Optical harness and receiver for future L-band radiometer

Abstract

ESA's Soil Moisture and Ocean Salinity (SMOS) mission was launched 2 Nov 2009 being the first ESA satellite relying on a complete optical harness (OHA), which was initially selected for the mechanical properties of optical fiber, what facilitated the deployment of the 3 arms of the instrument. In addition, other interesting advantages of the optical harness played an important role in the instrument performance such as lower propagation losses, immunity to electromagnetic interference, high bandwidth, SWaP reduction, etc. The two main functions of optical harness in SMOS were the distribution of reference clock and the transmission of the IQ data signals.Based on the good results obtained by SMOS-OPS mission, under the ESA ITI contracts No 4000120740/17/NL/AI and 4000122980/18/NL/IA, DAS Photonics, along with Airbus DS, and SENER Aeroespacial have developed the required OHA and the advanced L-band receivers (ALR), respectively, for a future advanced L-band radiometer mission with a target requirement of 10 km spatial resolution.In particular, two OHA configurations have been manufactured and tested. The first configuration aims at solving some identified issues as well as at improving performance of SMOS thanks to lessons learnt from the in-orbit operation, but without attempting novel techniques of calibration or signal distribution. The main goals of the second configuration, based on WDM techniques, are the improvement of the electrical performance and the optimization of the optical harness in terms of layout, i.e, to reduce number of cables/fibres, size, weight, as well as power consumption.

TriHex: Combining Formation Flying, General Circular Orbits, and Alias-Free Imaging, for High-Resolution L-Band Aperture Synthesis

“…The technology of TriHex is mostly based on the one used in SMOS, improved through technology activities ESA is, or has been, carrying out [33]: a 0.577λ envelope antenna [24], a dualfrequency advanced receiver [22] including a new RF ASIC [34], a multi-wavelength optical harness [35] and an advanced correlator unit with the built-in capability of filtering out Radio Frequency Interference [36].…”