Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011最新文献

{"title":"Rasat ADCS flight software testing with Dynamic Attitude Simulator Environment","authors":"Ç. Yavuzyilmaz, M. Akbaş, Yusuf Acar, Farid Gulmammadov, Ozgur Kahraman, Yuksel Subasi, N. Ertongur, C. Tufekci","doi":"10.1109/RAST.2011.5966987","DOIUrl":"https://doi.org/10.1109/RAST.2011.5966987","url":null,"abstract":"RASAT is a 3-axis stabilized earth observation satellite to be launched to a sun-synchronous LEO (Low Earth Orbit ) orbit. The primary design of attitude determination and control system (ADCS) flight software is performed by utilizing combination of MATLAB® and C environments. MATLAB environment ensures an easy design and test platform for quick algorithm simulation. After MATLAB simulations are performed successfully, the same algorithms are coded in C language to obtain the source code for the flight software. In the further development stage, Dynamic Attitude Simulator Environment (DASE) is used for simulating the real data to run the flight code in onboard computer. DASE software simulates the attitude and the orbit dynamics of the satellite and generates the corresponding sensor and actuator signals by using the satellite data bus as if they were received from the real sensors and sent to real actuators. Thus, DASE provides a suitable environment necessary to test and verify controllers and estimators as it simulates the satellite dynamics well before the launch. In this work, various aspects of ADCS flight code testing are considered and presented, such as sensor processing issues and actuator limitations. The success in realizing RASAT's operational phases are demonstrated by comparing the DASE-results with the desired behavior of RASAT in space. Two fundamental operational scenarios are presented as the result of simulations: 1) satellite de-tumbling after launcher separation and 2) 3-axis nadir pointing control.","PeriodicalId":285002,"journal":{"name":"Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128727858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An overview of solar resource assessment using meteorological satellite data","authors":"O. Gurtuna, A. Prevot","doi":"10.1109/RAST.2011.5966825","DOIUrl":"https://doi.org/10.1109/RAST.2011.5966825","url":null,"abstract":"Earth observation data from meteorological satellites provide essential information for solar resource assessment (SRA). SRA is the statistical characterization of solar radiation at a specific location on Earth and it is a key part of feasibility studies for solar thermal and solar photovoltaic projects. Cloud climatology and the Clear Sky model are the two main building blocks of any satellite-based resource assessment method. This paper provides an overview of SRA methods and provides examples of data products derived from satellite images.","PeriodicalId":285002,"journal":{"name":"Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011","volume":"106 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115153442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Considering trajectory outlier detection methods in verification of navigation satellite messages","authors":"L. Altay, S. Kurnaz, O. Kalipsiz","doi":"10.1109/RAST.2011.5966836","DOIUrl":"https://doi.org/10.1109/RAST.2011.5966836","url":null,"abstract":"Approximately a thousand artificial satellites operate in orbit around their parent's bodies. These man-made celestial objects are employed for observation, communication, navigation, weather forecast and research purposes. Sending high accuracy ephemeris and clock offset data to Earth; navigation satellites help receivers estimate their location and precise time. The accuracy of receivers' location information and transmitting time data depends on compensable and noncompensable errors. Compensating the perturbations, Augmented GNSS propagate error correction signals based upon carefully surveyed locations. Notwithstanding Augmented GNSS ensures receivers' collecting reliable, accurate and available navigation signals and correction even in globally spoofed medium, local spoofers and jammers still are sources of threat. At this multi-GNSS age, users want to know whether the announced or calculated data are valid or not. To confirm the received signals, there are techniques that necessitate additional devices, antenna arrays and high computational cost. In this paper, we want to get researchers attention to trajectory outlier detection methods as an auxiliary to validate the signals the navigation satellite or Augmented GNSS send. Considering trajectory outlier detection methods in verification of navigation satellite messages is relatively low cost and not requiring additional device. In this approach, although a simple GNSS receiver is adequate, receiving the Augmented GNSS signal is preferable.","PeriodicalId":285002,"journal":{"name":"Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122024928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Solid methane hybrid rocket engine. Regression speed increase by oxidizer doping and embedding