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This research substantially improved the differentiation of rice of two geographical origins utilizing a wide area illumination (WAI) scheme capable of collecting Raman spectra of a large sample area (28.3 mm2) synchronously without sample rotation. For the purposes of comparison, we also employed a conventional scheme in which the laser illuminated only small areas. Principal component analysis (PCA) was used to differentiate the two geographical origins using the Raman spectra collected through both the conventional and the WAI schemes. The WAI scheme exhibited improved differentiation, primarily due to the fact that the WAI scheme could efficiently produce Raman spectra with a more reliable sample representation, as well as better reproducibility. The spectral feature obtained using the conventional scheme appeared to be more variable; however, this variation resulted more from unsuccessful sample representation than from an actual change in the sample composition. We conclude that the WAI scheme has a good potential for the analysis of diverse agricultural samples that consist of solid granules. Copyright © 2008 John Wiley & Sons, Ltd.

Today Global Navigation Satellite Systems (GNSS) are widely used for determining position. Within the city environment, however, in which there are many tall buildings, GNSS signals are frequently interrupted, making it difficult for users to obtain information on their exact position. This paper analyzed the availability and positioning performance of a GPS augmented system within the Seoul urban area using the Japanese QZSS (Quasi-Zenith Satellite System) and a geostationary satellite. A 3-dimensional reproduction of Seoul that was based on the 3D GIS (Geographic Information System) Digital Map and a satellite tracking algorithm using Ray-Triangle Intersection algorithm were discussed. A satellite tracking algorithm was verified through filed testing and the QZSS orbit simulator was realized using Keplerian parameter. DOP (Dilution of Precision) and availability in the urban area of Seoul were analyzed using a GPS/QZSS/geostationary satellite separately and simultaneously.

The GNSS receivers suffer from the multipath interference which is highly correlated with the line of sight (LoS) signal. Such interference results in tracking and ranging errors. In this paper, we propose a novel algorithm that can estimate the direction of arrival (DoA) of the LoS signal in the presence of highly correlated multipath interference. The proposed algorithm combines the matching pursuits algorithm for multipath estimation and the minimum norm algorithm for DoA estimation. An efficient combination of two algorithms yields reliable estimates of the DoA of LoS signal as demonstrated by computer simulations.

This paper analyzes the availability and Dilution Of Precision (DOP) of GPS, widely used in positioning, with and without augmentation using QZSS (Quasi-Zenith Satellite System). Orbit simulator for QZSS is developed using Kepler‘s orbital parameters. Also 3D modeling technique based on three-Dimensional GIS digital map and satellite tracking algorithm for visible satellite simulation system are discussed. Performance improvement of the availability and DOP were achieved by combining GPS with QZSS at urban environment of Seoul.

Visibility of the satellite navigation is related to a environmental condition of a receiver. Obstacles like buildings and trees in urban areas can block signals and have effects on accuracy and reliability of positioning. This paper presents a method of creating 3D analysis model of urban canyon of Seoul using three-Dimensional digital map. Analysis techniques of visible satellites with Ray-Polygon Collision Detection and validation of algorithm through field tests are discussed. We have compared and analyzed the visibility of GPS and Galileo with respect to separate and simultaneous tracking in view of DOP (Dilution of Precision) using the 3D GIS digital map.

COMS (Communication, Oceanography, and Meteorology Satellite) is the first Korean multi-purpose satellite which is planned to be deployed at the altitude of geosynchronous orbit above the Korean peninsular. Noting that COMS is composed of the main BUS structure, two deployable solar panels, one yoke, five reactions wheels, COMS is treated as a collection of 9 bodies and its nonlinear equations of motion are obtained using the multi-body dynamics approach. Also, a computer program is developed to analyze the COMS motion during the various mission phase. Quite often, the equations of motion have to be derived repeatedly to reflect the fact that the spacecraft dynamics change as its configuration, and therefore its degree of freedom varies. However, the equations of motion and simulation software presented in this paper are general enough to represent the COMS dynamics of various configurations with a minimum change in input files. There is no need to derive the equations of motion repeatedly. To show the capability of the simulation program, the spacecraft motion during the solar array partial and full deployment has been simulated and the results are summarized in this paper.

