Scholarly record
A MULTI-CRITERI METHODOLOGY FOR OPTIMAL CORNER REFLECTOR DEPLOYMENT USING INSAR COHERENCE, LAND USE, AND TERRAIN SLOPE: A CASE STUDUY OF THE PAUTE INTEGRAL HYDROPOWER COMPLEX (ECUADOR)
Abstract
The application of C-band InSAR techniques over densely vegetated areas faces critical limitations due to rapid temporal decorrelation, which requires the deployment of corner reflectors (CR) to ensure stable control points. In this context, traditional site selection criteria are often empirical and tend to overlook the spatiotemporal variability of interferometric coherence. In this study, a multicriteria methodology based on a spatial decision-making framework is proposed to optimize the selection of corner reflector installation sites and to define suitable reflector characteristics for the study area, including material selection and dimensions. The model integrates a multitemporal interferometric coherence analysis (2017–2024), processed through a Preliminary Priority Index (PPI), together with geophysical variables such as topographic slope and land use. Through a hierarchical weighting scheme grounded in DInSAR monitoring requirements, radiometric stability is prioritized as the determining factor over physical installation constraints. The methodology was applied at the Paute Integral Hydroelectric Complex, Ecuador, generating suitability maps for both ascending and descending Sentinel-1 acquisition geometries. The results demonstrate that this approach reduces uncertainty in site selection in complex terrains, enhances the persistence of control points, and enables the implementation of CR with appropriately defined characteristics, optimizing logistical effort and resource allocation in large-scale monitoring projects. Furthermore, the installation of corner reflectors improved interferometric coherence by more than 50% on average, contributing to increased reliability in deformation monitoring and supporting the effectiveness of the proposed site selection methodology.
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References7
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