- KA BAND RADIAL LINE SLOT ARRAY ANTENNA DESIGN FOR NEW DBS RECEIVE SERVICES
S.Z Iliya1, T. A Rahman1, I. Maina1, Akoma Henry2, Onuh Spencer2
1Wireless Communication Centre(WCC) UniversitiTeknologiMalaysia(UTM) Johor Bahru, Malaysia solozakwoi@gmail.com, tharek@fke.utm.my, imaina32@gmail.com, akomahenry@gmail.com, onuh.spencer@cstd.nasrda.gov.ng
2Center for Satellite Technology Development (CSTD) National Space Research and Development Agency (NASRDA) Obasanjo Space Center opposite Pyakassa Junction Airport Road Abuja, Nigeria
ABSTRACT: The increase in demand for capacity availability as well as the applicability for broadband services brings about the emergence of Ka Band as the band for future satellite operators. This submission attempts the design of the Ka band (21.4-22.0 GHz) Radial Line Slot Array (RLSA) antenna using CST 2014 for downlink applications purpose in future direct broadcast services. Simulated and measured S11 results are presented and compared with those of the Ku band DBS receive at (12.25-12.75 GHz) in terms of bandwidth availability, return loss and antenna directivity
Keywords–RLSA;Antenna; Directivity; Return loss; DBS.
- PRODUCTION AND CHARACTERIZATION OF AMORPHOUS ALUMINUM-COPPER ALLOY FOR AEROSPACE APPLICATIONS
Olayide R. Adetunji*1, Muyiwa M. Olukuade2, Bukola O. Bolaji3, Wojciech Simka4 & Maciej Sowa5
1&2 Mechanical Engineering Department, College of Engineering, Federal University of Agriculture, Abeokuta, Nigeria.
3 Mechanical Engineering Department, College of Engineering, Federal University of Oye-Ekiti, Oye-Ekiti, Nigeria.
4&5 Chemistry Faculty, Silesian University of Technology, Gliwice, Poland. adetunjiolayide@gmail.com;2348033467246
ABSTRACT: Aluminium (Al) alloys have been the primary material of choice for structural components of aircraft since about 1930. Although polymer matrix composites are being used extensively in high-performance military aircraft and are being specified for some applications in modern commercial aircraft, aluminium alloys are the overwhelming choice for the fuselage, wing, and supporting structure of commercial airliners and military cargo and transport. The main objective of this research is to produce and characterize amorphous Aluminium copper (Cu) alloy for high strength applications. High strength aluminium alloys have gathered wide acceptance in the fabrication of light weight structures requiring high strength-to-weight ratio such as transportable bridge girders, road tankers. High grade of both Aluminium and copper ingots were charged to a ceramic mould and put in an electric furnace in the ratio of 13:1 of Al and Cu respectively. The furnace temperature was set at 1300oC and after melting, ingot casting was done using plastic mould with sprayed water to achieve rapid cooling. An amorphous metal or glassy structure was produced from the ingot by super cooling through preheating the cast rod to 600oC and rapid cooled by water quenching. The glassy alloy rods and Al control sample were prepared for Scanning Electron Microscope (SEM), tensile and impact toughness characterizations. The results showed SEM images of the Al-Cu alloy and pure Al samples. The ultimate tensile strengths for Al-Cu and Al samples were 399 and 330 kg/m2 respectively. Similarly, the impact strengths obtained were 27.3 and 26.4 J. It can be concluded that glassy phase Al-Cu alloy was produced with high ultimate tensile strength and impact toughness. The SEM also confirmed the status of the alloy produced. The amorphous alloy produced is a good structural material for aerospace applications.
Keywords; Amorphous, Aluminium-Copper alloy, Characterization, High S
- Design and Analysis of a Simple UHF Passive RFID Tag for Liquid Level Monitoring Application
A. Atojoko1, O.Ilonah Centre for Satellite Technology Development, Abuja
ABSTRACT- Radio Frequency Identification(RFID) systems has gained increasing popularity with multiple deployments to existing wireless sensors in a view to achieve energy and overall operational efficiency at a much lower cost. This paper presents the design and analysis of a UHF (860-868MHZ) passive tag on the HFSS (High Frequency Structural Simulator) platform. It explores specific tag geometry characteristics that affect overall tag antenna performance (reflection co-efficient) and presents the optimised result. The simulation results and parametric analysis is presented. Further simulations on HFSS platform is carried out to theoretically demonstrate the reflections of the tag when deployed as sensors to multiple levels of a cistern.
