• The KIPS Transactions:PartC
• /
• v.8C no.3
• /
• pp.367-372
• /
• 2001

지도제작, 해양생태감시, 기상관측, 및 우주환경감시 등의 분야에 이용되는 저궤도 위성을 관제(위성추적, 원격측정 및 명령)하기 위해 본 논문에서는 최적의 PM 변조지수를 결정하는 방법을 기술하고 수신 데이터의 성능을 평가한다. 이 저궤도 위성인 아리랑 위성은 한국에서는 첫 번째 저궤도 위성이며 1999년 12월 발사되어 현재 임무를 충실히 수행하고 있다. 아리랑 위성 관제시스템의 파라미터에 의해 위성링크를 설계하면, PB 원격측정 신호의 최적 변조지수는 Eb/No마진과 PFD마진의 교차점이 되며 1.92라디안으로 결정된다. 또한 위성의 통과시간에 따라 예측되는 BER은 RT모드에서 최고의 성능을 나타애고, RT+RNG모드에서 최악의 성능을 나타내기 때문에 데이터 전송순서를 위성의 통과시간에 따른 BER 성능 순서인 RT, PB, RT+RNG모드의 순서로 결정함으로써 수신성능을 높일 수 있다.

• Bulletin of the Korean Space Science Society
• /
• 2005.04a
• /
• pp.59-59
• /
• 2005

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2002.10a
• /
• pp.205-208
• /
• 2002

• Proceedings of the Korean Institute of Landscape Architecture Conference
• /
• 2003.03a
• /
• pp.89-92
• /
• 2003

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.12 no.2
• /
• pp.184-192
• /
• 2001

In this paper, we analyze the result of the conduced emission and susceptibility tests performed on the KOMPSAT-I ETB Platform. The ETB platform consists of the EM (Engineering Model) boxes developed to perform the electrical functional test. During the conducted emission test, we measured the instant waveform in time domain when each switch was turn on, and spectrum of the noise in the frequency range of 10 Hz up to100 MHz fur the steady state of the ETB. During the conducted susceptibility test, no malfunction and no serious damage of the electronic box were observed when a simulated noise waveform was applied to the DC power bus. The simulated waveform was obtained by adding the 6 dB-system margin to the worst case waveform measured from the conducted emission. This test was performed as co-development of the KOMPSAT-I with TRW in USA.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.38 no.9
• /
• pp.914-924
• /
• 2010

In this paper, results on the orbit analysis for the KOMPSAT-2 satellite using a real orbit data during the LEOP and normal mission lifetime are presented. In particular, the preparation and performance of an orbit operations during the LEOP is emphasized and the effects of space environments (i.e., Solar activity) on orbit evolutions are investigated comparing to those of the KOMPSAT-1 satellite. The summarized results in this paper would be an important reference to improve the stability and effectiveness of satellite operations during the LEOP and normal mission lifetime in case of LEO satellites such as successors of KOMPSAT-2 (i.e., KOMPSAT-3, KOMPSAT-3A, KOMPSAT-5).

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.32 no.4
• /
• pp.43-52
• /
• 2004

In this paper, the performance of the KOMPSAT-1 orbit determination (OD) accuracy at the ground station was analyzed by using the flight data. The Bayesian least squares estimation was used for the orbit determination and the assessment of the orbit accuracy was evaluated based on orbit overlap comparisons. We also compared the result from OD using GPS navigation solutions with NORAD TLE and the result from OD using range data. Furthermore, the effect of observation type and OBT drift on the accuracy was investigated. As a consequence, It is shown that the OD accuracy using only GPS position data is on the order of 5m RMS (Root Mean Square) with 4 hrs arc overlap for the 30hr arc and the GPS velocity data is not proper as a observation for the OD due to its inferior quality. The significant deterioration of the accuracy due to the critical clock bias was not founded by means of the comparison of OD result from other observations.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.41 no.2
• /
• pp.156-163
• /
• 2013

Collision probability is the most common method to measure the risk of space debris, it is widely used that two dimensional linear collision probability using the closest approach distance. This paper represents the characteristics of object that approach KOMPSAT 2, 3, 5 that have operated or will be operated by Korea. And more precise method than two dimensional linear collision probability, we analyzed the properties of three dimensional nonlinear collision probability using STK/Nonlinear Collision Probability Tool. Through this, efficiency of three dimensional nonlinear collision probability for KOMPSAT series satellites was investigated. The result represents that three dimensional nonlinear collision probability showed the precise outcome at a relative velocity of less than 350m/s. Also, KOMPSAT series satellites appeared to few low relative velocity approaches and showed low efficiency for the three dimensional nonlinear collision probability.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.19 no.4
• /
• pp.373-383
• /
• 2001

This study conducted pilot mapping project to know the possibility of mapping with medium resolution satellite imageries. For this purpose, mapping experiments were conducted with each stereo model imageries of SPOT, KOMPSAT, and IRS- lC. And positional accuracy, analysis of detectable and describable features, and comparison with existing digital map were checked, possible mapping scale and cost analysis were conducted with these results. Regarding SPOT imagery, digital photogrammetric workstation was used for stereoplotting. Regarding KOMPSAT and IRS-lC imageries, because there were data format support problems. head-up digitizing was performed with ortho imageries rectified with DEMs generated by image matching. The results of experiments show that such features as wide road, river, coast line, etc are possible to detect and depict but many other features are not for SPOT, KOMPSAT, and IRS-lC imageries. On the aspect of mapping, therefore, SPOT is available for 1/50,000 topographic map revision, KOMPSAT and IRS-lC for 1/25.000 topographic map revision.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.33 no.7
• /
• pp.92-97
• /
• 2005

In this paper, the performance of the KOMPSAT-1 GPS receiver on orbit was analyzed. OD (Orbit Determination) accuracy using GPS navigation solutions and GPS visibility were investigated with respect to the configuration of the GPS receiver. Indeed, the problem such as ‘3D Fix Loss’ observed during the mission was presented. As a result, the OD accuracy of ‘Best-of-4’ Position Fix Algorithm with 0 degree of mask angle was slightly better than that of ‘N-in-View’ Position Fix Algorithm. On the other hand, the GPS visibility under ‘N-in-View’ Algorithm is better than that of ‘Best-of-4’ Algorithm. The occurrence of temporal 3D Fix Loss is reduced when the ‘N-in-View’ Position Fix Algorithm was selected.