• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.5
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• pp.532-541
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• 2014

The ship-borne mobile down range telemetry antenna system having 4.6 m reflector antenna and 3-axis mounting structure at S-band requires the precise pointing accuracy at sea for the launch mission. Using the LEO satellites tracking, a method to determine and verify the antenna pointing and tracking performance, and to find the pointing bias which dominantly contributes to the pointing inaccuracy, is presented. Based upon the tests conducted on the Jeju sea and Pacific sea, the pointing bias is determined and its origin is also identified as the drift of the heading angle of the gyrocompass. The applied systematic correction taking into account the pointing bias, and the achieved improvement of the pointing accuracy are shown. Thanks to the correction, it is presented that this antenna tracked the launcher(KSLV-I) stably within the required pointing accuracy in the following KSLV-I third launch.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.1
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• pp.93-100
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• 2012

A telemetry signal occurs the line-of-sight problem by the effect of geography in flight test. A fixed relay system or a mobile relay system is used to solve that problem in general but we propose an airborne telemetry relay system using aircraft in this paper. An airborne telemetry relay system receives the telemetry signal of the test vehicle and then retransmits it to the ground system. The receiving antenna which is a phased array antenna can be tilted to ${\pm}30^{\circ}$ beam direction by beam-forming and track the rapidly moving test vehicle in effect. The relay pod which is mounted to an aircraft consists of the front antenna and the side antenna. It receives S-band signal and then down-converts the frequency to L-band signal. As a result, that can remove the frequency interference on an aircraft while retransmitting.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.12
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• pp.1359-1369
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• 2007

This paper describes the technique of satellite direction finding and main beam steering of the adaptive array antenna system which is used for mobile TT&C(Tracking Telemetry&Command) system. To be able to control the satellite on mobile vehicle while moving, the relative directional information of the satellite to the mobile vehicle is necessary to make main beam to the direction of satellite. To do this MUSIC, which is one of the super-resolution algorithm of wave direction finding, is used and then the performance analysis and quantization problem of phase shifter are addressed. This paper is valuable in the respect of showing feasibility of designing the moble TT&C using adative array antenna system.