Keywords: RFID, Passive UHF tag; Antenna; Radiation Pattern; HFSS.
- MODELLING OF TROPICAL RAIN RATE & RAINDROP SIZE DISTRIBUTIONS FOR APPLICATION IN RAIN ATTENUATION PREDICTION ON EARTH-SPACE PATHS
Orisekeh, Kingsley I. Centre for Satellite Technology Development National Space Research and Development Agency, Abuja
Email: kingsleyorisekeh@yahoo.com /08037786223
ABSTRACT: The enormous demands for fast, reliable and robust Communication systems has led to the use of higher frequency bands especially in the ku-bands and above, however Rain attenuation of signals is a going concern in Satellite Communications especially at frequencies above 10GHz. The strength of satellite signal can be drastically reduced under rain condition (absorption & scattering) causing low quality of service or complete outage. The rain fall rate, drop size distributions are parameters that degrade the reliability and performance of Communications links. The ability to model raindrop size distributions (DSD) will help in the understanding, predicting so as to mitigate any rain induced attenuation of communication signals within the earth-space path. Results from the studies shows that ITU-R model does not properly predict the rain attenuation in Africa (Tropical region) due to the cumulative distribution of rainfall rate, hence, more research should be carried out in this field. It is hopeful that the results presented from this paper will contribute to improvement in the accuracy of rain attenuation predictions for earth-space paths located in tropical regions which will ultimately assist designers and users of satellite communication have more reliable services at better quality and reduced costs.
Keywords- Satellite Communication Systems, ku-bands, Frequency, Rain Attenuation, Earth-Space path, ITU-R model, Cumulative distribution of Rainfall Rate, Drop Size distributions (DSD) Tropical regions.
- DESIGN AND ANALYSIS OF THREE IMPROVED LQG CONTROL ALGORITHMS FOR A LONGITUDINAL FLIGHT DYNAMICS OF A FIXED-WING UAV.
*Aliyu BK, Osheku C.A and Oyedeji E.O
Centre for Space Transport & Propulsion (CSTP), Epe Lagos-State
aliyukisabo@gmail.com,+2348028908182
ABSTRACT: The quest for better control algorithms for speed-accent and decent, attitude control and altitude hold control in Unmanned Aerial Vehicles (UAV) is endless. The modern control
theory of Linear Quadratic Gaussian is a combination of the Linear Quadratic Regulator
(LQR) with Kalman filter as the state observer. The drawback of this algorithm is that the
robustness of both the LQR and Kalman filter is lost as a result of the combination. In this
study we designed, simulated and analysed three novel Linear Quadratic Gaussian (LQG)
control system for a longitudinal dynamic of a fixed wing mini-UAV. Modelling results for
the small UAV using Aircraft DIGITAL DATCOM® are presented. The novelty of the
design is from the stand point of Kalman Filter, with Kalman gain obtained from the solution
to a Differential Riccati Equation (DRE) rather than the popular Algebraic Riccati Equation
(ARE). The formulated DRE to the Kalman filter design is solved as an Initial Value Problem
(IVP) in the MATLAB/Simulink®. The Kalman gain values were harvested at three different
point of the solution trajectory of the IVP of the Differential Riccati Equation and used in the
improved LQG control designs. A set-point control scheme was implemented tracking the
pitch angle for each of the algorithms. Using the robustness properties of the Kalman filter as
a benchmark, simulation result of the novel LQG algorithms were compared with that of the
LQG. Simulation results show that the novel algorithms outperformed the LQG by recovering some of the lost robustness of the LQG.
Keywords: UAV, LQG, MATLAB/Simulink, Riccati Equation, Aircraft DIGITAL
DATCOM
- COGNITIVE RADIO TECHNOLOGY: A VIABLE MEANS TO SUPPORT 5G NETWORK
B. A. Mohammed*, R. A. Abd-Alhameed*, M. C. Chukwu**, K. O. O. Anoh*, and A. S. Hussaini*
*School of Engineering and Informatics, University of Bradford, UK
**Centre for Satellite Technology Development, NASRDA, Abuja, Nigeria
{m.b.abubakar1; k.o.o.anoh; r.a.a.abd; shussaini2}@bradford.ac.uk, {chukwu.michael}@cstd.nasrda.gov.ng
ABSTRACT- Radio spectrum is facing a significant demand from the emergence of new wireless technologies, to complement applications such as Bluetooth, UWB, IEEE 802.11b/g, EGDE, UMTS, WiMAX and LTE. Poor allocations and extremely low usage of the allocated spectrum have become impediment to the exploitation and development of new wireless modernizations. This motive necessitates for application of cognitive radio for liable interaction with these levels of radio access technology for the improvement of global spectrum consumption within the heterogeneous radio environment. Implementation of cognitive radio will not only advance the usage but also respite some assigned effectively idle state spectrum resources. This makes the spectrum regulatory bodies to review policies in order to search for new inventive communication technology that can scrutinize and forward the spectrum in a more flexible and intelligent manner. The concept of cognitive radio is proposed to sort out the outstanding issues of unused radio spectrum and spectrum efficiency within the wireless communication service. This paper surveys and discusses the characteristics of cognitive radio and the challenges of RF front-end requirements, the impairments and the use of modern communication methods, for instance Vandermonde frequency division multiplexing (VFDM) technique, to cancel the interference of secondary
users on primary user resource.
