1. Fundamentals Introduction Seismic waves: Propagation Velocity and Amplitudes Seismogram Measurement systems Sources, receivers, Acquisition strategies Data processing “Pre-processing” Filter und Deconvolution Velocity analysis and Stacking Migration Interpretation Overview

2. Loading of the data/conversion Demultiplexing Editing Geometry Amplitude correction Frequency filter Deconvolution Velocity analysis NMO-Correction Stacking Migration Measurements Navigation Printing/storage CMP-Sorting Prestack Poststack Post-processing Pre-Processing Basic scheme of the seismic data processing

3. Frequency analysis  Analysis of the frequency content of the data  Difference in frequency content for interface waves, Noise and Reflections  In what frequency range are the reflections present ?

4. Outline  Periodic and transient waveforms  Fourier transformation time domain frequency domain  Frequency filters  Tapering  Field examples

5. ground-roll low freq. noise: high freq. Frequency content of a shot

6. Wavelength  v Period  Amplitude t Waves Velocity v ff = Period  1 f --- 2   ------== Wavenumber k ---= 2  Acos(2  ft) Acos(2  ft-  ) Phase 

7. Periodic and transient waveforms Periodic waveform Transient waveform

8. Periodic waveforms  Any periodic waveform, may be decomposed into a series of sine (or cosine) waves whose frequencies are integer multiples of the basic repetition frequency  It is necessary to define not only the frequency of each component, but also its amplitude and phase

9. Fourier transformation Fourier Transformation: Inverse Fourier Transformation:

10. Summation of different frequencies

11. Phase-Spectrum Amplitude-Spectrum g(t) G(f) = A(f) e i  (f) A(f)  (f) Fourier transformation where A(f)={[Real part of G(f)] 2 +[Imaginary part of G(f)] 2 } 1/2   (f)=tan -1 () real part of G(f)] imaginary part of G(f) Real part Imaginary part  (f) A(f)

12. frequency amplitude phase f1f1 f2f2 Sum: f1f1 f2f2

13. f1f1 f2f2 f1f1 f2f2

14. Digital representation of continuous amplitude and phase spectrum associated with a transient waveform

15. Spike function DC bias Transient waveforms approximating seismic pulses

17. Low Pass High Pass Band Pass Notch filter Frequency filter f ff f

18. Tapering

19. Tapering of filters  Butterworth  Hanning  Ormsby Amplitude and phase characteristics.

20. Band-pass filtered raw field records

21. Corrected for geometric spreading: frequency absorption remains