瞬时谱估计，用于检测低频油气特性，有助于地层油气识别。-Instantaneous spectrum estimation for detecting low-frequency oil and gas properties, help to identify the formation of oil and gas.

To fully utilize the character of the bioradar echo signal, autocorrelation analysis, spectral estimation methods and time-frequency analysis are presented in this paper. These methods are employed to deal with no one, single people and multi-people

Application of spread spectrum for satellite land mobile systems is difficult in satellite link because of synchronization and providing code or considerable Doppler shift. This is particularly high for LEO satellites. So that, a Doppler shift carr