nan Hossam-E-Haider

Analysis of DOP and its preciseness in GNSS position estimation

Accurate positioning of objects is important for navigation applications which gives rise to many interesting and challenging mathematical problems. These problems involve the relationship between positioning accuracy and satellite geometry in accordance to the users position. Dilution of precision is an indicator of satellite geometry for constellation of satellites used to determine a position. Better the geometry, better the position accuracy. DOP describes the geometric strength of the visible satellites configuration on the GPS accuracy. Ideally, the visible satellites should be located at wide angles relative to each other. The geometry of such satellite configuration is said to be strong and the DOP values are low.GPS signals from small region of sky gives larger DOP values, and position accuracy will suffer. If we accept lower elevation mask angle, several more satellites are available and DOP values drop to about its ideal value. The main motivation for this work is to introduce with the concept of DOPs: GDOP, PDOP, HDOP, VDOP, TDOP and to derive a comparative conclusion on DOP among GPS, Galileo and combined GPS - Galileo satellite configuration.

Comparative analysis of GNSS reliability: GPS, GALILEO and combined GPS-GALILEO

Global navigation satellite systems (GNSS) is the collective term for those navigation systems that provide the user with a three-dimensional positioning solution by passive ranging using radio signals transmitted by satellites. The most well known is the Navigation by Satellite Ranging and Timing (NAVSTAR) Global Positioning System (GPS). It is the most advanced but still not free from erroneous positioning and needs better accuracy. Now European GALILEO is under development, which is interoperable with GPS. In this paper performance of GPS and GALILEO alone and combined GPS-GALILEO system has been analyzed. Simulation has also done using duel and triple frequency. This paper has also presented which system and combination gives better precision and reliability. Also a time analysis of getting highest availability is studied. Results show that the improvement of the combined system is as high as 50% as present GPS alone system.

Feasibility study of GSM network for tracking low altitude helicopter

Low altitude helicopters are difficult to track due to the limitation of radar horizon, which may cause severe flight hazard. Thus, tracking of helicopter in real time is vital. There are various ways to track low flying helicopter, such as aircraft to ground data link, satellite phone etc. But the Global System for Mobile Communications (GSM) network has not been reported to be utilized yet to transmit the position information obtained from Global Navigation Satellite System (GNSS) receiver. A study was carried out to check the coverage of GSM network in low altitude for the feasibility of sending location information and the report has been presented in this paper. A GPS and GSM modem was programmed to log the time, location, altitude and signal strength. Two missions were carried out at 1000 feet with the device. Logged data were later on downloaded in a computer to analyze the low altitude coverage of the GSM network. The results show that the signal quality of the GSM was available for more than 75% of the time for sending SMS. Thus, it is evident from the study report that the low altitude helicopter can be tracked using GSM network.

Forecasting the long term energy demand of Bangladesh using SPSS from 2011–2040

Energy consumption is promptly increasing in most developing countries since they foster their economic growth. Modern technological electrical devices in day to day activities require high consumption of energy. Peoples requirement for higher living standard and rapid population growth are among the determinants in the growth of energy consumption. For optimal use of facility systems and power sources forecasting energy consumption is very important. This paper portrays the forecast of long term energy demand of Bangladesh as dependent variable and independent variables are GDP per capita, price of oil, population growth and lagged electricity consumption. The findings are similar and correspond with the assumptions in the relationship between variables.

A low cost MEMS and complementary filter based attitude heading reference system (AHRS) for low speed aircraft

AHRS is an important system that provides the 3-dimensional orientation (roll, pitch and yaw or heading) of an aircraft from which the flying performance can be evaluated. The avionics of aircraft are very sophisticated and majority of them do not allow any external interface for logging. As such, a standalone external AHRS is needed which should be comprised of low cost devices so that it becomes affordable for other aircrafts. This paper proposes a low cost Micro-Electrical-Mechanical system (MEMS) based AHRS for low speed aircraft to evaluate the flying performance. MEMS based 3-axis accelerometer, gyroscope and magnetometer have been used to build the AHRS. Low cost MEMS based sensors suffer from bias, drift and sudden spike. Low pass filter has been utilized to reduce the spikes. Complementary filter has been used to pin down the drift of the gyroscope from accelerometer reading. The system has been implemented in Arduino environment. Simulation and real time results have shown correct functioning of the system. Besides using as an AHRS in low speed aircraft, the system can be used for control and stabilization of other real time system.

Analyses of different types of errors for better precision in GNSS

World is moving forward and getting brighter future day by day because of the technological advancement. Each creation of innovation has its own particular importance. Global Navigation Satellite System (GNSS) is such an innovation which is playing a vital role. The most important components are Global Positioning System (GPS) and Galileo but some other systems are also mentioned like GLONASS, BEIDOU and QZSS (quasi-zenith satellite system). While a satellite orbiting about 12,551 miles above the earth surface transmitting a signal must have some errors. For better accuracy, errors must be minimized to an optimum level. The most common errors that affect GNSS receivers have been studied in this paper. After knowing each system, the main sources of errors and how they affect the quality of precision of the receiver can be determined which will lead to attain better performance.

Design and implementation of maximum power point tracking solar charge controller

Solar or photovoltaic (PV) system is an alternative clean energy resource that has received much attention in the research and industries. Solar charge controller (CC) is the heart of a solar system. Three common types of charge controller are ON/Off, pulse width modulation (PWM) and maximum power point tracking (MPPT). MPPT is getting very much popularity nowadays for its high capability of power extracting from solar panel. This paper is presenting here an improved design of MPPT solar charge controller using Aurduino. The proposed technique significantly reduce system power loss and increase the efficiency. Experimented highest efficiency 97.75% is recorded from the proposed system. Additionally, some new features are added like smart device charging, wireless data logging and protections from high voltage disconnect (HVD), low voltage disconnect (LVD), over current protection, short circuit protection and reverse polarity protection.

Performance analysis of optimal even bit triangular Quadrature Amplitude Modulation

The technique of adaptive modulation adjusts constellation points for Quadrature Amplitude Modulation (QAM) depending on channel conditions. Standard modulation schemes are not considered a good candidate for adaptive modulation due to inherent power inefficiency. In this paper, we propose an optimum constellation for transmission of even bits. This technique makes use of triangle quadrature amplitude modulation (TQAMs) to improve transmission efficiency for. Transmission efficiency calculations have been shown in detail. Simulations have also shown an improvement in the SER and BER of the proposed QAM modulation scheme.

Comparison of DOP of GPS and Galileo in the South Asian region

Dilution of precision is one of the most important parameter to consider for satellite navigation. With the existent full operational US operated GPS system the position can be calculated anywhere in the world. The upcoming European Galileo system is also a strong contender for the efficient calculation of position determination. Comparing both the GPS and Galileo in terms of GDOP and PDOP and also number of visible satellites the Galileo system has been proved a better version between the two. Simulation with the help of MATLAB GUI the overall comparison has been carried out for the three countries of South Asian region.