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The detection performance of high frequency over-the-horizon radar (HF OTHR) systems is heavily influenced by the presence of radar clutter that originates by Bragg backscatter from plasma structures in the aurora zone, denoted as auroral clutter. The work in [1] developed a data model for the clutter seen by HF OTHR system. The model uses a geometric optics approach to determine the power spectral...
A novel method for along-track motion parameter estimation of moving targets is presented in this paper. The along-track velocity causes moving targets smeared in SAR images, hence it is in great need to estimate the along-track velocity of moving targets. In this paper, a method known as Coherent Map-Drift (CMD) is adopted to estimate the velocity of moving targets. By using this approach, the along-track...
The ground moving targets identification (GMTI) is one of the most important applications for SAR, the performance of the GMTI system can be analyzed and evaluated by modeling the whole system through simulation method. The raw signal generation in the time domain by the target-by-target method achieves a realistic simulation but not efficient. As for the issue, the accurate 2-D spectrum for moving...
A set of radar trials, looking at advanced multifunction radar (MFR) technology, were undertaken, in a United Kingdom (UK) and United States (US) collaboration, at Wallops Island, Virginia, USA, throughout the year 2010. During the trials, a wealth of high quality radar and meteorological data were recorded under a wide range of clutter, weather and propagation conditions. A small selection of this...
This article presents a new antenna for radar applications. It is composed by a Joint Ultra Low-Profile EBG antennas (or pixels) which form a 1D Matrix. The advantage of this solution is the fact that each pixel is isolated to the neighboring ones by metallic walls which make them independent of each other and reduce the coupling levels. With this design it is possible to cover a zone with a constant...
The target tracking problem becomes more realistic when factors as time varying target number, measurements immersed in clutter and/or false alarms are introduced in the problem modeling. The Random Finite Sets theory provides an appropriate framework to deal with multiple targets in a dynamic scenario for the mathematical modeling and stochastic filtering. This paper analyzes the tracking problem...
Tracking performance can be considerably improved if amplitude information (AI) is used, since AI helps to obtain more accurate target and clutter likelihoods. The Probability Hypothesis Density (PHD) filter using AI has been studied in Raleigh distributed clutter. However, Raleigh distribution is not suitable when describing the heavy-tailed clutters observed by high resolution radar or when grazing...
Degeneration of inverse synthetic aperture radar (ISAR) image quality may be caused by rotational motion induced quadratic phase error (QPE). Traditional algorithms can't correct the QPE well with smaller number of pulses. In this paper, the Parametric Compressed Sensing Least Square (PCS-LS) is proposed to compensate the QPE on each range bin and to reconstruct the image robustly. Mig-25 data is...
HF Skywave radars rely on the refractive properties of the ionosphere to reach distances beyond the horizon. The instability of this medium on wide temporal and spatial scales is one of the most important issue to be addressed in the design of such systems, especially when considering a MIMO (Multiple Input Multiple Output) configuration. In such a configuration, multiple transmitters emit orthogonal...
This paper examines the detection of weak moving targets using long-dwell, multi-channel radar. The impact of unknown target motion on detection performance is addressed. Signal-to-noise ratio (SNR) loss caused by mismatch between the matched filter and the actual target phase history - as might occur when using conventional space-time adaptive processing (STAP) - is quantified, and major factors...
The Mars Science Laboratory's rover named Curiosity successfully landed on Mars on August 6, 2012. One component of the Mars Science Laboratory (MSL) Entry, Descent, and Landing (EDL) system was the Terminal Descent Sensor (TDS) landing radar. In this paper we describe laboratory testing of this radar performed before launch.
High-accuracy localization remains a much desired but elusive feature for passive radio transponders as used in radio-frequency identification (RFID). We believe that the principle of cognitive radar can overcome the fundamental physical limitations hindering its implementation. We propose to jointly employ a narrowband radio to interrogate the transponders and an adaptive (ultra) wideband backscatter...
A new and robust sparse SAR image reconstruction technique is proposed for off-grid targets in the CS framework. In the proposed approach, basis vectors corresponding to on-grid point reflectors are perturbed on a finer grid to find the appropriate bases for the reconstruction of off-grid targets. To provide efficiency of the reconstruction, the EMMP algorithm is applied to find reflectivity center...
Using a colocated Multiple Input Multiple Output (MIMO) radar system, we consider the problem of joint design of amplitudes and frequency-hopping codes for frequency-hopping waveforms. First, we present the MIMO radar signal model and the sparse representation. Then, we formulate a novel game model and propose two joint design algorithms, one applying a non-cooperative scheme, and the other applying...
Increasingly stringent spectral spreading constraints are motivating a paradigm shift in the spectrum engineering of radar systems. Future spectrum requirements will likely dictate narrower spectral masks that will change based on geography. The desire to operate radar systems efficiently with waveforms that will provide desired detection capabilities must mesh with the need to meet spectral mask...
This paper focuses on the azimuth variant bistatic synthetic apeture radar (SAR) data processing in a spaceborne/airborne hybrid bistatic configuration. Due to the extreme differences in platform velocities and slant ranges, Spaceborne/Airborne Hybrid Bistatic SAR (SAH-BiSAR) data are more challenging to process than the translational invariant Bistatic counterparts because serious two-dimensional...
When multiple flying vehicles with bearing-only tracking collaborate in locating a target, observation data fusion is required to compensate the drift of navigation system, the noise from observation system, and the unknown maneuvering of target object. Kalman Filtering of nonlinear observation data needs a huge amount of computation, and will cause trouble to onboard embedded computing systems. Least...
The orthogonal frequency division multiplexing (OFDM) MIMO SAR is the combination of sub-aperture technique and sub-band technique to achieve high azimuth resolution, high range resolution, and wide swath simultaneously. However, the interference of the sub-bands and the channel errors (channel mismatches), like constant phase error, amplitude error, and sampling delay error of the fast time, have...
In comparison with airborne SAR, Near-Space SAR can provide much larger and long term coverage of the interested ground scene. Moreover, Near-Space SAR owns shorter revisit period and better motor ability than space-borne case. In fact, Near-Space SAR is potential to provide robust survivability, high resolution, wide swath and high revisiting frequency that we have desperately wanted. Current researches...
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