistance over fading or/and SNR increase without relying on multiple antennas. We design an OFDM-CDM waveform well inspired in modern communications...
In this paper a first iteration X-band T/R module based on a GaN-HEMT MMIC front-end chip-set, comprising a power amplifier, robust low-noise amplifier and power switch will be presented. Even though ultimate T/R module performance cannot be achieved with current GaN-HEMT technological maturity the impact that this technology can have at systems level in terms of performance/cost trade-off will be...
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