In-O Choi

Classification of Targets Improved by Fusion of the Range Profile and the Inverse Synthetic Aperture Radar Image

The range proflle (RP) and the inverse synthetic aperture radar (ISAR) image are the useful radar signatures for classifying unknown targets because they can be used regardless of day- night and weather conditions. Since classiflcation that uses RP and ISAR is heavily dependent on ∞ight conditions, however, much more study is required on this topic. This paper proposes an e-cient method of classifying targets by using a classifler-level fusion of RP and ISAR as well as a scenario-based construction method of the training database. Simulation results using the flve targets composed of point scatterers prove that the proposed method yields high classiflcation results when the targets are ∞ying in a variety of directions at both short and long ranges.

An Efficient Method to Extract the Micro-Motion Parameter of the Missile Using the Time-Frequency Image

It is very difficult to intercept the missiles because of the small radar cross-section and the high maneuverability. In addition, due to the decoy with the similar motion parameters, additional features other than those of the translation motion parameters need to be developed. In this paper, for the successful recognition of missiles, we propose an efficient method to extract micro-motion parameters and scatterers of the missile engaged in the micro motion. The proposed method extracts motion parameters and scatterers by using the matching score between the modeled micro-Doppler function and the time-frequency binary image as a cost function. Simulation results using a target composed of the point scatterer show the parameters and the scatterers were accurately extracted.

Efficient Measurement System to Investigate Micro-Doppler Signature of Ballistic Missile

Micro-Doppler (MD) shift caused by the micro-motion of a ballistic missile (BM) can be very useful to identify it. In this paper, the MD signatures of three scale-model BMs are investigated using a portable measurement system. The measurement system consists of an X-band 2-by-2 phase comparison mono-pulse radar, and a mechanical device that can impart controlled spinning and coning motions simultaneously to a model to yield the MD signature that replicates the characteristic of each target and the corresponding micro-motion. The coning motion determined the overall period of MD, and the spinning motion increased its amplitude. MD was also dependent on aspect angle. The designed system is portable, and can implement many micro-motions; it will contribute to analysis of MD in various situations.

Analysis of Effect of Korean Offshore Wind Farms on Accuracy of X-Band Tracking Radar

Many government-led wind farms are being constructed in Korea as sources of clean and renewable energy. However, construction of these wind farms is continuously opposed by nearby military bases that operate X-band tracking radar because the amplitude and phase of the electromagnetic waves reflected from the wind turbines may interfere with tracking radars installed along the coastline of the Korean peninsula. This paper proposes a method to analyze the effect of a wind farm on tracking radar, and presents the results of using the radar cross section of the blade of a real turbine predicted by the method of physical optics. Simulation results using various flight scenarios demonstrate that the tracking accuracy may be considerably degraded; thus appropriate action is required to eliminate this effect.