• 한국항공운항학회:학술대회논문집
• /
• 2004.11a
• /
• pp.253-257
• /
• 2004

• Journal of KIISE:Information Networking
• /
• v.37 no.1
• /
• pp.1-7
• /
• 2010

Network Centric Warfare(NCW) is becoming a prominent concept in the current trend of warfare. To support high quality communication between strategic/tactical units in the concept of NCW, Tactical Airborne Networks are likely to be constructed in the near future to take part in the NCW. In these Tactical Airborne Networks with dynamic topology variations due to very high mobility of participants nodes, more efficient and reliable neighbor discovery protocols are needed. This paper presents the adaptive HELLO message scheduling algorithm for Tactical Airborne Network using directional antennas. The purposed algorithm can reduce the overhead of periodic HELLO message transfer, while guaranteeing successful data transmission. We concluded a mathematical analysis and simulation studies using Qualnet 4.5 for evaluation the performance and efficiency of the proposed scheme.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.67 no.11
• /
• pp.1471-1476
• /
• 2018

In this paper, a high-gain antenna for satellite communication is proposed. The proposed antenna consists of septum polarizer, circular waveguide, Hat-feed structure that has a high-gain and efficiency. Especially, it is smaller and lighter than the conventional satellite communication antennas by applying a hat-feed structure. The measured results show that received gain of proposed antenna is better than 29.9 dBi and transmitted gain of proposed antenna is better than 30.5 dBi. The co-polarized and cross-polarized radiation patterns comply with ITU-RR Ap.8 and ITU-R S.731-1 that are recommended by International Telecommunication Union. The designed high-gain antenna for satellite communication is expected to be used for OTM and airborne satellite systems.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.5 no.3
• /
• pp.98-104
• /
• 2002

An airborne-based Direction-Finding System is developed for the application of ELINT and ES(Electronic Support). The system takes the phase-comparison technology, and has the configuration of multi-based antenna array for the solution of ambiguity due to the increased Direction-Finding resolution. This thesis describes the design of optimized distances among antennas, the electrical characteristics, the method of compensation, the direction-finding accuracy, and et. al. under the condition of the airborne-based environment.

• Journal of Advanced Navigation Technology
• /
• v.10 no.2
• /
• pp.173-180
• /
• 2006

An airborne radar is an essential aviation electronic system of the aircraft to perform various missions in all weather environments. This paper presents the design, development, and test results of the multi-mode pulsed Doppler radar system test model for helicopter-borne flight test. This radar system consists of 4 LRU units, which include ANTU(Antenna Unit), TRU(Tx Rx Unit), RSDU(Radar Signal & Data Processing Unit) and DISU(Display Unit). The developed technologies include the TACCAR processor, planar array antenna, TWTA transmitter, coherent I/Q detector, digital pulse compression, DSP based Doppler FFT filtering, adaptive CFAR, IMU, and tracking capability. The design performance of the developed radar system is verified through various helicopter-borne field tests including MTD (Moving Target Detector) capability for the Doppler compensation due to the moving platform motion.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.20 no.7
• /
• pp.617-624
• /
• 2009

In this paper, an electromagnetic analysis methodology using reaction theorem based on reciprocity theorem is presented for the aspheric ogival radome applied to a missile and/or airborne radar. The presented analysis methodology is verified using actual measured data. The type of antenna assumed to develope the methodology is a waveguide slot array antenna, and has the structure of 2 axes monopulse of "X" type. The shape of radome is assumed as Von Karman and the ratio of length to base diameter(L/D) is assumed to be 2:1. The electrical characteristics of the radome are measured using radome measurement system and the results are compared to the values estimated using the presented analysis methodology. It is found that the comparison shows good agreement. It is expected that the presented methodology can be applied for the development of missile and airborne radome.

• Proceedings of the KSRS Conference
• /
• 2002.10a
• /
• pp.593-597
• /
• 2002

The paper introduces a research on the W-band Millimeter Wave Radiometer(RADW92) through an airborne experiment. Microwave remote sensing images of part of the Yellow River and the WeiHe River are of fared. Analysis of factors influencing the image qualities as well as the resolutions to them are also included. The RADW92 is the first generation of Millimeter Wave Radiometer in China, which works with operating frequency 92 GHz, the bandwidth 2 GHz, the integration time 60ms, the system sensitivity 0.6k and the linearity better than 0.999. Cassegrain Antenna is designed for imaging by conically scanning. The result of the experiment suggested that RADW92 had been adequate for space use.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.11 no.6
• /
• pp.63-73
• /
• 2008

The helicopter position, heading data and the direction finding data of ESM are essentially required to compensate the parallax and analyze the direction finding accuracy of heliborne ESM in flight test phase. In the case of the long test range compared with small platform like as LYNX helicopter and Jisim Island test site, the parallax compensation for direction finding accuracy calculation and GPS position error can be neglected. In this paper, the direction finding accuracy on the basis of helicopter propeller was calculated by coordinate changing between helicopter and transmitting antenna from WGS84 coordinate to navigation coordinate using helicopter position and direction finding data.

• Korean Journal of Remote Sensing
• /
• v.22 no.3
• /
• pp.229-234
• /
• 2006

In tactical theater, it is crucial to detect ground moving targets and to locate them precisely. This problem can be resolved by using SAR (Synthetic Aperture Radar) sensors providing GMTI (Ground Moving Target Indication) capability. In general, to implement a robust GMTI sensor is not simple because of the strong competitions between target signals and clutter signals from the ground, and low speed of moving targets. Contrary to the case that a delay canceller is mostly suitable for ground surveillance radars, DPCA (Displaced Phase Centered Antenna) or STAP (Space Time Adaptive Processing) techniques have been widely adapted for GMTI function of modern airborne radars. In this paper, a new scheme of DPCA using two passive antennas with vertical separation is proposed, which also provides good clutter cancellation performance. The proposed scheme realizes full azimuth coverage for DPCA operation on an airborne platform, which is impossible with classical DPCA configuration. Simulations using various conditions have been performed to validate the proposed scheme, and the results are acceptable.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.21 no.12
• /
• pp.1380-1393
• /
• 2010

This paper presents a design, fabrication and the test results of planar active electronically scanned array(AESA) radar prototype for airborne fighter applications using transmit/receive(T/R) module hybrid technology. LIG Nex1 developed a AESA radar prototype to obtain key technologies for airborne fighter's radar. The AESA radar prototype consists of a radiating array, T/R modules, a RF manifold, distributed power supplies, beam controllers, compact receivers with ADC(Analog-to-Digital Converter), a liquid-cooling unit, and an appropriate structure. The AESA antenna has a 590 mm-diameter, active-element area capable of containing 536 T/R modules. Each module is located to provide a triangle grid with $14.7\;mm{\times}19.5\;mm$ spacing among T/R modules. The array dissipates 1,554 watts, with a DC input of 2,310 watts when operated at the maximum transmit duty factor. The AESA radar prototype was tested on near-field chamber and the results become equal in expected beam pattern, providing the accurate and flexible control of antenna beam steering and beam shaping.