A Low-Cost Active Reflector for Interferometric Monitoring Based on Sentinel-1 SAR Images

Abstract

The effectiveness of radar interferometric techniques in non-urban areas can often be compromised due to the lack of stable natural targets. This drawback can be partially compensated through the installation of reference targets, characterized by a bright and stable radar response. The installation of passive corner reflectors (PCR) often represents a valid aid, but these objects are usually cumbersome, and suffer from severe weather conditions; furthermore, the installation of a PCR can be difficult and costly, especially in places with hard accessibility. Active reflectors (AR) represent a less cumbersome alternative to PCRs, while still providing a stable phase response. This paper describes the design, implementation, and test of an AR prototype, designed to operate with the Sentinel-1 synthetic aperture radar (SAR), aimed at providing a fair performance/cost benefit. These characteristics, obtained through a tradeoff between the use of off-the-shelf components and a simple architecture, can make the setup of a dense network (i.e., tens of devices) in the monitored areas feasible. The paper reports the design, implementation, and the analysis of different tests carried out in a laboratory, and in a real condition in the field, to illustrate AR reliability and estimate its phase stability.

On the Efficacy of Compact Radar Transponders for InSAR Geodesy: Results of Multiyear Field Tests

“…The results from repeated levelling measurements between the concrete slabs carrying the reflectors exclude an actual displacement as a potential cause of the seasonal signal. Therefore, the phase measurements of the transponders are indeed sensitive to the temperature variations, with a typical dependency of 0.07-0.15 mm/ • C. This phase sensitivity to temperature was also observed for other compact transponder prototypes by [23], with a correlation coefficient of 0.8.…”

Active Reflectors for Interferometric Sar Deformation Measurement

“…This section briefly describes the AR developed and implemented at CTTC. A more technical description is provided in Luzi et al (2021). The designed AR consists of two antennas and an amplifying section, powered by a battery or any other available power source.…”

El Proyecto Mompa: Protocolos De Actuación Basados en El Monitoreo Mediante Interferometría Satelital Radar (Insar)

“…Por este motivo, y por el alto interés de la zona, se ha elegido instalar nueve reflectores artificiales (ocho pasivos y uno activo, Figs. 5 y 6) que aseguran una reflexión estable de la signar radar permitiendo obtener medidas de movimientos (Crosetto et al 2013;Luzi et al 2021). La primera instalación de la red de reflectores se finalizó el 1 de diciembre de 2020 gracias al apoyo de las administraciones locales.…”