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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...
Human motion has complex articulation and flexibility and, thus, is a non-rigid body motion. Radar returns from human with motions are subject to Doppler modulations that provide information about motion dynamics. In this paper, we first discuss radar backscattering from a walking human model and based on the model we derive motion trajectories and velocity patterns of human body parts. Then, we discuss...
Accurate range estimation and tracking of moving targets are important tasks in urban sensing. A dual-frequency radar, which estimate the range of a target based on the phase difference between two closely spaced frequencies, has been shown to be a cost-effective method to accomplish both tasks. When the data is processed using time-frequency analysis, phase difference and Doppler frequency signatures...
This paper illustrates a new algorithm for noncoherent integration and ambiguity resolution in medium PRF wave-forms. Range and Doppler ambiguity resolution is one of the main issues in Medium PRF radars [1,2,3]; it will be shown that the proposed algorithm provides range and Doppler ambiguities resolution as an inherent feature while maximizing detection probability with respect to conventional binary...
A high frequency (HF) radar system comprising a skywave transmit channel and surface wave receive channel is studied. Simple analytic expressions for the resolution of this radar system are determined by considering the spreading of radar signals in Doppler and angle during the ionospheric propagation. The detection of ocean surface targets within the patch of ocean surface illuminated by the radar...
The joint suppression of returns from land and weather clutter is required in many radar applications. Although the optimal method of land-weather clutter suppression is known, the solution is usually not practical to implement. In this paper, we propose a method that employs rank-1 and rank-2 approximations on the weather clutter correlation matrix to obtain suboptimal but simpler detectors which...
The paper presents a method for estimation of acceleration in passive coherent location (PCL) radar. The method is based on the Generalized Chirp Transform, which is a maximum likelihood estimator in this case. The authors propose a fast and efficient algorithm for calculating acceleration by filtering a two-dimensional range-Doppler surface. The algorithm is tested on simulated data as well as on...
In radar imaging, it's well known that relative motion or deformation of parts of illuminated objects induce additional features in the Doppler frequency spectra. These features are called micro-Doppler effect and appear as sidebands around the central Doppler frequency. They can provide valuable information about the structure of the moving parts and may be used for identification purposes. Previous...
A new high resolution Ku-band Doppler radar with scanning capability for meteorological applications has been developed. With the new system design, the radar can accurately measure the radar reflectivity factor with 4-m resolution at the lowest usable height of 60 m from short distance (e.g., minimum detectable reflectivity at 60 m is 5 dBz) to a few km (e.g., min. det. refl. at 2 km is 30 dBz) for...
The capabilities in imaging for forward-looking radar receivers are severely limited so far. This application gap is especially valid for monostatic radars due to their problem producing a significant Doppler shift orthogonal to the direction of illumination. So a two-dimensional resolution of an area of investigation is nearly unattainable. Here bistatic configurations with separated receiver and...
For forward-squint synthetic aperture radar (SAR) imaging, the determination of the Doppler centroid is indispensable. With an analysis of the characteristics of the range cell migration in forward-squint mode, a Doppler centroid estimation technique is proposed, which utilizes the Radon transform to extract the skew angle information from the shape of the target response in the range-compressed image...
Up to now antennas are generally composed of a planar array whose mechanical structure stiffness gives to the radiating elements the needed relative position accuracy to insure a high quality pattern (high gain/ low sidelobes). Operational need evolution and technological breakthroughs will lead to no longer consider antennas as a single well defined unit, but as arrays of antennas whose natural radiating...
Post-Doppler methods are rank reduction techniques to reduce temporal dimensions by applying the Doppler filter and can reduce the processing time than full degrees-of-freedom (DOF) space-time adaptive processing (STAP). In post-Doppler methods, multi-bin post-Doppler methods are generally used to improve the performance of signal-to-interference-plus-noise ratio (SINR). However, it is necessary to...
The relation between main-to-sidelobe ratio and Doppler frequency after pulse compression in pseudorandom code (m-sequence) phase modulation CW radar is studied, and the deduction of its mathematical expression is presented. Since the pulse compression with the non-target range gate in m-sequence phase modulation CW radar is a ldquowide-band input, narrow-band output processrdquo, the sidelobepsilas...
An FPGA-based real-time signal processing unit has been developed to perform Doppler processing in a high resolution CWLFM (continuous wave linear frequency modulated) millimeter-wave radar demonstrator. The article focuses on the strategies followed in order to achieve the required throughput as well as on the measures taken to guarantee coherency. Doppler processing is accomplished to output Range-Doppler...
This paper discusses two adaptive spatial processing approaches that have been recently proposed for mitigating spread-Doppler clutter in skywave over-the-horizon (OTH) radar. The first is slow-time MIMO (SLO-MO) STAP which uses conventional waveforms that are phase-coded so as to be orthogonal after Doppler processing at the receiver, i.e. in ldquoslow-time.rdquo SLO-MO STAP is proposed as a means...
Radar detection of cosmic ray air showers has been discussed for 60 years, but never clearly observed. The topic was reexamined by Gorham in 2001 and some serious simulations were done by Takai, who also initiated the Mariachi project utilizing commercial television transmissions as a signal source. The air showers from ultra-high energy cosmic rays are expected to generate a plasma with plasma frequency...
In the 90s, Galileo Avionica (GA Radar Systems Business Unit) has developed the GRIFO Radar, a multimode-multirole pulse Doppler radar, devoted to occupy an important role in the family of the radar for weapon release. In the last 15 years more than 400 units have been sold to five Air Forces, for more than 100,000 hours of operative flights. The need for the implementation of high-resolution modes,...
A scheme for the real-time estimation and compensation of the moving clutter Doppler shift due to the moving radar platform is presented for the airborne pulsed Doppler radar system. A new scheme employs the dwell-time based clutter-lock MTD method in order to estimate and compensate the mean Doppler shift within antenna beam dwell time by using high speed DSP based Doppler FFT processing. Through...
Tuscany regional government has improved the real time weather monitoring system by setting up a regional weather radar network, to provide an useful hydro-geological risk reduction instrument to the civil protection emergency system. The fully automated regional radar network is constituted by three ARIES-C systems which are fully coherent Doppler weather radars, operating in C-band with very reduced...
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