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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Astronomy and Space Sciences
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Journal DOI :
The Korean Space Science Society
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Volume & Issues
Volume 19, Issue 4 - Dec 2002
Volume 19, Issue 3 - Sep 2002
Volume 19, Issue 2 - Jun 2002
Volume 19, Issue 1 - Mar 2002
Selecting the target year
UNCERTAINTIES INVOLVED IN THE IONOSPHERIC CONDUCTIVITY ESTIMATION
Journal of Astronomy and Space Sciences, volume 19, issue 4, 2002, Pages 243~254
DOI : 10.5140/JASS.2002.19.4.243
Various uncertainties involved in ionospheric conductivity estimation utilizing the electron density profile obtained from the Sondrestrom incoherent scatter radar are examined. First, we compare the conductivity which is based on raw electron density and the one based on corrected electron density that takes into account the effects of the difference between the electron and ion temperatures and the Debye length. The corrected electron density yields higher Pedersen and Hall conductivities than the raw electron density does. Second, the dependence of collision frequency model on the conductivity estimation is examined. Below 110 km conductivity does not depend significantly on collision frequency models. Above 110 km, however, the collision models affect the conductivity estimation. Third, the influence of the electron and ion temperatures on the conductivity estimation is examined. Electron and ion temperatures carrying an error of about 10% do not seem to affect significantly the conductivity estimation. Fourth, also examined is the effect of the choice of the altitude range of integration in calculating the height-integrated conductivity, conductance. It has been demonstrated that the lower and upper boundaries of the integration are quite sensitive to the estimation of the Hall and Pedersen conductances, respectively.
A STUDY OF ISO SPECTRA FOR HERBIG Ae/Be STARS
Suh, Kyung-Won ; Kim, Mi-Ryang ; Baek, Ji-Hye ;
Journal of Astronomy and Space Sciences, volume 19, issue 4, 2002, Pages 255~262
DOI : 10.5140/JASS.2002.19.4.255
We present the infrared spectra of Herbig Ae/Be stars including the Infrared Space Ob-servatory (ISO) data. To investigate the overall properties of their circumstellar dust envelope and/or disk, we combine the IR spectra with photometric data ranging from the UV through the optical into the sub-mm region. We study the general characteristics of the spectral energy distributions using simple analysis. We plot the positions on the HR-diagram to compare with the theoretical pre-main-sequence evolution tracks.
LIGHT CURVE ANALYSIS OF CONTACT BINARY SYSTEM V523 CASSIOPEIAE
Journal of Astronomy and Space Sciences, volume 19, issue 4, 2002, Pages 263~272
DOI : 10.5140/JASS.2002.19.4.263
A total of 616 observations (308 in B, 308 in V) to. V523 Cas was made on three nights from October 19 to 21 in 1999 using the 1.8m telescope with 2K CCD camera of the Bohyunsan Optical Astronomy Observatory of KAO. With our data we constructed the BV light curves and determined 4 times of minimum light. We also obtained physical parameters of the system by combined analysis of both light and radial velocity curves using the Wilson-Devinney code.
PERFORMANCE OF FIMS MICROCHANNEL PLATE DETECTOR SYSTEM
Journal of Astronomy and Space Sciences, volume 19, issue 4, 2002, Pages 273~282
DOI : 10.5140/JASS.2002.19.4.273
We describe some performance of the detector electronics system for the FIMS (Far-ultraviolet Imaging Spectrograph) mission. The FIMS mission to map the far ultraviolet sky uses MCP (micro-channel plate) detectors with a crossed delay line anode to record photon arrival events. FIMS has two MCP detectors, each with a ~25mm
25mm active area. The unconventional anode design allows for the use of a single set of position encoding electronics for both detector fields. The centroid position of the charge cloud, generated by the photon-stimulated MCP, is determined by measuring the arrival times at both ends of the anode following amplification and external delay. The temporal response of the detector electronics system determines the readout's positional resolution for the charge centroid. High temporal resolution (<
ps FWHM) and low power consumption (< 6W) were achieved for the FIMS detector electronics system.
THERMAL ANALYSIS OF FIMS TDC AND LVPS ELECTRONIC BOARDS
Journal of Astronomy and Space Sciences, volume 19, issue 4, 2002, Pages 283~292
DOI : 10.5140/JASS.2002.19.4.283
Electronic boards of Far-ultraviolet IMaging Spectrograph (FIMS) should be designed to maintain their performances, and their temperatures should be remained within the allowed temperatures in operational environments. Thermal analysis at the electronic board level has been performed, and it is confirmed the electronics parts could be kept within their allowed temperature ranges.