Minimum-time attitude maneuvers of three-axis stabilized spacecraft are presented to study the feasibility of using three magnetic torquers perform large angle maneuvers. Previous applications of magnetic torquers have been limited to spin-stabilized satellites or supplemental actuators of three-axis stabilized satellites because of the capability of magnetic torquers to produce torques about a specific axes. The minimum-time attitude maneuver problem is solved by applying a parameter optimization method for orbital cases to verify that the magnetic torque system can perform as required Direct collocation and a nonlinear programming method with a constraining method by Simpson's rule are used to convert the minimum-time maneuver problems into parameter optimization problems. An appropriate number of nodes is presented to find a bang-bang type solution to the minimum-time problem. Some modifications in the boundary conditions of final attitude are made to solve the problem more robustly and efficiently. The numerical studies illustrate that the presented method can provide a capable and robust attitude reorientation by using only magnetic torquers. However, the required maneuver times are relatively longer than when thrusters or wheels are used Performance of the system in the presence of errors in the magnetometer as well as the geomagnetic field model still good.

Recent progress on software engineering especially in object-oriented design concepts has enabled the development of the simulation models of satellite components in view of reliability and reusability. This paper proposes an useful satellite simulator framework using simulation service and generalized model design. The proposed method is verified by a prototyping in .NET/C# environment

Raman spectroscopy based non-destructive discrimination between natural and beryllium-diffused (Be-diffused) sapphires has been attempted. The initial examination of Raman image acquired on a sapphire revealed that microscopic structural and compositional heterogeneity was apparent in the sample, so acquisition of spectra able to represent a whole body of sapphire rather than a localized area was necessary for a reliable discrimination. For this purpose, a wide area illumination (WAI) scheme (illumination area: 28.3mm(2)) providing a large sampling volume was employed to collect representative Raman spectra of sapphires. Upon the diffusion of Be into a sapphire, the band shift originated from varied lattice structure by substitution of Be at cation sites was observed and utilized as a valuable spectral signature for the discrimination. In the domain of principal component (PC) scores, the groups of natural and Be-diffused sapphires were identifiable with minor overlapping and the cross-validated discrimination error was 7.3% when k-Nearest Neighbor (k-NN) was used as a classifier.

Supervised neighborhood preserving embedding (SNPE), a nonlinear dimensionality reduction method, was employed to represent near-infrared (NIR) and Raman spectral features of agricultural samples (Angelica gigas, sesame, and red pepper), and the newly constructed variables were used to discriminate their geographical origins. This study was done to evaluate the potential of SNPE for recognizing minute spectral differences between classes by preserving local relationships, in comparison with widely adopted linear feature representation methods such as principal component analysis (PCA) and partial least squares (PLS). For this purpose, diffuse reflectance NIR spectral datasets of Angelica gigas, sesame, and red pepper, and a Raman spectral dataset of the same red pepper were prepared. The spectra were represented into new variables in reduced dimensions by PCA, PLS, neighborhood preserving embedding (NPE), and SNPE, and the represented variables were used to determine the geographical origins of samples by using the k-nearest neighbor (k-NN) and support vector machine (SVM). The combination of SNPE and SVM differentiated the geographical origins with improved accuracy. Overall results demonstrate that SNPE is a valuable alternative feature representation method, especially when complex and highly overlapping vibrational spectra are used for analysis.

In this paper, we propose a novel L5 tracking scheme for QZSS satellite using L1/L5 synchronization characteristics in the L1/L5 receiver. The QZSS consists of a multiple number of satellites that fly in the orbit passing through the near zenith over Japan. The Michibiki, the first QZSS satellite, is transmitting all the positioning signals including the L1/L5 signals. As the code length of L5 signal is 10- times that of L1 signal, the L5 acquisition process takes too much time. To reduce this acquisition processing time, a higher number of correlators should be used in the acquisition module. These makes the hardware complexity and the computation power increase. As the proposed scheme uses the L1 tracking results such as the PRN, bit synchronization, and Doppler frequency, it doesn't need the extra L5 acquisition module and provides fast and stable tracking of L5 signal. The feasibility of the proposed scheme is demonstrated by processing L1/L5 signal transmitted from the QZSS satellite.

