b'A Sliding Doors momentFeature(then still called First Class of the Institute) on August 11, 1814. Indigital \x1dlters. The Fast Fourier Transform (FFT) and the spectral full form the theorem was given in 1825. The 1825 paper is seen bymethod for signal processing and analysis also came out of this many as Cauchys most important contribution to mathematics. period. Hamming wrote an excellent book on digital \x1dltering that summarises the applications and theory involved, with strengths However, Cauchy was also the \x1drst to prove Taylors theorem and weaknesses identi\x1ded. It includes a chapter on di\x1eerentiation, rigorously, establishing his well-known form of the remainder.and the Finite Impact Response \x1dlter (FIR) and its application.He also gave us the current form and notation for tensors.Hammings \x1dnite impact response \x1dlterUntil now, this story has had little relevance to members of the ASEG! The history of modern airborne geophysics in Australia started during World War II, with survey instruments developed for submarine detection. Analog charts were used to plot the readings along lines, and then there was a search for anomaly blips.The Manhattan projects chief mathematician, Richard Wesley Hamming, also worked on signal processing algorithms during World War II. After the war he joined Claude E. Shannon at Bell Laboratories, where in the 1950s and 1960s he invented Hamming codes that were used in telecommunications but have subsequently found general use.The front cover of Hammings book on digital \x1dltering.The computer languages Algol, Cobol, and Fortran dominated the scene, and vendors such as ICL, IBM, and CDC were dominant.Gunn and the MAGMAGE ProjectDespite this timeline, exploration geophysics only came to this FFT work in 1965, when Bhattacharyya \x1drst published. This was followed by Peter Gunn in mid-1976, when he published his seminal paper on linear transforms of gravity and magnetic \x1deld in Geophysical Prospecting.Richard HammingRichard Hamming was at Bell Laboratories, about the same time as modern computer languages and operating systems were being imagined.The distinctive logo of Bell LaboratoriesExploration geophysics, as we understand it, arguably emerged only after World War II. Geophysicists started by using very basic physics, and higher mathematics was mostly ignored. In terms of early-stage signal processing Hammings codes and direct descendants were copied and adopted. Hamming concentratedPeter Gunnon the problem of helping remove the crackle from audio signals in telephony. This was also the transition time from using analogIn discussions I have had with Peter, he tells how hard it was hardware \x1dlters, which used resistors and capacitors, to modernto take Bhattacharyyas work and apply it to real survey data. 33 PREVIEW JUNE 2023'