• Journal of Astronomy and Space Sciences
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• v.23 no.4
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• pp.415-424
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• 2006

In this paper, requirements of Meteorological Administration about Meteorological Image. (MI) of Communications, Ocean and Meteorological Satellite (COMS) is analyzed for the design of COMS ground station and according to the analysis results, the distribution image size of each observation area suitable for satellite Field Of View (FOV) stated at the requirements of meteorological administration is determined and the precise satellite FOV and the size of distribution image is calculated on the basis of the image size of the determined observation area. The results in this paper were applied to the detailed design for COMS ground station and also are expected to be used for the future observation scheduling and the scheduling of distribution of user data.

• Bulletin of the Korean Space Science Society
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• 1992.10a
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• pp.12-12
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• 1992

Results from the Earth Radiation Budget Experiment (ERBE) will help interpret the data from the operational satellite system. However, a major problem exists because a follow-on experiment to ERBE is not planned until the late 1990`s. Meanwhile, it will be necessary to provide OLR estimates from the operational satellite system. Since 1973the outgoing long wave radiation(OLR) data have been obtained by the 10#m window radiance(AVHRR) estimation technique from he observation NOAA operational satellites. However, those data have not been universall if accepted because they are estimated from the radiance in but one narrow spectral regiou. However , this type of technique has not been exploited for use with data from the ]fIRS multispectral radiometer. Since the radiance data measured by HIRS contains more: information on atmospheric variables than the AVHRR, it is a potentially better instrument for operational estimates of the OLR In this study, results from model are better flux estimates than the AVHRR, The technique is then tested by comparing simultalleous AVHRR and HIRS OLR estimations with a radiation model flux calculation froml homogeneous atmospheric scenes at the regions of desert and subtropic ocean.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.3
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• pp.493-507
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• 2018

Due to high spatio-temporal variability of amount and optical/microphysical properties of atmospheric aerosols, satellite-based observations have been demanded for spatiotemporal monitoring the major aerosols. Observations of the heavy aerosol episodes and determination on the dominant aerosol types from a geostationary satellite can provide a chance to prepare in advance for harmful aerosol episodes as it can repeatedly monitor the temporal evolution. A new geostationary observation sensor, namely the Advanced Himawari Imager (AHI), onboard the Himawari-8 platform, has been observing high spatial and temporal images at sixteen wavelengths from 2016. Using observed spectral visible reflectance and infrared brightness temperature (BT), the algorithm to find major aerosol type such as volcanic ash (VA), desert dust (DD), polluted aerosol (PA), and clean aerosol (CA), was developed. RGB color composite image shows dusty, hazy, and cloudy area then it can be applied for comparing aerosol detection product (ADP). The CALIPSO level 2 vertical feature mask (VFM) data and MODIS level 2 aerosol product are used to be compared with the Himawari-8/AHI ADP. The VFM products can deliver nearly coincident dataset, but not many match-ups can be returned due to presence of clouds and very narrow swath. From the case study, the percent correct (PC) values acquired from this comparisons are 0.76 for DD, 0.99 for PA, 0.87 for CA, respectively. The MODIS L2 Aerosol products can deliver nearly coincident dataset with many collocated locations over ocean and land. Increased accuracy values were acquired in Asian region as POD=0.96 over land and 0.69 over ocean, which were comparable to full disc region as POD=0.93 over land and 0.48 over ocean. The Himawari-8/AHI ADP algorithm is going to be improved continuously as well as the validation efforts will be processed by comparing the larger number of collocation data with another satellite or ground based observation data.

• Atmosphere
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• v.28 no.2
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• pp.201-209
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• 2018

Benefits of the next generation geostationary meteorological satellite observation (e.g., GEO-KOMPSAT-2A) are qualitatively and comprehensively described and discussed. Main beneficial phenomena for application can be listed as tropical cyclones (typhoon), high impact weather (heavy rainfall, lightning, and hail), ocean, air pollution (particulate matter), forest fire, fog, aircraft icing, volcanic eruption, and space weather. The next generation satellites with highly enhanced spatial and temporal resolution images, expanding channels, and basic and additional products are expected to create the new valuable benefits, including the contribution to the reduction of socioeconomic losses due to weather-related disasters. In particular, the new satellite observations are readily applicable to early warning and very-short time forecast application of hazardous weather phenomena, global climate change monitoring and adaptation, improvement of numerical weather forecast skill, and technical improvement of space weather monitoring and forecast. Several policy plans for expanding the application of the next generation satellite data are suggested.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.2
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• pp.1-10
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• 2009