In this study, numerical simulation of airframes separating from a missile system has been preformed. For the time-accurate trajectory simulation, six D.O.F equations of motion of multiply connected bodies were derived and these equations have been coupled with the unstructured overset mesh technique for the treatment of independent mesh blocks moving with each body component. Applications were made for the simulation of the airframe separation at missile angles of attack of 0 and 5 degrees. It was demonstrated that the present method is efficient and robust for the prediction of unsteady time-accurate flow fields involving multiple bodies in relative motion.

In this paper, we present design features, implementation, and validation of a satellite simulator subsystem for the Korea Multi-Purpose Satellite-2 (KOMPSAT-2). The satellite simulator subsystem is implemented on a personal computer to minimize costs and trouble on embedding onboard flight software into the simulator. An object-oriented design methodology is employed to maximize software reusability. Also, instead of a high-cost commercial database, XML is used for the manipulation of spacecraft characteristics data, telecommand, telemetry, and simulation data. The KOMPSAT-2 satellite simulator subsystem is validated by various simulations for autonomous onboard launch and early orbit phase operations, anomaly operation, and science fine mode operation. It is also officially verified by successfully passing various tests such as the satellite simulator subsystem test, mission control element system integration test, interface test, site installation test, and acceptance test.

A communications satellite system placed in three-Lagrange points, L3, L4, and L5, of the restricted three-body problem in Earth-Moon system is proposed in this paper. LEO satellite constellation has been another choice of communications system. The proposed system which is alternatives of limited geostationary orbit resources, has some weak points such as long distance from the Earth, relatively expensive launch cost, long delay time, more required power, and so on. It has good points like less efforts (fuel) for station keeping, less eclipses, etc. This system has limitations for applications to provide commercial services but it is still some attractive points.

The design feature of KOMPSAT-2 simulator based on object oriented design methodology in terms of unified modeling language (UML) has been discussed in this paper. Also, we present how to embed flight software into the simulator. Flight software em-bedding for KOMPSAT-2 simulator is compared to that of the KOMPSAT-1 simulator.

The GNSS(Global Navigation Satellite System) is used widely and generally these days. The satellite navigation system provides navigation service globally and doesn"t need an extra cost to use. Thus this system is portrayed as public service. But this system has a weak point. The satellite signal strength is very weak on the ground so this system is vulnerable against interference signal. When the GNSS interference signal is induced, the receiver cannot operate normally. The interference is presented by jamming or spoofing about GNSS signal. The effect of the interference can be done in various field from car navigation to national infrastructure like mobile communication, power plant, etc. ETRI(Electronics and Telecommunications Research Institute) developed GPS Jamming monitoring system for monitoring interference of GNSS signal. The developed GPS Jamming monitoring system has the functions which are jamming & spoofing detection and jamming location with direction finders. Among the technologies of GPS Jamming monitoring system, this paper describes spoofing detection module. This module monitors GPS signal and detects the spoofing signal with measurement and message of receiver. ETRI performed the functional test of developed spoofing detection module through the spoofing signal generation equipment. In this test, we confirm that the spoofing signal is induced in GPS receiver and verify the performance of spoofing detection.

GPS is widely used in the location based service and the telematics service. And communication systems, electrical power grids, and financial networks also rely on GPS for synchronization and operational efficiency. GPS applications are newly being developed and becomes very critical infrastructure. However, GPS couldn’t be used by intentional interference signal of even low power, low cost transmitters. In order to prevent the damage caused by illegal interference signal to GPS, GPS interference monitoring system(IMS) should be developed and operated. So, this paper presents the development and the test results of the GPS IMS which provides the detection, the direction finding and the location of GPS interference signal. The main functions are verified by test results of the interference test-bed environment.

In this paper, we compared and analyzed the performance of generated GPS signal by GPS L1 signal generator with Live GPS signal using the U-Blox receiver. Generally GPS Receiver calculates the position of the satellite by using the ephemeris data received from GPS satellites, and calculates the position of the receiver using the pseudorange. GPS satellites, so it is synchronized, it will then transmit the same data at the same time but the pseudorange because the distance between each satellite and receiver is different. However, For the same signal as the GPS provides the receiver, signal generator is required to generate the RF signal that reflects the pseudorange that different are measured to the same signal as the GPS, not the GPS satellites. This paper provides an overview of a device which can generate an L1 GPS signal at the same time as the GPS signal, and compared with Live GPS signal performance verification for this. As a result, we can check that the navigation of the GPS signals generated in synchronization with the GPS signal can be maintained in the same manner as Live GPS, and the relative pseudorange error between channels are kept constant when generating signals of the long.

