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New infrared counter-countermeasure technique using an iterative self-organizing data analysis algorithm for the rosette scanning infrared seeker

Hyun-Ki HongChung-Ang UniversityGraduate School of Advanced ImagingScience, Multimedia, and FilmDepartment of Image EngineeringImage and Information Laboratory221 Heuksuk-Dong, DongJak-KuSeoul 156-756, South KoreaE-mail: jsk@candy.ee.cau.ac.krDong-Sun SeoMyong-Ji UniversityDepartment of Electronic EngineeringYonginKyonggido 449-728, South KoreaJong-Soo Choi,

Novel adaptive digital signal processing algorithm for a stationary reticle seeker

Conventional stationary reticle seeker uses an analog signal processing technology to extract a target position in the field of view. The analog technology is optimized for only frequency modulation signals, which makes it difficult to use various and adaptive signal processing, and causes the performance limit of the conventional technology. We propose a novel adaptive digital signal processing algorithm to overcome the performance limit. The proposed algorithm classifies the modulation signals into the FM and FM/AM signals and applies a different signal processing algorithm, which is optimized for the modulation characteristics of each signal. The algorithm also employs an adaptive clipping level to minimize the noise effect. Our simulation results show that the proposed algorithm is superior to the conventional one in terms of the linearity of the static gain curve, tracking performance, and robustness against noise.

Adaptive infrared counter-countermeasure for two-color spinning concentric-annular-ring reticle seeker

This paper presents a dynamic simulation loop that gives tracking results for a two-color concentric annular ring (CAR) reticle seeker. Our simulation tool includes a target flare model and a propor- tional navigation guidance loop. The CAR reticle systems performance and the flare effects are analyzed in various scenarios. When a flare is present in the field of view, the simulation results show that the reticle seeker cannot maintain precise target tracking. We propose a two-color countercountermeasure using the least-mean-square method to cope with a presence of infrared (IR) flares. The proposed method makes use of simultaneous processing of the modulation output in two IR wave- length bands. One is the midwave IR (a primary input signal), and the other is the shortwave IR (a reference input signal). Simulation results have shown that our adaptive algorithm can achieve effective cancella- tion of flare signals with high intensity.

Target position extraction based on instantaneous frequency estimation in a fixed-reticle seeker

To extract a precise target position in the presence of infrared countermeasures and significant noise, we propose a new algorithm based on the instantaneous frequency (IF) estimation of the sinusoidal frequency modulation (SFM) signals for a fixed-reticle seeker. To esti- mate the IF for target position extraction, the proposed algorithm maps the multicomponent SFM signal into the time-frequency plane to exam- ine its time-frequency distribution, and then applies the Hough transform. The simulation results show that the proposed algorithm can extract the target position efficiently in the presence of flare countermeasures and noise.

New counter-countermeasure algorithm for two-color infrared seekers

A counter-countermeasures (CCM) algorithm in a target tracking system is required for efficient target tracking under countermeasures (CM) such as infrared flares. Most of the CCM algorithms employ some forms of spectral band discrimination to distinguish between a target and CM. We adopt two detection bands based on the spectral distribution characteristics (SDC) of a target and flares and define the energy ratio between the two band signals (MNR) to represent their SDC and to distinguish them. The proposed algorithm computes the MNR of the incident band signals and its histogram, detects the MNR of flare signal from the histogram, and extracts target signal only from the target and flare mixed signal. To estimate the performance of the proposed algorithm, we simulate it under various conditions. The simulation results show that the proposed algorithm can eliminate the effect of CM well.

Eminent scene change detection algorithm and new indexing method for video retrieval on MPEG sequences

We propose an eminent scene change detection (SCD) algorithm, and also present a new video-indexing method for fast content- based browsing and retrieval in video databases. The first step in our approach is to extract representative frames by using the proposed SCD algorithm from the Motion Picture Experts Group (MPEG) video sequence. Thereafter, we perform the video indexing by applying the rosette pattern (RP) to the extracted representative frames, and retrieve them. A principal cause of these processing procedures is that the performance of video indexing and retrieval system depends on the SCD. And how accurately SCD performs as well as a preprocessing are some of the considerations that we must take into account. Therefore, we classify every possible scene change that may happen within the video into three types: abrupt, gradual, and flashlight. And we detect every kind of scene change. Our SCD algorithm is better than the conventional ones in terms of SCD performance and we demonstrate its superiority by experiments. We also extract representative frames that represent series of detected scenes by the proposed accumulative histogram intersection measure (AHIM). Finally, we apply the RP to extracted representative frames for indexing, we can remarkably reduce the number of pixels (NOP) required to index and excellently retrieve the video scene.

IR Model of 3D Aircraft for Simulation of Reticle Seekers

This paper presents an efficient simulation method that generates thermal images and also gives tracking results of infra-red (IR) reticle seekers. First, we make an IR model of the object with the internal heat source, and generate thermal images by the optical system of the reticle seeker and the atmospheric turbulence. Using the obtained thermal images, we can simulate IR reticle seekers in various scenarios including countermeasures (CM) such as flares. Simulation results show that we can generate more accurate images by using the proposed method, which is applicable to the study of the development of counter-countermeasures (CCMs).

Scene change detection for video retrieval on MPEG streams

IN this paper, we propose a new scene change detection (SCD) algorithm, and also provide a novel video-indexing scheme for fast content-based browsing and retrieval in video databases. We detect scene changes from the MPEG video sequence, and extract key frames to represent contents of a shot. Then, we perform the video indexing by applying the rosette pattern to the extracted key frames, and retrieve them. Our SCD method is better than the conventional ones in terms of the SCD performance. Moreover, by applying the rosette pattern for indexing, we can remarkably reduce the number of pixels required to index and excellently retrieve the video scene.

Simulation target detection at UV and IR bands

Air-to-Air Homing Missile has widely adopted infrared seeker, which makes use of thermal energy emitted from the target to detect it exactly. The target is equipped with countermeasure (CM) such as flare to protect itself from homing missile. The purpose of this paper is to develop counter-countermeasure (CCM) to cope with the CM operated by the target. Not only the radiant features of the target but also that of the flare at ultraviolet band have been compared and analyzed to select the band that can effectively remove the effects of the flare. We use a reference level for removal of the noise effects and the background. The simulation results show that our CCM algorithm can detect precisely the target location in spite of the presence of the flare.

3D simulator for the rosette-scanning seeker using thresholding techniques

The IR seeker is a device that detects heats radiated from a target and provides the target position with servo system of the missile. Among various kinds of seekers, the rosette- scanning seeker ins a tracker in which a single IR detector scans the total field of view (TFOV) in a rosette pattern, and then produces 2D image about a target. Since the detected image has various shapes according to the target position in the TFOV, it is necessary that we investigate the tracking algorithm applicable to the different shapes. In this paper, we present a comparative study of the projective and the moment technique among the various target tracking techniques. Using the 3 degree-of-freedom simulator, we evaluate two algorithms and confirm the better performance of the moment technique as a tracking one.