wires. Vehicle optimization application through motor parameters.","authors":"F. Mingireanu","doi":"10.1109/RAST.2011.5966928","DOIUrl":"https://doi.org/10.1109/RAST.2011.5966928","url":null,"abstract":"This paper presents a novel fuel to be considered for hybrid rocket motors: solid methane. We are showing the potential that this fuel has for hybrid rocket motors from technical perspective as well as from economical perspective. We present an internal ballistic model used to design a hybrid rocket motor with solid methane. We also present a comparison table for solid methane and various cryogenic and non-cryogenic oxidizers. The maximum specific impulse is obtained for the solid methane-LOX pair with a value of ∼315 seconds under specific conditions. Although a solid methane-LOX motor shows higher than averages values for the regression speed, these values are still low by performance standards. We present two models that predict the regression speed increase for embedding wires and for oxidizer doping with a factor of ∼2–3. An experimental setup that can be used to verify these models is further presented in the paper. Finally, we present a potential application for solid methane hybrid rocket motors in the form of an upper stage propulsion unit for orbital/suborbital vehicles. We find a practical interdependence relation between structural optimization (dry mass) of the launcher and the performance parameters of the motor. We present a study case of such a vehicle intended to place a 50 kg payload on low earth orbit (300 to 500 km altitude). Developing such a launcher is both environmentally safer than current approaches and economically more efficient because methane reserves are a rich resource worldwide.","PeriodicalId":285002,"journal":{"name":"Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122660584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of MERIS ocean color products using in situ data collected in the Northwestern Black Sea","authors":"V. Slabakova, Natalia Slabakova, O. Hristova, B. Dzhurova","doi":"10.1109/RAST.2011.5966807","DOIUrl":"https://doi.org/10.1109/RAST.2011.5966807","url":null,"abstract":"In this study the performance of Medium Resolution Imaging Spectrometer (MERIS) geophysical products were evaluated using in situ measurements in northwestern part of the Black Sea. The in situ chlorophyll a (Chl-a), total suspended matter (TSM) and Scechi disk depth (SDD) were collected from two Institute of Oceanology, BAS cruises during spring season of 2006 and 2009. A strict comparison method between two data sets was adopted resulting in 27 and 33 match ups for TSM and Chl a respectively. The method comprised the arithmetic average of valid MERIS values calculated over the 3 × 3 - pixels square found within time difference of ± 3 h from the in situ measurement. Additionally, classification of the in situ data was performed, in order to assess accuracy of MERIS algal_2 and TSM products in respect to the sea water with different optical properties. The in situ data were subdivided into three groups to represent clear, moderate turbid and turbid waters by applying K - mean clustering method on the measured concentrations of Chl-a, TSM and transparency. Statistical analysis of MERIS derived TSM and Chl-a and in situ data were carried out for the different water types. In the case of TSM concentrations, was found a reasonably good agreement between two data sets in clear and moderate turbid waters. The estimated R2 are greater than or equal to 0.66 and log_RMS differences for clear and moderate turbid waters ranging between 0.09 g/m3 and 0.19 g/m3. The similar correlations were estimated for Chl-a concentrations, but the value for log_RMS in turbid waters is higher to those obtained for TSM. For both variables, the best results of comparison were found for the moderate turbid waters, that corresponding to high coefficients of determination (R2>0.75) and small log_RMS differences of 0.1 mg/m3 for Chl-a and 0.09 g/m3 for TSM. The present study suggested that MERIS Case 2 products are reasonably accurate in moderate turbid shelf waters, but not yet reliable in turbid coastal waters of the northwestern Black Sea.","PeriodicalId":285002,"journal":{"name":"Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131491033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design of a fuzzy variable structure controller for controlling satellite attitude suffering from sensor data delay","authors":"B. Erkal, O. Kaynak","doi":"10.1109/RAST.2011.5966900","DOIUrl":"https://doi.org/10.1109/RAST.2011.5966900","url":null,"abstract":"Time delays in sensor data is one of the main issues in controlling the attitude of a satellite. Although, there exists methods to alleviate the problem, it is preferable to have a robust controller which can handle delays in sensor data well. In this study, a new method is proposed in the literature which uses an enhanced fuzzy variable structure controller that can handle delays in sensor data well. However it displays a steady state error. The novelty in this study is that the steady state error is