The problem of spacecraft rendezvous is studied, using sliding mode control in the presence of the earth's gravitational perturbation. The impulsive solution of Lambert's problem is obtained using the combined equations method to minimize total ΔV via an iterative method, and it is used as the desired trajectory for the rendezvous. In this paper, a two-step sliding mode control method is introduced for solving the rendezvous problem with finite-thrust including unmodeled dynamics. The thrust-coast-thrust type control laws for the system to follow the desired trajectories are represented and resultant trajectories are close enough to the Lambert's orbit with comparable amount of ΔV to the Lambert's impulsive solution. All state variables matched the final boundary conditions reasonably well at the end of maneuver.

Attitude determination and control of satellite is important component which determines the accomplish satellite missions. In this study, attitude control using reaction wheels and momentum dumping of wheels are considered. Attitude control law is designed by Sliding control and LQR. Attitude maneuver control law is obtained by Shooting method. Wheels momentum dumping control law is designed by Bang-Bang control. Four reaction wheels are configurated for minimized the electric power consumption. Wheels control torque and magnetic moment of magnetic torquer are limited.

Galileo system is being under the in-orbit validation (IOV) and and its constellation consists of Proto Flight Model (PFM) and Flight Model 2 (FM2) launched in October 2011 and FM3 and FM4 launched in October 2012. The researchers of the NAVIS Centre and the European Space Agency (ESA) have announced the signal tracking of all the four satellites and the first determination of a ground location, respectively. This paper for the first time, presents E1 acquisition and tracking results using our own receiver after receiving the signals of all the four Galileo satellites at the same time, in Korea. The simulation results show that the SW based Galileo E1 receiver of ETRI successfully processes the signals of all the four Galileo satellites.

In this paper, we introduce the type of spoofing signal and the method of spoofing mitigation. The spoofing has three type: simplistic, intermediate, sophisticated and we will be interested in the intermediate spoofing. The intermediate spoofers synchronize its counterfeit GNSS signals with the current broadcast GNSS signals. So, if the receiver is attacked by a spoofer, it should be able to detect the spoofing signal through the absolute and relative GNSS signal strength, signal strength changing rate, Bound and compare range rates, etc. There are two way to mitigate spoofing signal, elimination of spoofing channel through the signal processing and counterbalance of spoofing signal through the RF phase control. For simulation, we generated the intermediate spoofing signal using the software GNSS signal generator simulator(SGGS), the intermediate spoofers synchronize its counterfeit GPS signals with the current broadcast GPS signals and generated the anti-spoofing signal to mitigate the spoofing signal. The software GPS receiver simulator(SGRS) received the mixed signal the spoofing, anti-spoofing and normal signal from SGGS, and process the signals. In paper, we can check that the DLL and PLL tracking loop error are generated and pseudo-range is changed linear according to mitigate to spoofing signal when the anti-spoofing signal is entered. As a result, we can check that navigation solution is changed from abnormal by spoofing signal to normal by anti-spoofing signal.

Non-linear feature extraction methods, neighborhood preserving embedding (NPE) and supervised NPE (SNPE), were employed to effectively represent the IR spectral features of stomach and colon biopsy tissues for classification, and improve the classification accuracy for diagnosis of malignancy. The motivation was to utilize the NPE and SNPE's capability of capturing non-linear spectral behaviors by simultaneously preserving local relationships in order that minute spectral differences among classes would be effectively recognized. NPE and SNPE derive an optimal embedding feature such that the local neighborhood structure can be preserved in reduced spaces (variables). The IR spectra collected from stomach and colon tissues were represented by several new variables through NPE and SNPE, and also by using the principal component analysis (PCA). Then, the feature-extracted variables were subsequently classified into normal, adenoma and cancer tissues by using both k-nearest neighbor (k-NN) and support vector machine (SVM), and the resulting accuracies were compared with each other. In both cases, the combination of SNPE-SVM provided the best classification performance, and the accuracy was substantially improved compared to when PCA-SVM was used. Overall results demonstrate that NPE and SNPE could be potential feature-representation strategies useful in biomedical diagnosis based on vibrational spectroscopy where effective recognition of minute spectral differences is critical.