Keywords—Cognitive radio; spectrum sensing; spectrum management; software defined radio; RF front-end; VFDM
- WIRELESS TECHNOLOGIES FOR THE GROUND TEST OF ATMOSPHERIC ROCKETS
O. O. Babayomi, C. A. Osheku, A.M. Chindo, B. K. Aliyu and A. O. Opasina
Centre for Space Transport and Propulsion, Epe, Lagos
National Space Research and Development Agency (NASRDA)
Federal Ministry of Science and Technology, FCT, Abuja, Nigeria
Email: babayomi@ieee.org
ABSTRACT – Wireless communications come into play in the remote control of a ground test system and the wireless data acquisition of physical quantities measured during a ground test. In this paper a study carried out on the reliability of short message service (SMS) of a national mobile communication service provider is reported. Results from the study indicate that only 1% of the total SMS sent were successfully delivered to the recipient within 5 seconds, 73% of short messages had a delivery latency of 10 – 29 seconds and 0.7% failed. Recommendations are made for applications of SMS to time-critical technologies and relays.
Keywords – SMS, GSM reliability, network characterization, ground rocket test, thrust sensor.
- RADIO-FREQUENCY IDENTIFICATION APPLICATION FOR THE REMOTE MONITORING OF ASSETS
Sadiq Umar1, Mobayode Olusola Akinsolu2, Onwuama Chukwuweike Ihunanya3, Ibekwe Marcus4
Centre for Satellite Technology Development (CSTD), Obasanjo Space Centre, Nigeria.
Sadiqumar200@yahoo.com1 , m_akinsolu@outlook.com2, onwuama.chukwuweike@cstd.nasrda.gov.ng3 , ibekwe.marcus@cstd.nasrda.gov.ng4
ABSTRACT: Radio-frequency identification (RFID) technologies offer an excellent platform in the development and deployment of intelligent wireless communication systems. In spite of the laudable feats recorded in the application of wireless communication systems for the remote monitoring of assets, wireless networks are still plagued with the challenges of optimal acquisition and retrieval of data dedicated for remote monitoring and supervised control. Though radio-frequency identification systems and its associated underlying technologies have been adopted in recent works to mitigate these evolving challenges, their deployment in the remote monitoring of assets still suffers from shallow utilisation. This work focuses on how radio-frequency identification (RFID) technologies constituting a wireless communication network can be optimally deployed in the remote monitoring of high profile assets. A basic master-slave radio-frequency identification (RFID) architecture adopting nodes enabled for satellite and or mobile communications is proposed based on existing global standards. In this work, it is also suggested that a group of collocated high profile assets make up a facility that can be monitored remotely using radio-frequency identification technology.
Key Words: Assets, GSM, Monitoring, Reader, Remote, RFID, Satellite, Slave-reader and Tag
- DESIGN OF A PACKET BASED DEMONSTRATION SATELLITE TEST BED
1 Engr. Dr. Sadiq Umar, 2 Engr. Ogbuokebe S.K, 3.Engr. Okeke. R.O
1.2 Electrical Engineering Research and Development , Centre For Satellite Technology Development , (CSTD), Abuja, Nigeria
3University of Port-Harcourt, Rivers, Nigeria
saqidumar200@yahoo.com , ogbuokebekc@yahoo.com , remyokeke@yahoo.co.uk
ABSTRACT: Satellite has a prominent role to play in Next Generation Networks (NGN) and internet services, hence the need to optimize Transmission Control Protocol (TCP) for Satellite links. This Research is experimental, assessing the impacts of Internet Protocol “IP” packet transmission over geostationary satellite link using Paradise Datacom satellite modems provided by department of Electronics Engineering, University of Surrey, Guildford, United Kingdom. The goal of this work was to design a satellite Test Bed and develop techniques for evaluating performance of TCP-IP packet transmission over satellite links. However, the experiment validated the theoretical analysis of Transmission Control Protocol Performance enhancement Proxy (TCP-PEP) as de facto solution for TCP limitations over Geostationary Earth Orbit (GEO) satellite link. Also, these set of test showed that PEP improves the performance of TCP significantly by 29.8% for the worst case over satellite IP network.
