Full text loading...
-
Characterization And In-Field Suppression Of Noise In Hydrogeophysics.
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 8th EEGS Symposium on the Application of Geophysics to Engineering and Environmental Problems, Apr 1995, cp-206-00033
Abstract
Present developements of hydrogeophysical methods provide us with hitherto unseen sampling density in profiling and<br>sounding. Transient electromagnetic sounding (TEM) data and pulled array continuous electrical profiling, PA-CEP<br>(Sorensen and Christensen, 1994) are among these. Common to these types of data is the possibility of simple stacking or<br>moving averaging to increase the signal to noise ratio due to the data redundency. Moreover, due to the volume of the raw<br>data the stacking must be done in the held. However, only for white Gaussian noise is simple stacking optimal. Studies have<br>shown that it is critical to characterize the noise with respect to frequency spectrum and statistical distribution as a design<br>basis for more adaptive noise suppression procedures in order to achieve reliable results.<br>Flexible stacking schemes for the data types are presented and we demonstrate their adaptation based on studies of the noise<br>characteristics for each type. Also, the special problems arising in online processing for the different stacking schemes are<br>addressed. The large data volume involved calls for in-field reduction of the data. This study is aimed at designing the online<br>processing required.