Airbus (Spain)

The burgeoning interest within the space community in digital beamforming is largely attributable to the superior flexibility that satellites with active antenna systems offer for a wide range of applications, notably in communication services. This paper delves into the analysis and practical implementation of a Digital Beamforming and Digital Down Conversion (DDC) chain, leveraging a high-speed Analog-to-Digital Converter (ADC) certified for space applications alongside a high-performance Field-Programmable Gate Array (FPGA). The proposed design strategy focuses on optimizing resource efficiency and minimizing power consumption by strategically sequencing the beamformer processor ahead of the complex down-conversion operation. This innovative approach entails the application of demodulation and low-pass filtering exclusively to the aggregated beam channel, culminating in a marked reduction in the requisite digital signal processing resources relative to traditional, more resource-intensive digital beamforming and DDC architectures. In the experimental validation, an evaluation board integrating a high-speed ADC and a FPGA was utilized. This setup facilitated the empirical validation of the design’s efficacy by applying various RF input signals to the digital beamforming receiver system. The ADC employed is capable of high-resolution signal processing, while the FPGA provides the necessary computational flexibility and speed for real-time digital signal processing tasks. The findings underscore the potential of this design to significantly enhance the efficiency and performance of digital beamforming systems in space applications.

This article presents the hybridization of a 3D full-wave Finite-Difference Time-Domain (FDTD) solver with a multilevel multiconductor transmission line (MTL) solver, using the circuit simulator ngspice to treat TL interconnections. This schema is intended to study the electromagnetic response of 3D systems where networks of shielded cables are present. The MTL solver can simulate networks of shielded cable bundles with arbitrary topology. Bundles interconnects and terminations are described using ngspice. Interaction between different levels in the bundle is described by means of the transfer impedance of the cable shields.

This paper presents a high-brightness LED (HB-LED) driver for visible light communication (VLC) based on two converters. The first is a high-frequency buck DC/DC converter and the second is a low-frequency boost DC/DC converter, connected in series with respect to the LED load and connected in parallel at the input, forming a series/parallel boost/buck DC/DC converter. It is well known that a VLC system needs to perform two different tasks: biasing the HB-LED load and transmitting the communication signal. These typically have different power requirements; the bias power is 75%, while the communication power is 25% of the total power. The requirements of each converter are also different; the communication signal requires a fast output response and, therefore, a high switching frequency, while the biasing control does not require a converter with a high output voltage response. The proposed architecture in this paper takes advantage of the differences between the two tasks and achieves high efficiency and high communication performance by means of splitting power between the two DC/DC converters. The high-frequency buck DC/DC converter tracks the communication signal, while the low-frequency boost DC/DC converter is responsible for lighting tasks. This technique enables high efficiency because most of the power is processed by the low-frequency converter, while a minor part of the power is processed by the high-frequency converter, achieving high communication performance. To provide experimental results, the proposed VLC HB-LED driver was built and validated by reproducing a 64-QAM with a bit rate up to 1.5 Mbps, reaching 91.5% overall efficiency.

Decarbonizing aviation is a critical goal for mitigating climate change, as the sector contributes significantly to global greenhouse gas emissions. Hybrid electric aircraft (HEA) represent a promising step towards reducing the environmental impact of aviation. The paper presents a review of life cycle assessment analysis of hybrid electric aircraft designs as emerging technologies. The literature review is complemented by a presentation of the technologies developed within the HECATE (Hybrid Electric Regional Aircraft Distribution Technologies) EU project. Results of HECATE prove that for the HEA platforms, requirement for higher voltage and higher power distribution components is essential to reduce the environmental load. All the literature findings show that hybrid-electric aircraft configurations can reduce the carbon intensity per RPK (revenue passenger kilometer) from 49%-57% in the conservative scenario to 82%-88% in the best scenario when compared to fossil-fueled aircraft. The environmental impact of HEA could be further reduced by 7% if electricity for batteries charging is produced from renewable sources and battery has longer lifetime. LCA analysis shows that the main contributors to the environmental load produced by HEA are aircraft airframes and batteries, producing on average 15-40 kg CO2 eq./h.

The Land Surface Temperature Monitoring (LSTM), part of the expansion missions of the Copernicus programme, aims at providing data for land surface temperature and evapotranspiration at unprecedented spatio-temporal resolution, with the main objective of providing valuable data for improved water management at individual European field scale. This paper gives an overview of the instrument main requirements flowing down from the mission objectives, and the instrument design selected to fulfill them. The technical challenges are described as well as the key performances.

Legacy Avionics systems, specifically those related to safety-critical functions of an aircraft, usually impose a series of constraints (tight-coupling of the hardware and software system elements, lost knowledge due to dissemination of engineering teams after project end, supplier-locked system documentation, obsolescence of development and enabling systems, etc.) that may hinder or even prevent their adaptation to new use cases or satisfying specific customer needs that were not part of the initial development.While system replacement could seem the obvious solution to these issues, that approach on safety-critical systems with multiple embedded functions imposes a heavy certification risk and may result in an unjustifiable business case due to the unnecessary scope increase.Our research has shown how to enlarge the scope of already-existing Display & Control (D&C) systems in military aircraft by interposing a new complementary system in-between the legacy systems using a man-in-the-middle approach. This new architectural concept [20] just focuses on the added-value control functions, transparently performing data blending from both ends and adapting certain streams of data as required so the end-systems and the final user remain unaware of the intruder. In this way, the certification of the legacy elements that still perform their intended function is not affected, while at the same time we are able to expand the system capabilities, reducing the technical development effort to an acceptable level.We have also shown how the research activities for such an innovative architectural concept continued into the development phase of a new flexible product portfolio that allowed Airbus Defence and Space to offer a new plethora of capabilities to our existing customers, covering their needs within an admissible framework of time, budget and technical performance.

The Land Surface Temperature Monitoring (LSTM), part of the expansion missions of the Copernicus programme, aims at providing data for land surface temperature and evapotranspiration at unprecedented spatio-temporal resolution, with the main objective of providing valuable data for improved water management at individual European field scale. This paper gives an overview of the instrument main requirements flowing down from the mission objectives, and the instrument design selected to fulfill them. The technical challenges are described as well as the preliminary predicted performances. Additional presentation content can be accessed on the supplemental content page.

ESA's Soil Moisture and Ocean Salinity mission, SMOS, in operation since November 2009, is producing global maps of soil moisture and sea surface salinity with an average resolution of 40 km. In the context of a future L-band mission, it is necessary to address the future needs for a range of applications over land and ocean that call for much enhanced spatial resolution, down to 1–10 km. With today's knowledge, the spatial resolution of a microwave radiometer can be improved only by increasing and reshaping its aperture size. In this context, this paper presents the Formation Flying L-Band Aperture Synthesis (FFLAS) mission concept which focuses on using formation flying in combination with aperture synthesis as a potential way to improve the spatial resolution significantly. Moreover FFLAS makes full use of all lessons learnt from SMOS in-orbit experience.