Enhancing the vertical resolution of lunar penetrating radar data using predictive deconvolution

The Yutu-2 rover onboard the Chang’E-4 mission performed the first lunar penetrating radar detection on the farside of the Moon. The high-frequency channel presented us with many unprecedented details of the subsurface structures within a depth of approximately 50 m. However, it was still difficult to identify finer layers from the cluttered reflections and scattering waves. We applied deconvolution to improve the vertical resolution of the radar profile by extending the limited bandwidth associated with the emissive radar pulse. To overcome the challenges arising from the mixed-phase wavelets and the problematic amplification of noise, we performed predictive deconvolution to remove the minimum-phase components from the Chang’E-4 dataset, followed by a comprehensive phase rotation to rectify phase anomalies in the radar image. Subsequently, we implemented irreversible migration filtering to mitigate the noise and diminutive clutter echoes amplified by deconvolution. The processed data showed evident enhancement of the vertical resolution with a widened bandwidth in the frequency domain and better signal clarity in the time domain, providing us with more undisputed details of subsurface structures near the Chang’E-4 landing site.