matlab codes for spatial domain filtering

空间数据扩边以后做fft并在频率域延拓，可用于求重磁异常-expansion of spatial data and FFT， in the frequency domain extension can be used to find the gravity and magnetic anomalies

Local image features or interest points provide compact and abstract representations of patterns in an image. In this paper, we propose to extend the notion of spatial interest points into the spatio-temporal domain and show how the resulting feature

用相位移加实现速度纵横向变化、复杂陡倾地质模型的正流模拟，为复杂波场的地震、地质解释提供了精确、实用的方法。一般情况下，相位移延拓方法对徒倾斜地层成像精度高、稳定性好、计算快，但实现速度的横向变化困难；而频率、空间域的有限差分法算法简单、稳定性好、能适应速度的纵横向任意变化，但偏移陡断地层存在很多问题-Using phase shift and realization of vertical velocity variations, complex flow simulation of stee