Standard palettes for GPR data analysis

Most GPR profiles are displayed in point mode form. This gives an amplitude colour coded image(1) where waveform amplitudes are plotted according to predefined colours (forming a palette). They are similar in concept to early GPR hard copy products based on grey scale distributions but they provide greater flexibility and dynamic range for anomaly recognition. A wiggle mode trace can also be included as an overlay on the colour image to assist with wavelet recognition and enhance lateral correlations. However, more subtle components of the waveform (in particular phase relationships) are often ignored. Many data reduction, image display, and signal processing algorithms used for GPR surveys have been borrowed from remote sensing, seismic and general geophysical exploration techniques. However, they have been implemented in a relatively primitive form. In particular, the advantages of correct and relevant colour palette selection for point mode images have been ignored. More rational palettes are now proposed to convey amplitude features, in combination with phase information, for analysis of target properties.