• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.2
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• pp.120-128
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• 2017

The refraction phenomenon of radio waves should be considered to improve the detection accuracy of target altitudes for long-range surveillance radars, however, it is difficult to estimate accurate refractivity of atmosphere for every location. In this paper, we propose the atmosphere evaluation metric(AEM) to estimate atmospheric conditions at target locations using target altitudes obtained from primary surveillance radar(PSR) and secondary surveillance radar(SSR). To verify the suitability of the proposed metric, we observed atmospheric conditions and calculated estimation errors of target altitudes using measured data.

• Journal of Advanced Navigation Technology
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• v.21 no.2
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• pp.179-186
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• 2017

This paper is concerned with an interrogator capable of constructing a interrogation scenario for acquiring active airspace to the intruding aircraft into the surveillance area of the MLAT system. In the MLAT system, the interrogator is an important device used to carry out the interrogation towards the aircraft within the surveillance airspace in the appropriate surveillance scenario. Unlike a conventional SSR's interrogation methods that interrogate for airplanes flying within a certain range, the MLAT system requires a interrogation system that can actively interrogate from remote to near range, or according to operational scenarios, for aircraft intruding into the surveillance range. The interrogator implemented in this paper can be used for interrogating and monitoring aircraft within each surveillance airspace using whisper-shout algorithm according to varying output power based on the actual operation distance.

• Journal of Advanced Navigation Technology
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• v.12 no.6
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• pp.539-547
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• 2008

In this paper, preliminary results for design of prototype ADS-ADS-B/TIS-B Validation Testbed (AVT) are described. Automatic Dependent Surveillance (ADS-B) is a novel surveillance concept using the Global Navigation Satellite System (GNSS) and a digital datalink. Air traffic information from ADS-B non-equipped aircraft is not acquired since ADS-B is a dependent surveillance. Traffic Information Service-Broadcast (TIS-B) provides surveillance data from Secondary surveillance Radar (SSR) for ADS-B non-equipped aircraft. AVT is based on ADS-B and TIS-B as an integrated platform for air traffic surveillance system for CNS/ATM.

• Journal of Advanced Navigation Technology
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• v.17 no.1
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• pp.1-8
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• 2013

In the next generation of ATM, ADS-B(Automatic Dependent Surveillance-Broadcast) and multilateration are the main technology recommended by ICAO(International Civil Aviation Organization). However, there are a lot of non-equipped ADS-B aircraft today. Therefore, TIS-B(Traffic Information Service-Broadcast) provides traffic information, which has obtained from radars for non-equipped ADS-B aircraft. In this paper, we presented an onboard multilateration system for non-equipped ADS-B aircraft using SSR(Secondary Surveillance Radar) signal instead of TIS-B. TIS-B has a lot of error because of using radar data, but multilateration has less error than radar because of using TDOA(Time Difference of Arrival) method. Results of performance analysis show that the position accuracy is improved by the proposed method using on-board multilateration.

• Journal of Advanced Navigation Technology
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• v.19 no.6
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• pp.515-523
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• 2015

The air traffic control service in the domestic airports and approach control centers is provided using data from flight plan and a variety of surveillance sensors such as SSR, ADS-B and MLAT, etc. The physical connection methods and data types of the sensors are various, as so using these data directly may cause a lot of cost in development and maintenance of air traffic control equipment. As a method for solving such a problem, we propose a system that can convert the data from the heterogeneous sensors to the unified format which can be processed by the air traffic control devices. In this paper, the analysis results for the physical characteristics and data formats of the typical surveillance sensors are described. Also, the system design and the system implementation result for the multi-sensor interface system to interoperate the sensors are explained in detail.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.7
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• pp.720-728
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• 2011

