Detection of Soil Moisture Variations Beneath an Asphalt Layer Using L-Band SAR

This dataset contains L-band synthetic aperture radar (SAR), interferometric SAR (InSAR), and in situ soil moisture measurements acquired during controlled experiments designed to investigate the detectability of subsurface soil moisture variations beneath asphalt cover. The experiments were conducted in a microwave anechoic chamber using a rail-mounted L-band Mini-SAR system operating at a center frequency of 1.5 GHz with a bandwidth of 400 MHz. The dataset includes measurements from two experimental stages. The first stage consists of corner-reflector observations acquired beneath asphalt layers with thicknesses of 1, 2, 3, 5, 6, 7, and 9 cm, together with a control observation obtained under a 9-cm-thick asphalt layer without a corner reflector. These data were collected to evaluate the attenuation of subsurface target echoes and the penetration detectability of the L-band Mini-SAR system through asphalt cover. The second stage consists of seven repeat-pass SAR acquisitions, denoted as L1–L7, collected during a controlled infiltration experiment beneath an approximately 9-cm-thick asphalt layer. The L1 acquisition was used as the reference image, whereas L2–L7 were used as secondary images to generate the multitemporal interferometric products. Soil volumetric water content was synchronously measured using time-domain reflectometry probes during the infiltration process. The archived files include the complex single-look complex data, SAR amplitude or backscattering intensity products, wrapped interferograms, unwrapped interferometric phase products, interferometric coherence maps, closure-phase products derived from multitemporal acquisition triplets, and cumulative closure-phase products. Synchronized soil volumetric water content measurements, experimental parameters, radar system parameters, and observation-geometry information are also provided where applicable. The dataset supports the analysis of microwave propagation and scattering through asphalt-covered layered media and the evaluation of SAR/InSAR responses to subsurface soil moisture variations. It can be reused to investigate interferometric phase sensitivity, coherence loss, phase nonclosure, backscattering variations, electromagnetic penetration models, and processing methods for subsurface moisture detection beneath engineered surface covers. These data support the research article entitled “Detection of Soil Moisture Variations Beneath an Asphalt Layer Using L-Band SAR.”