Key Words: TCP, IP, PEP, Satellite Test Bed, GEO, Paradise Datacom MODEM, FTP, HTTP
- SMALL CELLS AND SATELLITES: SERVING THE UNDER-SERVED, REACHING THE UNREACHABLE.
Sani Umar Abdullahi* and Fodio S Longman
Centre for Satellite Technology Development, National Space Research and Development Agency Abuja.
Email: abdullahi.umar@cstd.nasrda.gov.ng , fodiolongman@yahoo.co.uk
ABSTRACT: The ever increasing demand for data by consumers driven by advanced developments and affordability of smart phones and portable devices, coupled with other data-hungry services and applications are pushing operators and researchers to search for novel innovations for improving capacity and coverage. This has led to recent deployments of new, small-cell architectures which are of compact-size and much lower-power, which offer flexibility of easy installation and maintenance either for capacity enhancement for target areas such as hot-spots or for coverage extension into remote and rural or under-served areas. The use of these Small Cells not only improves the capacity and coverage of mobile networks, but also offers reduced power requirements, hardware costs and facilitates faster network expansion. However, the main obstacle to their effective roll-out by operators is the backhaul challenge especially for remote/rural areas where terrestrial fixed-line backhaul systems such as fibre or copper are neither practical nor economical. In such scenarios, one of the most ideal backhaul alternatives is Satellite, which provides quick deployment capability, much wider coverage, and significantly reduced capex relative to competing solutions. This paper therefore presents a technical and business case for the use of Small Cells in conjunction with Satellites with a view to opening up huge markets via collaboration between the mobile operators and satellite system owners, while offering significant improvements in the coverage and capacity needs of remote, rural or underserved end-users in a cost-effective and scalable manner.
Keywords: Small Cells, Backhaul, Satellite
- THE PLACE OF SPACE GEODESY IN GLOBAL EARTH OBSERVATION AT CGG TORO
Dodo, J. D.
Space Geodesy and Systems Division
Centre for Geodesy and Geodynamics
National Space Research and Development Agency
ABSTRACT: The Global Geodetic Observing System (GGOS) is established by the International
Association of Geodesy to integrate the three fundamental areas of geodesy (Earth’s shape, gravity field, and rotation), to monitor geodetic parameters and their temporal variations in a global reference frame; to provide products and services with the geodetic accuracy necessary to address important geophysical questions and societal needs, and to provide the robustness and continuity of service which will be required of this system in order to meet future needs and make intelligent decisions. The Global Geodetic Observing System (GGOS) integrates different space geodetic techniques such as Global Navigation Satellite Systems
(GNSS), Very Long Baseline Interferometry (VLBI), Satellite Laser Ranging (SLR), Interferometric Synthetic Aperture Radar (InSAR) and Doppler Orbitography and Radio positioning Integrated by Satellite (DORIS), models and analysis techniques for the purpose of ensuring long-term, precise monitoring of geodetic observables vital for monitoring Earth system processes. The Centre for Geodesy and Geodynamics Toro is one of the “Global
Candidate Core Sites” approved by (GGOS) for the integration of these techniques.This paper highlight the role of Space Geodesy as the driving force in Global Earth Observation in the determination and monitoring of geo-kinematics, Earth’s rotation and gravity fields, assessment of geo-hazards, anthropogenic hazards and in the design of early warning systems for hazard and disasters. In general, space geodesy provides products for Earth observation, science and influences many activities (e.g., building and management) in a modern society.
Keyword: Space geodesy, Global Earth Observation, GNSS, geo-hazards, geodynamics
- SPACE GEODESY RESEARCH AT THE CENTRE FOR GEODESY AND GEODYNAMICS (CGG) TORO
Dodo, J. D.
