Sun observations provide a robust way for determining the geodetic or true azimuth at a location. Azimuth is generally defined as the angle in the plane measured from the meridian’s north (or south) to the location of the line of interest. It is common to use the north azimuth; also referred to as “azimuth”, especially in civilian surveying applications. The astronomic meridian is obtained thro...

Azimuth modulation of the normalized radar crosssection in satellite data sets over Greenland is investigated. Data sets from the NASA Scatterometer (NSCAT) and from the European Remote Sensing Advanced Microwave Instrument (ERS) are employed. Azimuth dependence is clearly observed. The largest azimuth dependence occurs in the C-band ERS data with peak-to-peak azimuth modulations up to 3.0 dB. ...

We present a method to construct 3D angle gathers from extended images obtained using wave-equation migration. The method relies on an analytic formula that associates the reflection and azimuth angle to reflection kinematics in the images. The decomposition is able to render the angle gathers that characterize the reflectivity as a function of both reflection and azimuth angle simultaneously. ...

Common-image gathers are an important output of prestack depth migration. They provide information needed for velocity model building and amplitude and phase information for subsurface attribute interpretation. Conventionally, common-image gathers are computed using Kirchhoff migration on commonoffset/azimuth data volumes. When geologic structures are complex and strong contrasts exist in the v...

Extended common-image-point gathers (CIP) constructed by wide-azimuth TI wave-equation migration contain all the necessary information for angle decomposition as a function of the reflection and azimuth angles at selected locations in the subsurface. The reflection and azimuth angles are derived from the extended images using analytic relations between the space-lag and time-lag extensions. Thi...

A RF directional modulation technique using a switched antenna array is proposed for communication and direction-finding applications. The main idea is that a baseband modulation signal is transmitted by the switched antenna array. The phase center of the transmit signal is moved by the feeding line of each element from the left to the right. In this way, the data information and Doppler freque...

We study the mechanical property of a two-dimensional filament with constant spontaneous curvature and under uniaxial applied force. We derive the equation that governs the stable shape of the filament and obtain analytical solutions for the equation. We find that for a long filament with positive initial azimuth angle (the azimuth angle is the angle between x axis and the tangent of the filame...