• Journal of Advanced Navigation Technology
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• v.12 no.1
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• pp.1-7
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• 2008

International Civil Aviation Organization(ICAO) adopted VOR(Very high frequency Omni-Range) as an international standard air navigation system in 1949 and recommended every country to make use of it in formulating air route and guiding take-off and landing of an aircraft. VOR is quite a useful navigation system so that more than 2,000 VORs have been installed all over the world including 39 in Korea: however, VOR signal could be easily affected by its circumstance like a mountainous area because it provides navigation information through AM and FM of VHF carrier. Therefore this study intends to investigate how much VOR performance is affected by its circumstances. For this purpose, the performance of the 10 VORs influenced by 24 obstacles are measured and analyzed by using an aircraft equipped with measuring instruments. This study may give us a feasible solution of problems related to the VOR siting in the future.

• Journal of Advanced Navigation Technology
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• v.8 no.2
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• pp.144-154
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• 2004

In this paper we apply the space-time block codes (STBCs), the key technologies for the 4th generation mobile communication systems, to the OFDM system and analyze their performances. First, we derive the signal models for representative STBC schemes and demodulation procedures for each scheme. We also select the parameters for OFDM system considering mobile cellular environments and assign adequate modulation schemes to STBC-OFDM schemes according to the transmission rate from 2bps/Hz to 4bps/Hz. We finally compare and analyze the performances of STBC-OFDM schemes for the selected transmission rates through computer simulations, together with performance comparison when the same modulation scheme being adopted.

• Transactions on Control, Automation and Systems Engineering
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• v.4 no.2
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• pp.114-123
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• 2002

Called VISTA (Variable-stability In-flight Simulator Test Aircraft), the one-of-a-kind NF-l6D has a simulation system that can mimic several aircraft. Though housed in an F-l6 Fighting Falcon airframe, VISTA can also act like the F-15 Eagle or the Navy's F-14 Tomcat. More importantly, such flexibility allows for improved training and consolidation of some sorties. Consequently USAF Test Pilot School students will have an opportunity to learn how to test future integrated cockpits. In this paper we will use the multiple model adaptive estimation (MMAE) and the multiple model adaptive controller (MMAC) techniques to model the aircraft's flight control system containing the longitudinal and lateral-directional axes. Single and dual actuator and sensor failures will also be included in the simulation. White Gaussian noise will be included to simulate the effects of atmospheric disturbances.

• Journal of Positioning, Navigation, and Timing
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• v.9 no.2
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• pp.125-129
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• 2020

In this paper, Zero velocity UPdaTe (ZUPT) is implemented on the navigation system of Remotely Piloted Aircraft for GNSS denied environment. RPA's navigation system suffers from lack or loss of satellite signal while maintenance or ground test inside a hangar. Although some of the hangars install GPS repeaters for indoor tests, the anti-jamming equipment with array antenna blocks the repeater signal regarding them as hostile jamming signal. With ZUPT, an aircraft navigation system can be tested free from the divergence of navigation solution without line-of-sight satellites. The designed ZUPT aided centralized Kalman Filter is implemented on the Embedded GPS&INS and simulated with Captive Flight Test data. The simulation result shows stable navigation solution without GNSS updates.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2000.04a
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• pp.6-6
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• 2000

On-orbit thermal behavior of KOMPSAT (Korea Multi-purpose Satellite) propulsion system employing hydrazine (N$_2$H$_4$) liquid monopropellant is addressed. Thermal control performance to prevent propellant freezing in spacecraft-operational orbit was verified by flight telemetry data obtained during LEOP (Launch and Early Operation Phase). Results are depicted in terms of temperature history during several orbits selected and are compared with acceptable temperature ranges of system components. Cyclic behavior of temperature is reduced into duty cycles of the avionics heaters and subsequently converted into the electrical power required to keep away from propellant freezing. Temperature of each component which was achieved under on-ground thermal-balanced condition of spacecraft, is presented for comparison with the flight data, additionally.

• Journal of Advanced Navigation Technology
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• v.16 no.3
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• pp.449-454
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• 2012

According to the development of the ubiquitous computing technic today, the sensor base system is becoming a big issue in IT fields. This study is to develop a smart weather watching system which allows us to carry out temperature measuring without regard to location and altitude using the sensor devices. this system is composed of the wireless receiver module(PC base) and the wireless measuring module(ATmega2560 base).

• Journal of the Korean Society of Systems Engineering
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• v.2 no.1
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• pp.18-23
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• 2006

The purpose of this study and report is to provide, to the MND, an independent cost analysis of modernizing software of F-16 fighter fleets to support the use of several weapon system options, including JDAM, AIM-9X and HARM Targeting System etc. The study analyzed each options with software sizing, software cost, enabling hardware cost, flight test cost, system engineering cost, and 3 strategies. And the study proposed and analyzed some alternative strategies: strategy1 is to modernize software only within existing electronic processing capability; strategy2 is a full upgrade of weapons avionics with plug compatible electronics; strategy3 is an approach defined to mirror the USAF Common Configuration Implementation Approach (CCIP). The recommended alternative is strategy2.

• Journal of Information Processing Systems
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• v.15 no.6
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• pp.1462-1471
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• 2019

Real-time embedded systems have become pervasive in general industry. They also began to be applied in such domains as avionics, automotive, aerospace, healthcare, and industrial Internet. However, the system failure of such domains could result in catastrophic consequences. Runtime software testing is required in such domains that demands very high accuracy. Traditional runtime software testing based on handwork is very inefficient and time consuming. Hence, test automation methodologies in runtime is demanding. In this paper, we introduce a software testing system that translates a real-time software into a monitorable real-time software. The monitorable real-time software means the software provides the monitoring information in runtime. The monitoring target are time constraints of the input real-time software. We anticipate that our system lessens the burden of runtime software testing.

• International Journal of Aerospace System Engineering
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• v.2 no.2
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• pp.87-91
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• 2015

KT-1P for the Peru Air Force will be used as a utility aircraft with upgraded avionics equipment and arming capability based on KT-1 and KA-1. KT-1P should be shown for compatibility of new store loading configurations loaded with dispenser, bomb, and rocket based on aircraft-store compatibility test and evaluation procedures before KT-1P is operated as a light attack aircraft. The weapon system ground test for installation and flight test for envelope expansion including store separation are described in this paper, which was performed referring 'seek eagle program' under MIL-HDBK-1763 and MIL-HDBK-244A.

• Journal of the Korea Institute of Military Science and Technology
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• v.5 no.2
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• pp.123-131
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• 2002

ASC(Avionics System Computer) was developed to control weapon delivery and navigation sensors, and to perform man-machine interface with pilots for XKO-1 aircraft. The data communications between ASC and UFC(Up Front Controller), DC(Data Concentrator) were implemented by RS422 serial data bus. Also, SCIL(Standard Computer Interface Library) was designed to facilitate control and management of the computer hardware resources and is embedded in the ASC. These structures have a merit of noise immunity and a reduction of wire harness for signal lines, and enable OFP(Operational Flight Program) programmers to use the SCIL easily without knowing hardware details. Manufactured system was on installed on XKO-1, and peformed for BIT(Built In Test) and interface test with UFC and DC. The test results show that it meets the system requirements.