DEVELOPMENT OF MAGNETOMETER DIGITAL CIRCUIT FOR KSR-3 ROCKET AND ANALYTICAL STUDY ON CALIBRATION RESULT
Journal of Astronomy and Space Sciences, volume 19, issue 4, 2002, Pages 293~304
DOI : 10.5140/JASS.2002.19.4.293
This paper describes the re-design and the calibration results of the MAG digital circuit onboard the KSR-3. We enhanced the sampling rate of magnetometer data. Also, we reduced noise and increased authoritativeness of data. We could confirm that AIM resolution was decreased less than InT of analog calibration by a digital calibration of magnetometer. Therefore, we used numerical-program to correct this problem. As a result, we could calculate correction and error of data. These corrections will be applied to magnetometer data after the launch of KSR-3.
PRODUCT10N OF KSR-III AIRGLOW PHOTOMETERS TO MEASURE MUV AIRGLOWS OF THE UPPER ATMOSPHERE ABOVE THE KOREAN PENINSULAR
Journal of Astronomy and Space Sciences, volume 19, issue 4, 2002, Pages 305~318
DOI : 10.5140/JASS.2002.19.4.305
We have constructed two flight models of airglow photometer system (AGP) to be onboard Korea Sounding Rocket-III (KSR-III) for detection of MUV dayglow above the Korean peninsular. The AGP system is designed to detect dayglow emissions of OI 2972
and background 3070
toward the horizon at altitudes between 100 km and 300 km. The AGP system consists of a photometer body, a baffle an electronic control unit and a battery unit. The MUV dayglow emissions enter through a narrow band interference filter and focusing lens of the photometer, which contains an ultraviolet sensitive photomultiplier tube. The photometer is equipped with an in-flight calibration light source on a circular plane that will rotate at the rocket's apogee. A bane tube is installed at the entry of the photometer in order to block strong scattering lights from the lower atmosphere. We have carried out laboratory measurements of sensitivity and in-flight calibration light source for the AGP flight models. Although absolute sensitivities of the AGP flight models could not be determined in the country, relative sensitivities among channels are well measured so that observation data during rocket flight in the future can be analyzed with confidence.
MEASUREMENTS OF ALBEDO AND SPECTRAL PATTERNS OF MAN-MADE SATELLITE MATERIALS
Journal of Astronomy and Space Sciences, volume 19, issue 4, 2002, Pages 319~326
DOI : 10.5140/JASS.2002.19.4.319
Laboratory tests have been carried out for investigation of the spectroscopic characteristics at visible wavelength of 12 common satellite materials used in satellite bus and payload. The obtained spectral data show that the materials can be classified and identified since their spectral features and albedos distinctly differ among them. It is suggested that the result of the laboratory tests for the satellite materials can be used for the predictions of material types, material composition ratios, sizes, and masses in comparison with the spectral data obtained from observations of new satellites or space debris.
A DESIGN STUDY OF THB 400MHZ WIDE-BAND DIGITAL AUTOCORRELATION SPECTROMETER
Journal of Astronomy and Space Sciences, volume 19, issue 4, 2002, Pages 327~340
DOI : 10.5140/JASS.2002.19.4.327
In this paper, we performed the design study of a wide-band digital autocorrelation spectrometer for the observation study of an extra-galaxy's spectral lines and the survey research of the special radio sources in field of the radio astronomy observational research. The autocorrelation spectrometer designed in this paper can be used to their spectrometer of any system because this spectrometer has a wide dynamic power and frequency range properties. In this system we use the aliasing sampling method to minimize the band loss. For the output signal of the correlator we can increase the signal processing speed using by a special DSP chip, the integration and the FFT using hardware, so this spectrometer can support the newest developed technique for the radio astronomy observation so called “On the fly” method.
DOME ENCLOSURE: CLAM SHELL DESIGN
Journal of Astronomy and Space Sciences, volume 19, issue 4, 2002, Pages 341~350
DOI : 10.5140/JASS.2002.19.4.341
Near Earth Object Patrol Team (National Research Lab.) at KAO and YSTAR team at Yonsei University Observatory jointly developed a dome enclosure to be installed abroad together with a survey telescope. It has a fully-open clam shell type design to maximize the fast slew capability of the telescope and is also sturdy enough to protect the observation system under extreme weather conditions. We also developed an electric control circuit for the enclosure so that it can become a part of automated observing system. The enclosure has been installed at the Sutherland Observatory of South African Astronomical Observatory in April 2002, and has been successfully operational.
THE DESIGN OF DGPS/INS INTEGRATION FOR IMPLEMENTATION OF 4S-Van
Journal of Astronomy and Space Sciences, volume 19, issue 4, 2002, Pages 351~366
DOI : 10.5140/JASS.2002.19.4.351
In this study, we developed low cost INS and (D)GPS integration for continuous attitude and position and utilized it for the determination of exterior orientation parameters of image sensors which are equipped in 4S-Van. During initial alignment process, the heading information was extracted from twin GPS and fine alignment with Kalman filter was performed for the determination of roll and pitch. Simulation and van test were performed for the performance analysis. Based on simulation result, roll and pitch error is around 0.01-0.03 degrees and yaw error around 0.1 degrees. Based on van test, position error in linear road is around 10 cm and curve around 1 m. Using direct georeferencing method, the image sensor's orientation and position information can be acquired directly from (D)GPS/INS integration. 4S-Van achieved 3D spatial data using (D)GPS/INS and image data can be applied to the spatial data integration and application such as contemporary digital map update, road facility management and Video GIS DB.
