Seasonal Analysis of Polarimetric Responses Utilizing Ku-Band GB-SAR Time Series Data

This study evaluated the seasonal dynamics of H/alpha<overline> target decomposition parameters derived from the spatially and temporally averaged coherence matrix of fully polarimetric Ku-band GB-SAR time series data over a one-year analysis period across three distinct land cover types in a residential area in Hokkaido, Japan. Overall, mean values of H-spatial/alpha<overline>(spatial) and H-temp/alpha<overline>(temp) parameters were identified across different H/alpha<overline> 2 D space zones for each land cover type, indicating that they exhibited a specific characteristic associated with their scattering mechanism. Subsequently, seasonal changes were observed to shift their seasonal mean values, with the transitions occurring within the same H/alpha<overline> 2 D space zone for the built-up land cover type. As for tree land cover type, zonal alterations were more prevalent in H-spatial/alpha<overline>(spatial) than in H-temp/alpha<overline>(temp) for each seasonal transition. However, only the H-spatial/alpha<overline>(spatial) seasonal mean values for the shrub land cover type demonstrated zone changes. Afterward, correlations between precipitation and H-spatial/alpha<overline>(spatial) parameters were more pronounced in vegetated-related land cover types than in man-made ones. Meanwhile, snowfall had stronger relationships with built-up and tree areas, whereas shrub areas showed weaker correlations. Concurrently, statistically significant positive correlations were identified between H-temp and precipitation across all land cover types. Nevertheless, the alpha<overline>(temp) yielded mixed results. For snowfall, built-up areas demonstrated more pronounced responses than trees and shrubs. Finally, outputs of this work could enhance knowledge of the underexplored yet compelling implementation of Ku-band GB-SAR time series data for continuous land cover monitoring activities.