• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.3
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• pp.186-194
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• 2017

In this paper, we analyze the main performance of satellite's Synthetic Aperture Radar system for high resolution and wide swath. We have used the radiation pattern of reflector antenna with array feed and comparison between the conventional ScanSAR mode and SweepSAR mode has been carried out. The SweepSAR mode is a high-resolution wide-swath mode that transmits beams over a wide range and receives echo signals through sequential beamforming based on SCORE(SCan On REceive). In this paper, we analyzed the operating principle and characteristics of satellite's SweepSAR mode and simulate system performances. In addition, in order to increase the utilization of image, performances analysis for multiple frequency bands(C-band, X-band) has been considered.

• Korean Journal of Remote Sensing
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• v.22 no.6
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• pp.595-600
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• 2006

GOCI is the core paryload of the geostationary satellite COMS(Communication, Ocean and Meteological Satellite) for ocean monitoring. It is scheduled to be launched at the end of 2008. GOCI observes ocean color around the Korean Peninsula over $2500km\times2500km$ area. It used tilted two-axis scan mechanism to observe entire field of view. In this work, the pointing stability of the tilted two-axis method is analyzed and compared with that of gimbal method. The analysis results show that tilted two-axis method gives great stability and it is adequate for geostationary payload. The results can also be used to determine and analyze the mechanism specifications.

• Journal of Satellite, Information and Communications
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• v.7 no.1
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• pp.108-115
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• 2012

Many studies relating the satellite navigation has been done by a relatively small research community in Korea. Most of domestic research has been focused on the application of the satellite navigation technology, but recently the topics of the next generation satellite navigation system are emphasized for its importance. Even opinions suggesting a future Korea's own satellite navigation system are not that uncommon. Due to the geographic, economic, and technological reasons, it is not widely discussed yet. However, a development technical roadmap regarding the Korea's own navigation satellite was established on the Korea Space Development Plan in general term. Currently four global navigation satellite systems are operating or being deployed. Several regional navigation satellite systems are in planning and development phase. Particularly in Asia, China has launched several satellites to complete their own global navigation satellite system, COMPASS until 2020. Japan launched one satellite and has planned to launch rest of set until 2013. It is proper time to develop Korea's own navigation satellite system to acquire the domestic space development technology and the security of navigational infrastructure. In this study, the validity or the feasibility of the Korea's own satellite navigation system is not discussed; rather the possibility and suitability of the additional information to the current operational navigation message is main target. For the first payload of the future Korea's satellite navigation satellite, a regional augmented system is more likely. This study also is focused on that aspect.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.49-53
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• 1994

Advanced Real-Time Satellite Simulator(ARTSS) has been developed to support the telemetry, tracking and command operations of the ETRI satellite control system and to provide satellite engineers a more powerful and informative satellite simulations tool on the desktop. To provide extensive simulation functions for a communication satellite system in the pre-operational and operational missions, ARTSS uses a geosynchronous orbit(GEO) satellite model consisting of the attitude and orbit control subsystem, the power subsystem, the thermal subsystem, the telemetry, command and ranging subsystem, and the communications payload subsystem. In this paper, the system features and functions are presented and the satellite subsystem models are explained in detail.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.448-451
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• 2008

KARI is developing a satellite launch vehicle that is called KSLV(Korea Space Launch Vehicle)-I. During the flight, launch vehicles are exposed to aerodynamic heating conditions while flying at high Mach numbers in the atmosphere. KARI constructed Aerodynamic Thermal Simulation Facility to simulate aerodynamic heating on the ground. ATSF is a facility that can simulate given temperature profile using about 4,000 halogen heaters on fairing model. Aerodynamic heating profile is got from result of thermal analysis using MINIVER, Thermal Desktop, and SINDA/FLUINT. Aerodynamic heating test of fairing of KSLV-I was done using engineering model of payload fairing and Aerodynamic Thermal Simulation Facility. It was found that thermal analytic results show good agreement with aerodynamic heating test results within 6$^{\circ}$C at fairing inner surface. Also it was confirmed that maximum temperature of fairing nose-cone inner surface during flight is lower than allowable temperature limit.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.258-261
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• 2006

