Propagation studies at 900 Mhz. For mobile radio.

Çiğiran, Veli


Propagation models for hilly terrain based on ray optic methods
Yıldırım, Erkan Ersin; Dural Ünver, Mevlüde Gülbin; Department of Electrical and Electronics Engineering (2015)
In RF propagation path loss modeling, numerical methods may not be useful since they require very long computation times because electrically very large objects may be located in the terrain. Ray optic methods such as Geometrical Optics (GO) or Geometrical Theory of Diffraction (GTD) are more commonly used in propagation problems as well as the empirical models. Although ray optics methods are designed for very high frequency applications, they provide quite accurate path loss estimations in hilly terrain i...
Scattering from perfectly conducting plane angular sectors.
Kahraman, Gökhan; İnan, Kemal; Department of Electrical and Electronics Engineering (1993)
Vibrationally Excited Satellite Atttiude Actuator A Feasibity Study
Tekinalp, Ozan; Azgın, Kıvanç (2015-06-16)
A new attitude control actuator, the vibrating mass gyroscope is considered. The actuator transforms the vibratory motion of a single gimbal gyroscope to a positive or negative, fluctuating control torque. The equations of motion for such an actuator are presented. The feasibility of construction of such an actuator is investigated. Possible means of realizing the vibratory motion is proposed.
Pulse timing studies of X-ray binaries: GX1+4,SWIFT J0513.4-6547, X Persei and SXP 1062
Serim, Muhammed Miraç; Baykal, Altan; İnam, Sıtkı Çağdaş; Department of Physics (2019)
This thesis focuses on X-ray timing properties of four different X-ray binary systems, based on archival data of the X-ray missions RXTE, Swift, XMM-Newton, Chandra and Integral. One of the selected sources is a LMXB system GX 1+4 while remaining sources are BeXB systems: SWIFT J0513.4-6547, X Persei and SXP 1062. For GX 1+4, the timing analysis of RXTE-PCA observations between 2001 March 3 and 2003 January 31 are presented. The timing solutions of two different time intervals are constructed. Futhermore, w...
Pulse frequency changes of 1E 2259+586 and the binary interpretation
Baykal, Altan (1996-03-20)
Pulse frequencies from the archival ROSAT observations of 1E 2259+586 are presented. A short-term spin-up episode superposed on the secular spin-down trend is observed. Combining the previously published pulse frequencies, we estimate the variance of the angular velocity over a 15 yr span of observations. The level of fluctuations in angular velocity is similar to that of established accreting binary neutron stars. These results favor accretion by a neutron star from a very low mass companion as the source ...
Citation Formats
V. Çiğiran, “Propagation studies at 900 Mhz. For mobile radio.,” Middle East Technical University, 1975.