A magnetic survey of an archeological site would need to contend with the fact that the earth's main magnetic field is changing randomly through time while the survey is being done. Here we examine the most basic low-cut filter. Integrate, actually to do a leaky integration, to deconvolve with where numerically, is slightly less than unity. The convolution ensures that the zero frequency is removed. Adjusting the numerical value of adjusts the cutoff frequency of the filter.
Seismological data is more complex.
Thus, in seismology, data space is higher dimensional. We will do more with multidimensional data in later chapters. Put Galilee data on a coarse mesh. Find the value of for which H is the most pleasing filter. Find the value of for which is the most pleasing filter.