A newer version of this dataset with data for 2015-2021 can be found in JAXA/ALOS/PALSAR/YEARLY/SAR_EPOCH The global 25m PALSAR/PALSAR-2 mosaic is a seamless global SAR image created by mosaicking strips of SAR imagery from PALSAR/PALSAR-2. For each year and location, the strip data were selected through visual inspection of the browse mosaics available over the period, with those showing minimum response to surface moisture preferentially used. In cases where the availability was limited (e.g., because of the requirement for observations during specific emergencies), data were necessarily selected from the year before or after, including from 2006. Shimada et al. 2014 There is no data for 2011-2014 due to the gap between ALOS and ALOS-2 temporal coverage. The SAR imagery was ortho-rectificatied and slope corrected using the 90m SRTM Digital Elevation Model. A destriping process (Shimada & Isoguchi, 2002, 2010) was applied to equalize the intensity differences between neighboring strips, occurring largely due to seasonal and daily differences in surface moisture conditions. Polarization data are stored as 16-bit digital numbers (DN). The DN values can be converted to gamma naught values in decibel unit (dB) using the following equation: γ₀ = 10log₁₀(DN²) - 83.0 dB Attention: Backscatter values may vary significantly from path to path over high latitude forest areas. This is due to the change of backscattering intensity caused by freezing trees in winter. More information is available in the provider's Dataset Description.

Uma versão mais recente desse conjunto de dados com dados de 2015 a 2021 pode ser encontrada em JAXA/ALOS/PALSAR/YEARLY/SAR_EPOCH. O mosaico global de 25 m do PALSAR/PALSAR-2 é uma imagem global de SAR contínua criada por faixas de mosaico de imagens de SAR do PALSAR/PALSAR-2. Para cada ano e local, os dados de faixa foram selecionados por inspeção visual do …