tutorials:processing_gpr
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tutorials:processing_gpr [2019/07/22 05:50] – dominique | tutorials:processing_gpr [2019/07/25 10:44] (current) – [Examples] dominique | ||
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====== Processing GPR data with SU ====== | ====== Processing GPR data with SU ====== | ||
- | Yes ! It is possible to process GPR data wit SU to apply all the power of seismic processing tools to GPR data. | + | Yes ! It is possible to process GPR data wit SU to use all the power of seismic processing tools to GPR data. |
The basic trick is to fool SU by using micro second as the time unit and centimeter instead of meter. This way : | The basic trick is to fool SU by using micro second as the time unit and centimeter instead of meter. This way : | ||
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* For [[https:// | * For [[https:// | ||
- | * For [[https:// | + | * For [[https:// |
* For other manufacturers, | * For other manufacturers, | ||
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Compared to seismic data (apart from the recording or sampling time and size of the survey) GPR data exhibit a few differences. | Compared to seismic data (apart from the recording or sampling time and size of the survey) GPR data exhibit a few differences. | ||
- | * Absolute propagation time is generally unknown. Actually, GPR propagation is so fast that the receiver | + | * Absolute propagation time is generally unknown. Actually, GPR propagation is so fast that the receiver can' |
* GPR signal is generally strongly polarized and affected by some very low frequencies caused by electronic noise. This is easily corrected by removing the mean of the trace ('' | * GPR signal is generally strongly polarized and affected by some very low frequencies caused by electronic noise. This is easily corrected by removing the mean of the trace ('' | ||
* The direct wave in the air (even with shielded antennas) and in the ground is very strong. It often saturates the analog to digital converter. They must be muted prior applying bandpass filters. This can be done using '' | * The direct wave in the air (even with shielded antennas) and in the ground is very strong. It often saturates the analog to digital converter. They must be muted prior applying bandpass filters. This can be done using '' | ||
- | * The intrinsic attenuation of GPR signal is much faster (with respect to the wavelength) that for seismic signal and require the early application of a strong gain (with '' | + | * The intrinsic attenuation of GPR signal is much faster (with respect to the wavelength) that for seismic signal and require the early application of a strong gain (with '' |
==== Final processing ==== | ==== Final processing ==== | ||
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===== Examples ===== | ===== Examples ===== | ||
- | ==== 2D line in saturated limestone ==== | + | <WRAP center round todo 60%> |
- | This example comes from a ~38 m long 2D line above a dry limestone. It has been acquired using a MALÅ/RAMAC GPR, fitted with 250 MHz shielded antennas. Time sampling is 403 ps, number of samples is 1024, antenna separation is 36 cm (according to the config file), number of stacks is 128, number of traces is 188. | + | Later... Be patient ! |
+ | </ | ||
- | === Raw data === | ||
- | |||
- | --- // | ||
+ | --- // |
tutorials/processing_gpr.txt · Last modified: 2019/07/25 10:44 by dominique