handled using an integral term so that an acceptable performance is obtained.","PeriodicalId":285002,"journal":{"name":"Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125548972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comparative study of dynamics models for satellite formation flying - Cartesian ordinary differential equations description","authors":"M. Navabi, M. Barati, H. B. Khamseh","doi":"10.1109/RAST.2011.5966959","DOIUrl":"https://doi.org/10.1109/RAST.2011.5966959","url":null,"abstract":"Formation flying is regarded as a feasible solution to bring order of magnitude improvements is performance and capabilities of our space assets. To take full advantage of the benefits offered by formation flying concepts, it is necessary to develop and examine its dynamics models. In this paper, four models namely Perturbed Nonlinear Model, Unperturbed Nonlinear Model, Linear Elliptic Model and Linear Circular Model are studied. Also, an error index is given to measure accuracy of each model. Based on our simulation results, compared to Perturbed Nonlinear Model as the reference, minimum error index was observed in the Unperturbed Nonlinear Model. Due to linearization, the Linear Elliptic Model exhibits some error, as the formation size expands. Error index in the Linear Circular Model increases as the relative distance increases. Furthermore, its error index experiences rapid increase, even for small eccentricities. Considering the effects of these error sources on each model, one may be able to choose the appropriate model according to the desired accuracy for a given mission.","PeriodicalId":285002,"journal":{"name":"Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130431832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design and implementation of a rover-back CANSAT","authors":"M. Aydemir, M. Celebi, Serdar Ay, E. V. Vivas, Fredy Calle Bustinza, D. Phan","doi":"10.1109/RAST.2011.5966952","DOIUrl":"https://doi.org/10.1109/RAST.2011.5966952","url":null,"abstract":"In this study, a CanSat with capability of returning back to target is designed amd implemented. The device is a part of project that has been implemented during the CLTP (CanSat Leadership Training Program) in Wakayama University. The CanSat is controlled by a state-of-the-art MBED 32-bit microcontroller. The main components are the pressure, ultrasonic, gps sensors and the 2.4 GHZ transmitter. The mission is planned for two stages which are flight back to the target by a paraglider and rovering on the ground on wheels. The process will be monitored on the ground station via the GoogleEarth software. The electronics&hardware design and the control algorithm is discussed in depth in this paper.","PeriodicalId":285002,"journal":{"name":"Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011","volume":"20 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120851522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Use of technology virtual reality for the study of human - operator in extreme conditions","authors":"P. Getsov, V. Popov, Z. Hubenova, G. Sotirov, K. Metodiev, S. Tanev, L. Aleksiev, S. Doshev","doi":"10.1109/RAST.2011.5966957","DOIUrl":"https://doi.org/10.1109/RAST.2011.5966957","url":null,"abstract":"Astronaut's training includes self-forming a mental model of the upcoming flight. In fact, this model consists of images of the actual and forthcoming situation of the upcoming space flight, formed on the basis of information surplus and multiple models, more or less adequate to the situation. In this regard, the article proposes an experimental methodology to develop a conceptual model and study of basic human mental models as a control system in case of perception, accumulation and processing information and knowledge, making decisions and performing control activities in extreme conditions. A discussion is held about the possibilities of applying the technology of virtual reality VR application in modeling and testing the man as a control system.","PeriodicalId":285002,"journal":{"name":"Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128876514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The nonlinear transverse vibrations of narrow microbeams by energy balance method based on collocation method","authors":"V. Tagiyev, S. Durmaz, M. O. Kaya","doi":"10.1109/RAST.2011.5966884","DOIUrl":"https://doi.org/10.1109/RAST.2011.5966884","url":null,"abstract":"In this paper, the microbeam, which incorporates with the mid-plane stretching effect and distributed electrostatic force, is considered. After the beam model is introduced briefly, the governing equation of motion of the microbeam is solved by the energy balance method (EBM). The first and the second order approximate periodic solutions are obtained and plotted for various values of the parameters of the equation. The numerical solutions (Runge-Kutta) are also computed to illustrate good agreement between both results.","PeriodicalId":285002,"journal":{"name":"Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133317751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}