The Michibiki is the first QZSS satellite, which was launched by a H-IIA rocket departing from the Tanegashima in Japan on 11 September, 2010 and technical and application verification of the satellite is being carried out. This paper presents the results obtained from processing of the L5 signal transmitted from the QZSS satellite. The QZSS L5 signal is collected in ETRI, Korea. And then, the acquisition and tracking are performed by the L5 software receiver implemented by ETRI. The tracking loop of FLL, PLL, and DLL, the EPL correlator output, and the C/No output results show that the QZSS L5 signal is normally processed. Finally, the paper demonstrates that the QZSS L5 signal could be used as GPS satellite based augmentation system in Korea as well as Japan.

A multi-mission GEO satellite, COMS has three payloads including Ka-band communications, GOCI, and MI. COMS SGCS is the only system for monitor and control of the satellite in orbit. In order to fulfill the mission operations of the three payloads and spacecraft bus, COMS SGCS performs the following functions such as reception and processing of telemetry data via S-band link, planning and transmission of telecommand, tracking and ranging of the satellite, control and monitoring of SGCS equipment, analysis and simulation of the satellite, processing and analysis of flight dynamics data, and mission scheduling and reporting. By the proper functional allocations, COMS SGCS is divided into five subsystems such as TTC, ROS, MPS, FDS, and CSS. COMS SGCS is linked with MSC, KOSC, and IDACS for satellite related data exchange. The software in the COMS SGCS is designed using the object-oriented methodology and implemented using Microsoft C# .NET environment on Intel microprocessor based computers. The hardware in the COMS SGCS includes 13-m S-band mono-pulse Cassegrain antenna and RF/BB equipment. In this paper, development of the COMS SGCS is described with respect to system functional allocations, software and hardware design, system implementation, and system test.

This paper proposes the advanced fine-acquisition scheme using the E5a signal transmitted from the Galileo GIOVE-B satellite. The proposed approach is based on the code phase changes which occur during the acquisition processing time originating in the Doppler frequency. The proposed scheme detects a fast code phase within about 1 chip near the estimated code phase and improves the accuracy of the Doppler frequency in comparison with the conventional scheme. The feasibility of the proposed schemes is demonstrated through simulation

Raman spectroscopy has been extensively used for analysis of diverse polymer samples. Normally, Raman spectral collection of samples is routinely performed at room temperature for convenience. However, the feasibility of improving spectral selectivity and the resulting quantitative accuracy, when samples are measured at nearly cryogenic temperature, has not been investigated. For this purpose, we attempted to measure the density of polyethylene (PE) pellets at cryogenic temperatures and the resulting accuracies were compared with that from room temperature measurement. Initially, each of 25 PE sample was allowed to cool down to cryogenic temperature and the corresponding Raman spectra were continuously collected while the temperature of sample increased. When the temperature of sample was at cryogenic temperature, the resulting band widths were narrower compared to those at room temperature, thereby improving the accuracy of density measurement. In overall, the proposed Raman scheme is simple and efficient; therefore, it could be further applied for analysis of other polymers.

This paper presents the PC based experimental software receiver which has been recently extended to a high bandwidth multiple frequency LI signal for GPS and El signal software receiver. The presentation briefly touches upon on signal tracking using prototyping hardware antenna, RF-IF section and software baseband section. In this paper, the efficient algorithms are developed about the signal acquisition and tracking parts in order to obtain the accuracy pseudorange. Finally, the pseudorange is calculated through the relative channel delay received through the different satellite of LI frequency band.

COSPAS-SARSAT system which consists of space segment and ground segment provides a distress alert and the position information for a distressed ship or airplane with beacon equipment. Currently, COSPAS-SARSAT system provides the LEOSAR service which is called to the first generation, and the GEOSAR service as the second generation. The GEOSAR service provides position accuracy better than the LEOSAR service because the second generation 406 MHz beacon allows for the encoding of position data in the transmitted 406 MHz message, thus providing for quasi-real time alerts and position information through the GEOSAR service. ETRI developed emergency position indicating radio beacon (EPIRB) as the second generation 406 MHz beacon for use in maritime applications. Design and implementation aspects of the EPIRB developed by ETRI are presented. Also, performance is presented through the experiment.

