The NASA-ISRO Synthetic Aperture Radar (NISAR) L-band SAR instrument employs multiple digital channels to optimize resolution while keeping a large swath on a single pass. High-speed digitization with fine synchronization and digital beam forming are necessary in order to facilitate this new technique called SweepSAR. An architecture employing multiple FPGA based digital signal processors has been conceived to facilitate digital calibration on an individual channel basis as well as digital signal processing to optimize the receive signal. On-board processing and data compression has been implemented to reduce the volume of data in order to satisfy the operational requirements of near global coverage for the desired science targets. A novel command and timing architecture was developed to manage this complex system to meet the challenging project requirements. The NISAR L-band Digital Electronics Subsystem is the combination of the hardware, firmware and software components architected and implemented to operate this radar and return the desired quantity and quality of data for the science community.
Ground-Based Inteferometric Synthetic Aperture Radar (GB-SAR) systems are popular remote sensing instruments able to provide radar images and to detect small displacements at great distance. Their working principle is based on the synthesis of a large aperture by exploiting the movement of a radar head along a linear mechanical guide. Recently a rotating antenna GB-SAR, named RotoSAR, has been proposed by the Author of this paper. The basic idea is to exploit the movement of a radar head fixed at a rotating arm, as a sort of windmill, to synthesize a large aperture. The aim of this paper is to explore the polarimetric capability of this novel radar configuration.
Multifunction phased array radar (MPAR) is a multiagency initiative to investigate the feasibility of replacing the aircraft surveillance and weather radar fleets in the US with a network of phased array radars based on a single, scalable architecture. The Federal Aviation Administration and the National Atmospheric and Oceanic Administration have been collaborating on MPAR risk reduction, which focuses on reducing cost, ensuring that the technology could accomplish all the missions within radar timelines, and developing dual polarization (dual pol) capability. The agencies have completed siting, cost, spectrum, dual pol, and back end studies, among others; have developed three dual pol architectures; and are building operational arrays to demonstrate that the technology can meet the basic needs of the agencies.
