DeTeC  Demining Technology Center

GPR data analysis principles

Data files we have acquired in our sandbox using the SPRScan GPR from ERA Ltd

SEG-2 format specifications

MatLab routines used to process these data files

Data files we have acquired in Zagreb with our first prototype

DETEC-2 homepage, includes link to data acquired with our second prototype

VUB datasets (external link to data acquired in the Free University of Brussels (VUB) sandbox using the SPRScan GPR from ERA Ltd, after equipment transfer from the EPFL)

Links to GPR software related Web pages

One CD-ROM with all the data acquired in Cambodia, and one CD-ROM with all the data acquired in Europe (EPFL sandbox, Zagreb, etc.), are available to those who would like to do extensive data processing (a few individual files are more readily downloaded from these pages)

GPR data analysis principles

To perform data acquisition with our GPR system, the antenna (1GHz) consisting of a transmit and a receive antenna is moved along the surface of our sand box with one gantry. Response to the short electromagnetic pulses constantly emitted by the transmit antenna is recorded by the receive antenna. Changes in the electromagnetic impedance, due to the dielectric variations in the ground, alter the reflected or diffracted wave. Some of these changes can be associated with targets. Knowledge of the properties of the targets is very important to discriminate real targets from impostures.

Raw data are stored in files, respecting the SEG-2 standard format. One data file contains typically a sequence of A-scans, named B-scan or line-scan. This B-scan can be interpreted as an image of a vertical slice of the ground, on which hyperbolas indicate objets locations (Fig. 1, Swiss mine type Tret-Mi-59, 7 cm depth in sand).

The strong surface reflection makes the detection of objects just underneath the ground (typically the case of mines) particularly difficult. Simple 1-D filters (A-scan filtering) or more sophisticated 2-D filters (B-scan filtering) can be applied to suppress cluttering and increase the relevant information, i.e. the hyperbola shapes.
 

Links to GPR software related Web pages (obsolete - check the GPR bookmarks file instead)

Software from Earth Sciences at the University of Lausanne

Software from Geosciences at the University of Erlangen

GRADIX GPR processing and interpretation package for PC