The modeling of satellite multi-body dynamic is quite complicate process. In developing satellite simulator, it’s proper to use multi-body dynamics in modeling satellite attitude dynamics. We will introduce the attitude dynamic module that is able to cover various satellites and operational phases. This approach may improve portability of satellite modeling. The generalization of multi-body attitude dynamics model can be used to analyze orbit and attitude dynamic of satellite. It is very useful for various satellites system and applying to other system with several parameters change.

Modernized GPS and Galileo system will be available to civil users, thus there is a need for unified platform that can receive multi-frequency signals of Galileo/GPS to develop and test a variety of applications. ETRI involved in developing technologies of GNSS ground infrastructure and next generation search and rescue beacon from 2007 up to 2010. We are going to develop high performance S/W receiver for feasibility study on developing a receiver for GNSS ground sensor station for the program. In order to test and verify S/W receiver prototype digitized IF signal generator is developed. The experimental result for the S/W receiver is presented in future.

COSPAS-SARSAT is the search and rescue system for providing a distress alarm and a position identification using an international satellite system and ground facilities. Aviators, mariners and land users worldwide are equipped with COSPAS-SARSAT distress beacons, which could help save their lives in emergency situations anywhere in the world. As the existing COSPAS-SARSAT system is generally operated by LEO(Low-altitude Earth Orbit) Satellite System, the time from the distress beacon to the rescue is more than 1 hour with average and the accuracy of the distress location is about 5 Km. In order to overcome this drawback, the development for the next generation SAR(search and rescue) system which uses the MEO(Middle-altitude Earth Orbit) satellites is going on the Galileo project. EU is developing this project for the full operation capability in 2011, and this project will have SAR payloads and support to the search and rescue service-herein called SAR/Galileo. SAR/Galileo will have the performance of a few meter accuracy, within 10 minutes to rescue from reception of distress messages, and Return Link Service(from the SAR operator to the distress emitting beacon), thereby facilitating more efficient rescue operations and helping to reduce the rate of false alerts. As the disaster is larger every year, the next generation SAR/Galileo ground system is urgently needed for the lifesaving. So, this research for developing the SAR/Galileo ground system including the SAR/Galileo beacon and the ground station is very timely and is important. This paper presents the procedures and the strategies for the participation, the potential development field, and the propulsion organization for developing the SAR/Galileo ground system in Korea.

In this paper, a hierarchical modulation scheme(and also known as embedded, multi-resolution, or asymmetrical constellation scheme) is studied for transmission of multimedia system. A hierarchical modulation scheme is presented to upgrade an existing digital broadcast system by adding more data stream in its transmissions. The hierarchical modulation is composed of a basic constellation, which is the same as in the original system, and a secondary constellation, which carries the additional data for the upgraded system. The upgraded system with the hierarchical modulation is backward compatible (BC mode) in the sense that receivers that have been deployed in the original system can continue receiving data in the basic constellation. Hierarchical receivers can be designed to receive data carried in the secondary constellation, as well as those in the basic constellation. Specifically, we propose general design guidelines for multimedia transmission over AWGN channels with an hierarchical Amplitude Phase Shift-Keying(APSK) constellation.

This paper propose new bit mapping based on amplitude phase shift keying (APSK) modulation with application to satellite broadband communications in the DVB-S2 standard The APSK modulation outperforms classical 16-QAM and 16-PSK over a typical satellite nonlinear channel due to its intrinsic robustness against the High Power Amplifier (HPA) nonlinear characteristics. The proposed bit mapping considers non-linearity of HPA in the APSK modulation and the performance of APSK modulation for the proposed bit mapping has been compared to the conventional bit mapping.

GNSS Digitized IF Signal Simulator (GDISS) is being developed by ETRI as a part of development of software- based Test & Evaluation Facility which will provide test and evaluation environment for various software level application and navigation algorithm in GNSS. GDISS will provide digitized IF data of GPS and Galileo signals. In this paper, GDISS prototype for L1, L2C, and E1(B&C) is developed and verified. The proposed prototype has good modularity and flexibility to add conveniently various modelings like ionospheric model, tropospheric model, multipath model, satellite clock model, etc. It will be verified by the commercial S/W receiver, Nordnav, and the S/W receiver implemented by CNU(Chungnam National University).