In this paper, development of the monopulse secondary surveillance radar antenna which can be used for IFF system is presented. This antenna that is passive linear array is comprised of the row-feeder and several array-elements. The row-feeder provides sum, different and SLS(Sidelobe Supression) channels which are optimized the distribution of the power and phase ratio. The azimuthe sidelobe level of the sum channel beam pattern is -20 dBc or less. The SLS channel covers the sidelobe of the sum-chanel in the whole azimuth angle range. And the difference channel is used to perform the mono-pulse function, improves the detection accuracy in the azimuth direction. Meanwhile, the arrayelement makes shaped beam in the elevation angle, in order to eliminate the clutter and multipath effects from the ground. Performance of the antenna developed is verified by the measurement of S-parameters and far-field beam pattern, and satisfies all of the development specifications well.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2000.05a
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• pp.59-64
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• 2000

Active radar reflector may be less familiar, since their uses have been limited to military applications, especially the enhancement of the effective radar cross-sections of missile test range in the drone aircraft and missiles. Perhaps the most widely-blown applications of radar transponders are Identification Friend or Foe(IFF) and its civilian counterpart, secondary surveilliance radar for Air Traffic Control(ATC), and most recently, as Search And Rescue Transponder(SART) in the Global Maritime Distress and Safety System(GMDSS). Since it happens frequently accidents on the sea, the problems of the contamination more seriously considered. The conventional navigation buoy and utilities are not sufficient to maintain the safety of the sea and thus new structured concept must be considered. Therefore, this paper propose and implement the active radar reflector with a enhanced structure. The results are shown that the performance of the system is significantly improved comparing with the conventional utilities.

• Journal of Korea Society of Industrial Information Systems
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• v.5 no.3
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• pp.38-43
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• 2000

Active radar reflector may be less familiar, since their uses have been limited to military applications, especially the enhancement of the effective radar cross-sections of missile test range in the drone aircraft and missiles. Perhaps the most widely-Down applications of radar transponders are Identification Friend or Foe(IFF) and its civilian counterpart secondary surveilliance radar for Air Traffic Control(ATC), and most recently, as Search And Rescue Transponder(SART) in the Global Maritime Distress and Safety System(GMDSS). Since it happens frequently accidents on the sea, the problems of the contamination more seriously considered. The conventional navigation buoy and utilities are not sufficient to maintain the safety of the sea and thus new structured concept must be considered. Therefore, this paper propose and implement the active radar reflector with a enhanced function. The results are shown that the performance of the system is significantly improved comparing with the conventional utilities.

• Journal of Advanced Navigation Technology
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• v.21 no.2
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• pp.163-170
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• 2017

MLAT which is an independent cooperative surveillance system is applied to increase the positon resoultin of secondary survelliance radar. MLAT uses the hyperboic or hyperboloid position mesurement algorithm. Central processing unit of MLAT calculates target position using time difference of arrival (TDOA) which can be solved from time of arrival (TOA) information of each receivers (at least 4 receivers). To increase position resolution of MLAT which use TDOA, TOA which is transfer time from tranmitter to receiver shold be calculated with precision time resolution in receiver. This paper explained the MLAT system briefly and explained ATD which is one of means of calcuating pulse position. ATD is applied to solve the deviation of pulse position due to different amplitude of signals in mulitiple receivers. In this paper, to analysis the performance of ATD, the simulation result of LAS and CDS was compared with the simulation result of basic threshold method.

• The Korean Journal of Air & Space Law and Policy
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• v.28 no.2
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• pp.117-144
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• 2013

The MOLIT is also establishing the flight safety standards for UAV within the current Aviation Law. Accordingly the required flight criteria includes operator location, mission operation limit, equipment, etc. which are the principle and standard applied based on the airspace use for UAV. Also, general flight rules, visual flight rules, instrument flight rules are required to be applied to the actual flight. Besides, an appliance regulation needs to be arranged regarding two-way communication, ATC and communication issue, airspace and area in-flight between UAS(Unmanned Aircraft System) users. An operation of the UAV in the air significantly requires the guarantee of the aircraft's capacity, and also the standardized flight criteria. A safe and smooth use is ensured only if this criteria is applied and understood by the entire airspace users. For the purpose, a standardized military UAV flight operations criteria and a law complementary scheme.