Space Geodesy and Systems Division
Centre for Geodesy and Geodynamics
National Space Research and Development Agency
ABSTRACT: Until recently, solid Earth studies often involve space-borne techniques, ranging from multispectral imaging to space-geodetic methods. However in the past several decades,
Space-based observations of the Earth have contributed powerfully to fields such as plate tectonics, seismology, and volcanology, as well as to studies of the geodynamic, mantle convection, and continental tectonics. Such investigations also provide insights into managing natural resources, understanding natural hazards, and predicting global environmental change. The Centre for Geodesy and Geodynamics (CGG) is among others charged with the responsibilities of carrying out earth observation research as well as monitor and predict geo-hazards using Space Geodetic and Geo-physical techniques for sustainable National Development. The Space Geodetic technique includes, Global Navigation Satellite
Systems (GNSS), Very Long Baseline Interferometry (VLBI), Satellite Laser Ranging (SLR),
Interferometric Synthetic Aperture Radar (InSAR), Doppler Orbitography and Radio positioning Integrated by Satellite (DORIS). This paper presents results of some research activities carried out using the Global Navigation Satellite System (GNSS) as the only available and the major component of Space Geodesy at the Centre for Geodesy and Geodynamics (CGG) Toro. The paper will also highlight on the on-going research.
Keywords: Space geodetic, GNSS, geo-hazards, time series, atmospheric delay, monitoring
- NIGERIASAT-X PRODUCT STANDARDIZATION AND ECONOMIC BENEFITS
Sanusi Muhammad*, Oludare O. Mabogunje, Baslem M. Okehie and Joel O. Ayankale
Centre for Satellite Technology Development
Airport Road, Abuja
ABSTRACT: Nigeriasat-x is an advanced disaster monitoring micro-satellite carrying a multi-spectral earth observation payload with 22m Ground Sample Distance (GSD) capability. The satellite was designed and built by Nigerian Engineers to capture and provide images of the globe surface for social and economic benefits. A satellite image standardization and validity is subject to the restoration of its sensors and platform defects including such artifacts from communication and environmental influences. The requirements for image rectification and standardization is specific to the satellite platform, it’s sensor model and intended applications. In this paper, the nigeriasat-x requirements for the validation and restoration of its image product to obtain a standard and valid data for it’s proposed applications usage are discussed. Hence, algorithms that can be used to rectify and restore the nigeriasat-x image product are proposed. A satellite data provide a level of image detail for application usage depending on it’s sensor capability. In this research work, the nigeriasat-x sensor capability in providing beneficial applications for economic and social growth are investigated and discussed.
Keywords: nigeriasat-x, processing, standard, applications
- DEVELOPMENT OF A HYBRID GENETIC/K-MEANS ALGORITHM FOR ROUTE OPTIMIZATION CASE STUDY: UNMANNED AERIAL VEHICLE (UAV)
1C. M. Akachukwu, 2A. M. Aibinu, 3M. N. Nwohu and 4H. Bello Salau
1Centre for Satellite Technology Development, National Space Research and Development Agency,
Obasanjo Space Centre, Airport Road, Pyakassa Junction, Lugbe Abuja, FCT, Nigeria.
2, 4Department of Telecommunication Engineering, 3Department of Electrical Engineering,
Federal University of Technology, P.M.B. 65, Minna, Nigeria.
1chebeaka@gmail.com , {2abiodun.aibinu, 3nwohu, 4 habeeb.salau}@futminna.edu.ng
ABSTRACT: Unmanned Aerial Vehicles UAVs (aircraft without on-board human pilot) present a low budget platform for aerial applications like surveillance, land management and scientific research. There is a serious concern on achieving the necessary balance between the available on-board energy and the operational goals of range and endurance so as to meet up with mission requirements. This work is aimed at optimizing the performance of the UAV by minimizing the travel route in a multi-destination mission employing a hybrid of Genetic Algorithm (GA) and K-Means Algorithm. A novel hybrid K-Means/GA with polygamy selection and dynamic population control mechanism was presented for enhancing the GA selection process. Fitness values obtained from chromosomes in each generation were fed into the K-Means algorithm for selection-clustering process based on individual fitness value. The surviving chromosomes in the selected cluster underwent polygamy crossover mating process while the population of the offsprings which form the next generation were controlled by the dynamic population control mechanism. A MATLAB based graphical user interface (GUI) for UAV route optimization was developed and used to execute the performance evaluation of the developed algorithm. Simulation results obtained showed that the developed Genetic/K-means Algorithm can efficiently be used for UAV route optimization. The Hybrid GA/K-Means Technique was benchmarked with the GA-Roulette Wheel Selection Method. The result showed that the Hybrid GA/K-Means Technique greatly outperformed the GA-Roulette Wheel Selection Method.