Recently the large scale of forest disaster such as landslide and forest fire gives a very bad impact on not only forest ecosystem but also farm business so that it has became the main issue of environmental problems. In this study, the landslide hazard area forecast method was developed by considering not only the topographic thematic maps based on GIS and satellite images but also amount of rainfall data, which are very important factors of landslide. Uljin-gun was selected as the study area and the GIS weight score and overlay analysis were applied to topographical map and meteorological observation map. Finally the landslide area distribution map was constructed by considering the evaluation criteria. Also, the accuracy could be acquired by comparing the landslide hazard area forecast map and real damaged area extracted from satellite image.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.282-285
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• 2007

Satellite observed brightness temperature simulation using a radiative transfer model (here after, RTM) is useful for various fields, for example sensor design and channel selection by using theoretically calculated radiance data, development of satellite data processing algorithm and algorithm parameter determination before launch. This study is focused on elaborating the simulation procedure, and analyzing of difference between observed and modelled clear sky brightness temperatures. For the CMDPS (COMS Meteorological Data Processing System) development, the simulated clear sky brightness temperatures are used to determine whether the corresponding pixels are cloud-contaminated in cloud mask algorithm as a reference data. Also it provides important information for calibrating satellite observed radiances. Meanwhile, simulated brightness temperatures of COMS channels plan to be used for assessing the CMDPS performance test. For these applications, the RTM requires fast calculation and high accuracy. The simulated clear sky brightness temperatures are compared with those of MTSAT-1R observation to assess the model performance and the quality of the observation. The results show that there is good agreement in the ocean mostly, while in the land disagreement is partially found due to surface characteristics such as land surface temperature, surface vegetation, terrain effect, and so on.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.8A
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• pp.1149-1155
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• 1999

LEO(Low altitude Earth Orbit) Satellite systems have been utilized in the field of earth and scientific observation (cartography mission, ocean color monitoring, bioglogical coeanography, space environments observation by space physics sensor, and meteorological observation, atmospheric observation etc.), and the field of military (military communications and secret information, enemy reconnaissance etc.), and recently been developing in the field of mobile satellite commnication of GMPCS for commercial utilization. In Korea, KOMPSAT I satellite and ground system are been developing and planed to be lunched on October 1999 In this paper, the link budge of the TT&C system for LEO satellite is described and the relations between elevation angle and pass time of LEO satellite are calculated according to satellite moving. And the packet error rates of receiving data are derived three packet error rates(PER) of real-time(RT) mode, playback(PB) mode, and real-time and range tone(RT+RNG) mode are estimated according to pass time of satellite. The results of PER are the best at real-time and the worst at real-time mode and range mode at the all pass time of satellite. The average error free packet(EFP)s of real-time mode, playback mode, and real-time and range tone for the pass time of satellite are obtained as 99.999999%, 99.999912%, 99.995945% respectively. Therefore, transmission sequence of telemetry data are determined such as PER sequence according to pass time, namely, real-time, playback, and real-time and range mode.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.821-826
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• 2002

The KOMPSAT-2 DCSU(the data compression & storage unit) performs the acquisition of image data from cameras, the compression with requested compression rate, the storage with specified file ID on the mission command and the distribution to the assigned DLS(Data Link System) channels per the mission and operation requirements. The worldwide observation using the MSC is able to be achieved by this DCSU's behavior. This paper presents the features of KOMPSAT-2 DCSU and provides proper ground operation concept after launch.

• Journal of Astronomy and Space Sciences
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• v.38 no.1
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• pp.45-53
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• 2021

GLONASS, a satellite navigation system developed in Russia since 1976, is defunct and orbits in an unstable attitude. The satellites in these problems are not managed and there is no precise information, which can increase the risk of collisions with other space objects. In this study, detailed attitude dynamic have to be analyzed through photometry data, which requires spin period and spin axis. The light curve data is obtained by observing through the photometer at the Graz station and the power spectrum is calculated to obtain the cycle of the satellite. The geometric relationship between observer and sun is analyzed for GLONASS-50 satellite. The box-wing model is applied to obtain the phase reflection of the satellite and obtain the Irradiation of the satellite through this information. In Light Curve and Irradiation, the spin axis is calculated for each peak points with the distance square minimum technique. The spin axis of the GLONASS-50 satellite is RA = 116°, Dec = 92°.

• Journal of Space Technology and Applications
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• v.4 no.2
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• pp.169-183
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• 2024

Korea Astronomy and Space Science Institute (KASI) developed the Geochang satellite laser ranging (SLR) system for the scientific research on the space geodesy as well as for the national space missions including precise orbit determination and space surveillance. The operation system was developed based on the server-client communication structure, which controls the SLR subsystems, provides manual and automatic observation modes based on the observation algorithm, generates the range data between satellites and SLR stations, and carry out the post-processing to remove noises. In this study, we analyzed the requirements of operation system, and presented the development environments, the software structure and the observation algorithm, for the server-client communications. We also obtained laser ranging data for the ground target and the space geodetic satellite, and then analyzed the ranging precision between the Geochang SLR station and the International Laser Ranging Service (ILRS) network stations, in order to verify the operation system.