[1] Techniques that use only measurements provided by millimeter-wavelength Doppler radar for retrieving the properties of clouds provide certain practical advantages over techniques that require measurements from multiple instruments. We concentrate on the capacity of the moments of the Doppler spectrum to provide information suitable for retrieving the microphysical properties of cirrus cloud...

This paper proposes a time-frequency algorithm based on short-time fractional order Fourier transformation (STFRFT) for identification of a complicated movement targets. This algorithm, consisting of a STFRFT order-changing and quick selection method, is effective in reducing the computation load. A multi-order STFRFT time-frequency algorithm is also developed that makes use of the time-frequen...

Vertically pointing Doppler radar has been used to study the evolution of 4 ice particles as they sediment through a cirrus cloud. The measured Doppler 5 fall speeds, together with radar-derived estimates for the altitude of cloud 6 top, are used to estimate a characteristic fall time t c for the 'average' ice par-7 ticle. The change in radar reflectivity Z is studied as a function of t c , and...

The accurate detection of targets is a significant problem in multiple-input multiple-output (MIMO) radar. Recent advances of Compressive Sensing offer a means of efficiently accomplishing this task. The sparsity constraints needed to apply the techniques of Compressive Sensing to problems in radar systems have led to discretizations of the target scene in various domains, such as azimuth, time...

HF skywave ‘over-the-horizon’ radars experience exceptionally high levels of clutter from the earth’s surface as a consequence of their ‘look-down’ propagation geometry. While Doppler processing is effective in separating aircraft echoes from the clutter, thereby enabling detection, the same does not always hold for slow moving targets. In particular, ship echoes occupy the same region of Doppl...

[1] This study examines a hurricane prediction system that uses an ensemble Kalman filter (EnKF) to assimilate high‐ resolution airborne radar observations for convection‐ permitting hurricane initialization and forecasting. This system demonstrated very promising performance, especially on hurricane intensity forecasts, through experiments over all 61 applicable NOAA P‐3 airborne Doppler missi...

Recent studies have focused on developing security systems using micro-Doppler radars to detect human bodies. However, the resolution of these conventional methods is unsuitable for identifying bodies and moreover, most of these conventional methods were designed for a solitary or sufficiently well-spaced targets. This paper proposes a solution to these problems with an image separation method ...

In this paper, we describe how an active radar/sonar imaging problem may be formulated as a virtual passive sensor array processing problem. We consider an active sensing problem where it is desired to form a range-Doppler image at a slowtime rate, even though the radar/sonar can transmit pulses at a fast time rate. By transmitting pulses at the fast time rate we can estimate the second-order s...