Synthetic Aperture Radar (SAR) is a remote sensing technology finding applications in a wide range of fields, especially related to Earth observation. It enables a fine imaging that is crucial in critical activities, like environmental monitoring for natural resource management or disasters prevention. In this picture, the Scan-on-Receive (SCORE) paradigm allows for enhanced imaging capabilities thanks to wide swath observations at finer azimuthal resolution achieved by beamforming of multiple simultaneous antenna beams.
SPACEBEAM aims at designing, realizing and testing an innovative SCORE SAR receiver that will enable the concept of multiple beam SCORE for improved resolution.
In order to comply with the requirements of future swarms and constellations of low-Earth orbit satellites and cubesats in terms of performance, size, weight, power consumption and cost, the envisioned receiver will be based on an optical beamforming network realized as a photonic integrated circuit (PIC). The PIC will implement a precise, continuous beamforming of wideband RF received signals from an array of 12 antenna elements into 3 beams. At the same time, the PIC will also realize a frequency-agnostic photonic down-conversion of signals in the range from 5 to 40 GHz, so that the output signals can be directly digitized.
These innovative features make the SPACEBEAM PIC a powerful device for future Earth observation applications.
The PIC will be implemented using two materials platforms, to achieve a compact “hybrid” chip-assembly including several active and passive functions (lasers, detectors, modulators, filters, switches, delays, phase shifters). The PIC will be controlled using a novel actuation technique based on low-power consuming piezo elements. In order to push forward the maturity of the SPACEBEAM technology, the project will also develop and test a Space-compliant package for the PIC. The packaged PIC will be included in a specifically designed Engineering Model of the multi-beam SCORE-SAR sensor, to properly test the performance of the entire system.
The photonics-based SCORE SAR system will therefore show more functionalities, better performance, and lower size, weight, and power consumption than the current systems.
