• Journal of Institute of Control, Robotics and Systems
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• v.14 no.8
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• pp.740-744
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• 2008

In this paper, we propose a new time-to-go estimation filter for PN guided missiles. The proposed estimator is derived based on the approximation of the length of the PNG homing trajectory that we newly introduced using the special coordinate system. The coordinate system is convenient for taking the target movement into account. In addition, compared with the previous time-to-go estimation techniques, the parameters required for evaluating the length can be obtained only with the seeker measurements. Moreover, the seeker measurement error statistics can effectively be considered since our filter is derived based on the Kalman filter theory. Simulation result for a typical anti-ship see-skimming missile homing trajectory shows the excellent performance of the proposed filter.

• Journal of Agricultural Extension & Community Development
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• v.23 no.1
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• pp.101-114
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• 2016

Local food in rural area as a rural growth tool has to adapt to current market mechanisms by communication and promotion techniques. We need to know what and how local food consumers seek their benefits to market segmentations. The primary purpose of this study was to segment and profile the benefits of local food consumer so as to provide a better understanding of local food in Korea. A self-administered survey was obtained from 448 food consumer in the study area. Three distinct segments were identified based on the benefits; profit seeker (39.7%), passive consumers (19.0%), and value seeker (42.2%), and these were profiled with respect to socio-demographics and local food attitude-related features.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.10
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• pp.2670-2678
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• 1996

Reticle seekers temporally modulate target location onto the incoming spatial signal. When large or multiple targets are present in the FOV, however, it is hard to precisely modulate the incoming target signal by the relicle. To solve this loss of modulatoin depth problem, we present an improved retical seeker using the segmented focal plane array(FPA). The new reticle system uses the normalized difference as well as the modulated signal of each detector output in the segmented FPA. In simulation, we have ascertained the proposed system can make an effective analysis and tracking for multiple or large targets.

• Journal of the Optical Society of Korea
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• v.18 no.1
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• pp.1-8
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• 2014

Spin reticle infrared seekers have good linearity, and the pulse-modulated reticle seekers have good digital characteristics for anti-jamming processing. A basic design for a spin pulse-modulated reticle is introduced. This design uses the rotating design of the optical system in the spin infrared seekers and an improved design of the reticle in the pulse-modulated seekers. The reticle contains a unique well-designed slit to produce one pulse for each target in the spinning period. The target data will be carried by the unique pulse parameters. A simulation tool is implemented using the MATLAB packages for analyzing and evaluating the new design.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.11
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• pp.2730-2741
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• 1993

A mathematical model of the seeker scan-loop which is composed of a spin-stabilized gyroscope and its driving signal processors is derived. The derived model has a transmission zero pair on the imaginary axis near to the required bandwidth. The LQG/LTR design methodology is evolved for the derived scan-loop model. To implement the designed LQG/LTR compensator to the actual plant, the compensator order is reduced using the internally balanced realization method. The performances of the LQG/LTR compensator are tested and compared with those of the P-control. Especially, stability-robustnessexperiments for model uncertainties represented in the form of time-delays are performed. It is demonstrated that the LQG/STR compensator is actually very robust to model uncertainties.

• Journal of the Korea Institute of Military Science and Technology
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• v.8 no.3 s.22
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• pp.56-63
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• 2005

The radome boresight error degrades the microwave seeker ability and the missile guidance performance. It increases the miss distance, also. This paper propose a method of radome boresight error measurement and compensation. The compensation method consist of radome analysis and radome compensation. In the radome analysis stage, we can know that the electromagnetic characteristics distorted by radome. In the compensation stage, the look-up table is built and used for compensation. The test uses a FMS(Flight motion simulator) and adjusts the FMS setup error for more accuracy. The result shows that not using an elaborate radome measurement equipment, the radome boresight error is well compensated easily.

• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.2 s.25
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• pp.87-95
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• 2006

The performance of a microwave missile seeker and radar operating in an air-to-air look-down mode is strongly influenced by the presence of ground clutter In order to correctly account for the effects of ground clutter, it is required to develop a model capable of representing clutter characteristics as a function of range and/or frequency. In this paper, a program to estimate the clutter reflectivity for various ground conditions is developed, using the actually measured data and the data available from open literatures. In addition, clutter characteristics measured for various ground conditions such as sea, agricultural area, urban city and industrial area through the captive flight tests are presented.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.2
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• pp.110-119
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• 1994

The Robust Controller for scan-loop is designed using LQG/LTR Methodology. The design and analysis of spiral, rosette and conical scan patterns are discussed. The perfermance and robustness of the LQG/LTR controller are analyzed through experiments and cpmpared with those of the P-controller. Especially to improve the scan performance at large look angle, the cage coil output is linearized using a binomial equation. It is demonstrated that the scan-loop system by the LQG/LTR control is very robust to phase uncertainties.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.19 no.3
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• pp.289-303
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• 2015

In this paper, an optimal guidance law with terminal angle constraint considering the seeker's lock-on condition, in which the target is located within the field-of-view (FOV) and detection range limits at the end of the midcourse phase, is proposed. The optimal solution is obtained by solving an optimal control problem minimizing the energy cost function weighted by a power of range-to-go subject to the terminal constraints, which can shape the guidance commands and the missile trajectories adjusting guidance gains of the weighting function. The proposed guidance law can be applied to both of the midcourse and terminal phases by setting the desired relative range and look angle to the final interception conditions. The performance of the proposed guidance law is analyzed through nonlinear simulations for various engagement conditions.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.1
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• pp.88-94
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• 2019

A leakage canceller and adaptive algorithm for FMCW Radar is presented. Because a strong leakage signal causes various problems in the transceiver and digital processor, specific FMCW radars are in need of a leakage canceller. The leakage canceller has an adaptive structure and the algorithm calculates the prediction vector and learns the adaptive coefficient simultaneously. The proposed algorithm an improvement of 10 dB in the cancellation performance.