EVALUATION OF DATA QUALITY OF PERMANENT GPS STATIONS IN SOUTH KOREA
Park, Kwan-Dong ; Kim, Ki-Nam ; Lim, Hyung-Chul ; Park, Pil-Ho ;
Journal of Astronomy and Space Sciences, volume 19, issue 4, 2002, Pages 367~376
DOI : 10.5140/JASS.2002.19.4.367
As of September 2002, there are more than 60 operational permanent Global Positioning System (GPS) stations in South Korea. Their data are being used for a variety of purposes: geodynamics, geodesy, real-time navigation, atmospheric science, and geography. Especially, many of the sites are reference stations for DGPS (Differential GPS). However, there has been no comprehensive and qualitative analysis published to evaluate the data quality. In this study, we present preliminary results of our assessment of the permanent GPS sites in South Korea. We have analyzed the multi-path characteristics of each station using a quality-checking software package called TEQC. Another multipath analysis tool based on post-fit phase residuals was used to check the repeating patterns and the amount of the multipath at each site. The long-term stability of each station was analyzed using the root-mean-square (RMS) error of the estimated site positions for one year, which enabled us to evaluate the mount stability. In addition, the number of cycle slips at each site was derived by TEQC. Based on these series of tests, we compared the stability and data quality of permanent GPS stations in South Korea.
DEVELOPMENT OF REAL-TIME PRECISE POSITIONING ALGORITHM USING GPS L1 CARRIER PHASE DATA
Journal of Astronomy and Space Sciences, volume 19, issue 4, 2002, Pages 377~384
DOI : 10.5140/JASS.2002.19.4.377
We have developed Real-time Phase DAta processor(RPDAP) for GPS L1 carrie. And also, we tested the RPDAP's positioning accuracy compared with results of real time kinematic(RTK) positioning. While quality of the conventional L1 RTK positioning highly depend on receiving condition, the RPDAP can gives more stable positioning result because of different set of common GPS satellites, which searched by elevation mask angle and signal strength. In this paper, we demonstrated characteristics of the RPDAP compared with the L1 RTK technique. And we discussed several improvement ways to apply the RPDAP to precise real-time positioning using low-cost GPS receiver. With correcting the discussed weak points in new future, the RPDAP will be used in the field of precise real-time application, such as precise car navigation and precise personal location services.
PRECISE OR81T DETERMINATION OF GPS-36 SATELLITE USING SATELLITE LASER RANGING
Journal of Astronomy and Space Sciences, volume 19, issue 4, 2002, Pages 385~394
DOI : 10.5140/JASS.2002.19.4.385
Satellite laser ranging is a technique for precisely measuring the range between a laser station and a satellite that is equipped with retro-reflectors. SLR technique was first used for Beacon-B satellite in 1964 with the ranging accuracy of meter level. Now the single shot have centimeter level accuracy and the normal point have mm level in ranging. In this study we developed the algorithm for precise orbit determination using SLR data and performed the orbit determination of GPS-36 satellite using the algorithm. RMS of the estimated orbit was 74cm when compared with IGS precise orbit. It is known that RMS of SLR measurement residual is below 55mm. But we were able to achieve 44mm RMS of residual throughout this study.
NORAD TLE CONVERSION FROM OSCULATING ORBITAL ELEMENT
Lee, Byoung-Sun ;
Journal of Astronomy and Space Sciences, volume 19, issue 4, 2002, Pages 395~402
DOI : 10.5140/JASS.2002.19.4.395
The NORAD type Two Line Element (TLE) was obtained from the osculating orbital elements by an iterative approximation procedure. The mathematical model was presented and computer program was developed for the conversion. The osculating orbital elements of the KOMPSAT-1 were converted into the NORAD TLE. Then the effect of the SGP4 atmospheric drag coefficient (
) was analyzed by comparison of the orbit propagation results with different
3D DISPLAY OF SPACECRAFT DYNAMICS USING REAL TELEMETRY
Lee, Sang-Uk ; Cho, Sung-Ki ; Kim, Jae-Hoon ;
Journal of Astronomy and Space Sciences, volume 19, issue 4, 2002, Pages 403~408
DOI : 10.5140/JASS.2002.19.4.403
3D display of spacecraft motion by using telemetry data received from satellite in real-time is described. Telemetry data are converted to the appropriate form for 3-D display by the real-time preprocessor. Stored playback telemetry data also can be processed for the display. 3D display of spacecraft motion by using real telemetry data provides intuitive comprehension of spacecraft dynamics.