The Greek philosopher Plato presented the Allegory of the Cave in his work The Republic. The allegory is related to Plato's Theory of Forms. The material world is known to us through sensation. Plato's Forms possess the highest and most fundamental kind of reality. In mathematical terms, we perceive the material world by means of remote sensing. For example, physicists see images in the bubble chamber, but not the elementary particles themselves. Geophysicists see seismic images, but not the underground earth itself. The received images correspond to Plato's shadows. Historically geophysicists used to look at the recorded seismic records without any processing at all. From their mental analysis, they ascribed a structure to the underground earth, but they would mistake appearance for reality. In 1952, digital signal processing (DSP) freed geophysicists from this practice. They could deconvolve the recorded seismic records and thereby obtained the true form of the underground structure of earth. They found Plato's reality. Deconvolution is now used in all fields of science.A person speaks into a mobile phone. It's DSP (Digital Signal Processing) chip deconvolves the speaker's voice. The deconvolved signal is transmitted and is received by the listener's phone. Its DSP chip re-convolves the signal thereby reproducing the speaker's voice.This book presents the basic elements of digital signal processing. It is self-contained. The chapters are 1. Review of mathematics; 2. Frequency; 3. Z-transform and frequency spectrum; 4. Convolution; 5. Wavelets; 6. FIR filters; 7. Deconvolution; 8. Crosscorrelation; 9. IIR filters; 10. Wavelet processing; and 11. Miscellaneous items. The book is suitable for colleges and for self-study.
About the Author: Enders Anthony Robinson is the Professor Emeritus of Geophysics in the Maurice Ewing and J. Lamar Worzel Chair at Columbia University in City of New York. He was born in Boston, Massachusetts on March 18, 1930. He received from MIT a SB in mathematics in 1950, a SM in economics in 1952 and a PhD in geophysics in 1954. In 1950 vast areas of the world, including great sedimentary basins and nearly all water-covered regions, were impervious to oil exploration because of intrinsic limitations in analog methods. In 1950-1954 Robinson at MIT, as a research assistant in mathematics and a research associate in geophysics, was the first to apply the methods of digital signal processing to the seismic records used in oil exploration. He used the Whirlwind digital computer at MIT and the Ferranti digital computer at the University of Toronto. His PhD thesis introduced the digital concept of deconvolution, which was successful in opening up every area of the world to oil exploration. The deconvolution process removed the unwanted reverberations that obscured the desired primary reflections. Robinson is a member of the National Academy of Engineering of the United States and a fellow of the European Academy of Sciences. In 2001, Robinson received the Maurice Ewing Gold Medal from the Society of Exploration Geophysicists with the citation, "For a lifetime of remarkable achievements that began while he was in MIT graduate school, when he in essence invented the field of digital seismic data processing. The progress in our science over the last 50 years in large part has evolved from the work of Enders Robinson." In 2003, the European Academy of Sciences awarded Robinson the Blaise Pascal Medal for Science and Technology as "the father of digital geophysics." In 2005, the International Astronomical Union, which acts as the internationally recognized authority for assigning designations to celestial bodies, named the asteroid Svenders with the citation, "In 1952 Enders Robinson became the first ever to perform signal processing on a digital computer." In 2010, the European Association of Geoscientists and Engineers awarded the Desiderius Erasmus Award to Robinson with the citation, "His early research laid the groundwork for seismic deconvolution and the widespread use of geophysical digital filters in general. Universally recognized as an eminent scientist, Dr. Robinson has aptly been described as one of the living legends of exploration geophysics."