The structure of small launch vehicle can be divided into engine section and payload section. This paper introduces modal test of the payload section of small launch vehicle which is composed to satellite, PLA (Payload Adapter), VEB (Vehicle Equipment Bay), KMS (Kick Motor Support) and KM (Kick Motor). From this test, dynamic properties of the 2nd stage structure of small launch vehicle can be obtained. In this test, to simulate free-free boundary condition, test object was hung by 4 bungee cords and excited by using impact hammer Modal test data are analyzed by using TDAS(Test Data Analysis Software). As the result, modal parameters and mode shapes below 100Hz of the 2nd stage of small launch vehicle were identified.

• Journal of Aerospace System Engineering
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• v.3 no.1
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• pp.6-11
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• 2009

It is anticipated that quality assurance for the Ka band Communication Payload System(COPS) development program of the communication, Ocean & Meteorological Satellite(COMS) may be a core technical factor to be concerned in order to avoid any failure, and to assure its final performance during the mission lifetime in space. Those can be managed and verified and assessed by performing the Quality Assurance (QA) and risk management which helps to prevent and to reduce the critical fails. This paper introduces the Product Assurance (PA) system and procedures for controlling and monitoring sub-contractors which were participated in Ka band Communication Payload System (COPS) development. Also this paper shows Quality Assurance (QA) procedures and detailed their processes for assured the product performed by local companies from site survey for selecting companies to delivery of their equipment.

• Journal of Aerospace System Engineering
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• v.2 no.1
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• pp.22-27
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• 2008

It is anticipated that quality assurance for the Ka band Communication Payload System(COPS) development program of the Communication, Ocean & Meteorological Satellite(COMS) may be a core technical factor to be concerned in order to avoid any failure, and to assure its performance during the mission lifetime in space. Those can be managed and verified and assessed by performing the Quality Assurance (QA) and risk management which helps to prevent and reduce the critical fails. This paper introduces the Product Assurance (PA) system and procedures for Ka band Communication Payload System which was established and performed during the Qualification Model (QM) manufacturing phase. In this paper, we present detailed process for the products manufactured by local companies according to PA procedures operated through whole phases from design to test of equipment. Also this paper shows Quality Assurance (QA) procedures and detailed their processes for assured the product quality manufactured by local companies.

• Journal of Satellite, Information and Communications
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• v.2 no.2
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• pp.36-40
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• 2007

EGSE is used to check out satellite payload during the development prior to launch. The EGSE represented in this paper is a test system for Ka band communication transponder of COMS. The EGSE consist of two subsystems as CTS subsystem and PCTS subsystem. Communication Test subsystem (CTS) performs satellite transponder RF performance testing, data analysis and trending. Most of transponder RF performances are automatically tested by the CTS subsystem. Power, Command & Telemetry subsystem (PCTS) monitor telemetry messages from the transponder and send tele-commands to satellite transponder for the configuration change. PCTS also provide simulated S/C power to the transponder during the ground validation testing. The EGSE test functions are verified by the transponder simulator testing and will be used for the flight model transponders testing.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.10
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• pp.97-104
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• 2003

This paper addresses EMC test results for the EQM Communications & Broadcasting Satellite(CBS) Ka-band Payload System. The aim of the EMC test is to verify that the payload system has no effect on the other system and is not affected by the external field. The compliance of EMC system requirements was verified by the analysis and measurement of the emission level from the payload system. The variation of performance by noise injection was measured to inspect the susceptibility of the payload system. The analysis and test results also showed that the electromagnetic interference has no serious effect on the overall payload system performance. It is confirmed that the EQM CBS Ka-band payload system can be operable in the space environment from the EMC performance's viewpoint. It is also obtained that better performance can be acquired by improving waveguide design and integration method.