Stripmap mode SAR raw data generator for ocean scene with large squint angle
A procedure for synthetic aperture radar (SAR) raw data generation for time-variant ocean surface is proposed. The appropriate ocean reflectivity function that takes account of the electromagnetic-ocean wave interaction is transformed on to SAR raw signal based on the distributed surface (DS) model. An efficient and accurate simulation algorithm with time-domain integration along range dimension for squint SAR raw signal is adopted. Moreover, the ocean's dynamics is accounted by means of interpolation based on the dispersion relationship of the time-variant waves. Simulation results are presented to demonstrate the validity and applicability of the proposed techniques.
On ocean SAR raw signal simulation
Simulation of synthetic aperture radar (SAR) raw signal pertaining to an ocean scene is presented. It embodies the distributed surface model, the hydrodynamic modulation, and the Bragg dominant scattering mechanism. Simulation experiments are provided.
Low-temperature thermal expansion of PEEK, HTA and some of their composites reinforced with carbon fibres
Abstract The thermal expansion of poly(ether ether ketone), a modification of poly (ether sulphone) and carbon fibre reinforced composites of these polymers has been measured over the range −153 to 27°C with a push-rod diameter. Where other measurements are available for comparison, agreement is obtained within experimental scatter. Some multidirectional composites are tested and the measured values of thermal expansion are explained qualitatively. It is thought that the specimen size has had a significant effect on these results. The longitudinal and transverse coefficients of thermal expansion of Hercules AS4 fibre have been calculated.