InSAR coherence based temporal changes detection and mapping of tropical forest and plantations in Northern Borneo

Abstract The TanDEM-X InSAR coherence data is cloud-free and not affected by temporal decorrelation. It also provides excellent interferometric data on the canopy, which is helpful for direct detection and mapping of the temporal changes in tropical forests and plantations. In this paper, three InSAR scenes were acquired for 2012, 2017, and 2019, all in single HH polarization and in bistatic mode covering northern Sabah. Generated coherence data was compared in pairwise of before and after scenarios using raster changes analysis. GIS analysis and temporal changes information extraction were done using the digitized forests and plantations land use boundaries. Results show Oil palm is mostly unchanged, and Industrial Tree Plantation (ITP) decreased by 27% between 2021-2017 and 17% between 2012-2019 due to ongoing timber harvesting. Meanwhile, Forest Reserve (FR) showed an increase of 14% between 2012-2017. The study demonstrated the potential of using TanDEM-X InSAR coherence for direct, quick, and simple tropical forest and plantation changes and mapping.