According to the limitation of the satellite orbits and spectrum resources,this paper puts forward some methods for making effective use of the satellite orbits and spectrum resources.

With the rapid development of Wireless Local Area Network (WLAN), the valid spectrum resources are becoming more and more limited over time.

But at the same time wireless spectrum resource is in short supply day by day and the phenomenon of communication interfere is comparatively serious.

Influence of the observed-scene structure and noise on the precision of correlating Hartmann-Shack wavefront sensing is systematically analyzed,where the scene structure is described with spatial spectrum,and the signal-noise-ratio(SNR) is described with the ratio of the root-mean-square(RMS) of image grey variance to the root-mean-square of noise.

Often Misunderstandings arise that the spatial spectrum of a linear physical system of finite size is discrete and the spatial spectrum of a linear physical system of infinite size is continuous, i.

Based on the wave equation,we have developed the theory on harmonic generation of phase aberrated laser with nonuniform intensity profile by applying the spatial spectrum analysis to deal with the nonlinear coupling.

Imitated the optical system of Rowland circle structure, the Rowland sphere structure is built in this paper, the Rayleigh-Sommerfeld diffraction scalar integral formula of electromagnetic wave is simplified on the Rowland sphere structure, the computational formulas of spatial frequency spectrum and diffractional far field distribution from the weakly guiding optical fiber LP mode are derived.

The spatial frequency spectrum of intensity distribution on the focal plane is analyzed,which shows that the uniformity can be further improved by controlling the low frequency spatial modulations in the focal spot.

In this paper, the performance of the diffractive optical element (DOE) for beam smoothing is analyzed by using the spatial frequency spectrum.