About the Service
The CopPhil Ground Motion Monitoring Service (GMS) provides actionable ground deformation data across Philippine national territory, supporting applications in hazard monitoring, disaster risk reduction, and spatial planning. Applying Interferometric Synthetic Aperture Radar (InSAR) techniques, including Small Baseline Subset (SBAS) and Persistent Scatterer Interferometry (PSI), to Copernicus Sentinel-1 data, the service detects millimetre-scale land movement such as subsidence, seismic deformation, and land displacement. These results help partner agencies identify where ground movement is accelerating, which communities or assets may be exposed, and where preventive action is needed first.
Basic Product
The GMS Basic Product consists of maps showing the rate at which the ground is moving toward or away from the satellite, generated from two different viewing angles (ascending and descending orbits). Each measurement point includes its precise location and an indicator of data reliability. Movement is measured relative to a stable local reference point, allowing meaningful comparison across an area. As the foundational layer of the service, the Basic Product provides consistent coverage across most of the Philippines and supports initial identification of areas where ground movement may warrant closer attention.
Calibrated Product
The Calibrated Product builds on the Basic Product by comparing the ground motion maps against reference data from Global Navigation Satellite System (GNSS) stations. This step removes systematic errors present in radar measurements, producing velocity estimates which more accurately reflect actual ground movement. For applications requiring precise measurements, such as monitoring key infrastructure or tracking gradual deformation in high-risk areas, the Calibrated Product provides a meaningfully higher level of reliability.
Ortho Product
The Ortho Product combines measurements from two satellite passes (ascending and descending) to produce maps of ground movement broken down into two directional components: horizontal East-West and vertical Up-Down displacement. When the Calibrated Product is available, it serves as the input; otherwise, the corresponding Basic Product is used. By separating vertical from horizontal movement, the product allows users to distinguish between ground sinking and lateral shifting, which is particularly useful for interpreting the behaviour of slopes, fault zones, and urban areas subject to differential settling.
