Design and Implementation of a Multi-Band Active Radar Calibrator for SAR

Abstract

Over the past decade, IECAS (Institute of Electronics, Chinese Academy of Sciences) has developed a set of L-, S-, C-, and X-band active radar calibrators that are deployed during the calibration campaigns for HJ1C synthetic aperture radar (SAR), Gaofen-3 SAR, and so on. In the near future, P-band and Ka-band spaceborne SARs will be launched. We found that it is not convenient to develop special active radar calibrators (ARCs) for a specific SAR or a specific frequency band SAR, and the acquired experience could help in the design and development of a multi-band ARC. This paper describes the design and implementation of a multi-band active radar calibrator which can operate in the L-, C-, X-, and Ka-bands. Moreover, laboratory measurements are performed to characterize the performance of the multi-band ARC, paying particular attention to the gain stability, the system transfer function, the gain flatness, and the linearity of the ARC receiver. Three such ARCs are developed, and to our knowledge, the multi-band ARC is the first of its kind in China or even in the world, and it can be used to implement the calibration campaigns of the Chinese Gaofen-3 SAR, Shenzhen-1 SAR, Luojia-2 SAR, and so on.

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

“…These systems have been introduced since the 1990s for SAR system calibration [ 13 , 14 , 15 , 16 ], and the interest was renewed when data from spaceborne radar for Earth Observations became available to researchers and users [ 17 , 18 ]. Nevertheless, only in the last decade did the idea to provide commercial ARs to use in spaceborne SAR applications spread [ 19 , 20 , 21 ], and the application extended for spaceborne SAR, working at different bands [ 22 ]. With respect to a PCR, an AR is smaller and lighter, but its reliability is often reduced by the need of a power source, usually a battery buffered by solar panels, and its phase stability demands careful design.…”

The capability of Sentinel-1 polarization combinations for oil spill detection (study case: Karawang, Indonesia)

“…Polarization mode in SAR images provides several types such as singlepolarization (HH or VV), dual-polarization (HH+HV or VV+VH), and multi-polarization (HH+HV+VH+VV) [2]. In addition, SAR images also have different wavelengths and are referred to as 1109 (2022) 012078 IOP Publishing doi:10.1088/1755-1315/1109/1/012078 2 bands such as L (390 -1550 MHz), C (3.900 -6.200 MHz), dan X (6.200 -10.900) [1], [3]. The SAR missions that have been operating for the earth observation are ALOS/PALSAR (2005, L band), TerraSAR-X (2007, X band) RADARSAT 3 (2009, C band), TanDEM-X (2010, X band), Sentinel-1 (2014, C band) [4].…”