The GNSS uplink station is to track the GNSS Satellites in look angle at elevation angle of over 5 deg. by program tracking. Also, during program tracking, the uplink station is to uplink the GNSS mission data, i.e. to receive the data processed in the GNSS control center (GCC) and transmits it to the GNSS satellites. This paper analyzes the key requirement of the uplink station to meet the operation of Galileo satellite tracking and the transmission of uplink signal data from GCC such as frequency and bandwidth. Also this paper deals with other requirement such as wind velocity, and operation conditions.

In this paper, a method of station keeping strategy using relative orbital motion and numerical optimization technique is presented for geostationary spacecraft. Relative position vector with respect to an ideal geostationary orbit is generated using high precision orbit propagation, and compressed in terms of polynomial and trigonometric function. Then this relative orbit model is combined with optimization scheme to propose a very efficient and flexible method of station keeping planning. Proper selection of objective and constraint functions for optimization can yield a variety of station keeping methods improved over the classical ones. Nonlinear simulation results have been shown to support such concept.

Satellite system has lots of fault causes. For some communications satellite systems, fault management and data preservation are required to exchange data continuously and provide broadcasting service. In this paper, we have proposed fault management of satellite system using penalty method, data buffer and recovery manager. The penalty manager imposes penalty according to fault degree and manages fault quantitatively. Data Buffer has the function to store data in fault situation and prevent data damage. Recovery manager performs system monitoring and to operates recovery process in fault situation. Proposed method is fundamental concept of the architectural characteristics and enhances satellite fault management performance. This capability permits the satellite to detect and correct some of its own failures autonomously. Also, the effect of penalty method and data buffer on fault management design has been discussed.

In this paper, we present design and implementation features and validation of KOMPSAT-2 simulator (SIM). The SIM is implemented on PC server to minimize costs and troubles on embedding onboard flight software into simulator. Object oriented design methodology is employed to maximized S/W reusability, and XML is used for S/C characteristics data, TC, TM and Simulation data instead of expensive commercial DB. Consequently, we can reduce costs for the system development, efforts on embedding flight software. A simulation for science fine mode operation is presented to demonstrate the overall validation of SIM. SIM has been verified officially by various tests such as SIM subsystem test, MCE system integration test, interface test, site installation test, and acceptance test. They were performed successfully.

A shortcut biological nitrogen removal (SBNR) process was operated to treat an ammonium rich landfill leachate using a pilot-scale reactor. The SBNR process was intended to oxidize ammonia to nitrite and, then, to reduce it to nitrogen gas. When the hydraulic retention time was 4-3 days, a half of the ammonium oxidized was accumulated as nitrite in the oxidation tank. The nitrite was denitrified completely in the anoxic tank when recycled. The average free ammonia (FA) concentration in the ammonium oxidation tank was 3.7 mg/L. The specific substrate utilization rates of ammonium oxidizers and nitrite oxidizers were investigated at varying FA concentrations through batch experiments. The highest specific ammonium oxidation rate was observed when the FA concentration was 10 mg/L. The rate decreased slightly when the FA concentration was increased to 20 or 50 mg/L, or decreased significantly when it was 5 mg/L. In case of nitrite oxidation, the specific nitrite utilization rate decreased significantly with increasing FA concentration up to 10 mg/L. Consequently, the optimal FA concentration in leachate treatment was 10 mg/L for maximum nitrite accumulation and maximum ammonium removal, or 5 mg/L for lower ammonium concentration and reasonable nitrite accumulation.

The simulation of LEOP operations was presented. A generic software satellite simulator was used for the analysis and verification of LEOP operations. A specific spacecraft model was implemented in the simulator for the LEOP operation scenario. The satellite model includes spacecraft subsystems and the flight dynamics models. LEOP simulation was performed by the stored relative time command set in the on-board flight software that was implemented on the simulator. The simulation started from the separation of a launch vehicle and executed solar array deployment, deployment test, and activation of sun point mode. Simulation results of earth searching operation and orbit adjusts maneuver are also provided.