An Improved SFCW-GPR B-Scan Feature Enhancement Method for Underground Target Positioning Error Suppressing

Ground penetrating radar (GPR) is an effective tool for quickly identifying and locating underground targets by utilizing the reflection and scattering of electromagnetic waves at media discontinuities. However, for underground targets, there is a lot of background clutter surrounding them. Clutter will cover echoes reflected from underground targets, which makes it difficult to accurately detect the location of the targets. Thus, we propose an improved B-scan feature enhancement method based on a denoising source separation (DSS) algorithm. In addition, considering that the Cramer-Rao lower bound (CRLB) is the lowest achievable variance on an unbiased estimate, we evaluate the performance of the improved method and the classical method by calculating the CRLB of step frequency continuous wave (SFCW) GPR for the first time. We find that the CRLB of the midpoint position generated by the improved method is lower than that of the classical method, which means that the measurement accuracy of the improved method has a higher theoretical limitation.