L-Band Radar Interferometry for Monitoring Boreal Forest Dynamics with an Extreme Temporal Baseline

This study demonstrates the feasibility of using L-band two-pass Differential Interferometric Synthetic Aperture Radar (DInSAR) for monitoring boreal forest height dynamics with ALOS-2 PALSAR-2 data featuring an extremely long temporal baseline (2114 days). Scattering phase center despite the challenge of temporal decorrelation, high-quality interferometric measurements were achieved through careful selection of an interferometric pair with exceptionally similar atmospheric and forest–ground surface conditions. Validation against reference data confirmed that the resulting scattering phase center displacement map reflects real physical processes (height decrease due to logging and height increase due to growth) rather than decorrelation noise. The results prove the practical applicability of multi-temporal DInSAR pairs for monitoring changes in forest ecosystems.