Lunar Topography: Global Determination by Radar: Delay-Doppler stereoscopy and radar interferometry yield high-resolution three-dimensional views of the moon
Previous methods used for two-dimensional radar mapping of the moon are contrasted with new techniques that add altitude information to the radar map. Delay-Doppler stereoscopy and delay-Doppler interferometry are shown to provide surface-height variations with higher accuracy and better global fidelity than has been possible previously. Sample results are presented for altitude contours on the moon as obtained with the Haystack and Westford radar systems of the Massachusetts Institute of Technology. An appendix describes the mathematical principles of delay-Doppler interferometry in determining the position of an arbitrary reflecting region of the lunar surface from measurements of the time delay, Doppler shift, and fringe phase of radar echoes from that region.
We study rogue waves in a graded-index planar waveguide with oscillating refractive index. We find that an additional refractive index can be used to manipulate the trajectory of the rogue wave without changing its shape evolution characters. The density distribution profile of rogue wave with the highest peak can be kept well through manipulating the graded-index term and nonlinear coefficient. Furthermore, the trajectories of these nonautonomous rogue waves still look like an “X” shape. These results provide possibilities to manipulate rogue wave in nonautonomous nonlinear systems.