On the use of contrast stretch and adaptive filter to enhance ground penetrating radar imagery

We propose using an adaptive filter to enhance ground penetrating radar (GPR) images. It is well known that GPR images are usually dominated by the specular ground reflection. The specular reflection makes the object scattered signals difficult to observe, so it first must be removed before more refined detection and classification processing can be employed. To remove the specular reflection, the biggest challenge is that, due to ground roughness, the reflection cannot be satisfactorily subtracted by some simple methods such as a moving-average filter. Using contrast stretch we can enhance the object reflect signal and then use standard background removal method to eliminate most of the specular reflection. During the contrast stretch, the GPR images may have "streaky" artifacts because of the background removal. To overcome this side-effect, we apply an adaptive filter to remove "streaky" artifacts. Using field data, we show that images of higher quality can be obtained by our method.