Spectral sizing of a coarse-spectral-resolution satellite sensor for XCO2

Verifying anthropogenic carbon dioxide (CO$_{2}$) emissions globally is essential to inform about the progress of institutional efforts to mitigate anthropogenic climate forcing. To monitor localized emission sources, spectroscopic satellite sensors have been proposed that operate on the CO$_{2}$ absorption bands in the shortwave-infrared (SWIR) spectral range with ground resolution as fine as a few tens of meters to about a hundred meters. When designing such sensors, fine ground resolution requires a trade-off towards coarse spectral resolution in order to achieve sufficient noise performance. Since fine ground resolution also implies limited ground coverage, such sensors are envisioned to fly in fleets of satellites, requiring low-cost and simple design, e.g., by restricting the spectrometer to a single spectral band. Here, we use measurements of the Greenhouse Gases Observing Satellite (GOSAT) to evaluate the spectral resolution and spectral band selection of a prospective satellite sensor with fine ground resolution. To this end, we degrade GOSAT SWIR spectra of the CO$_{2}$ bands at 1.6 (SWIR-1) and 2.0 μm (SWIR-2) to coarse spectral resolution, without a further addition of noise, and we evaluate single-band retrievals of the column-averaged dry-air mole fractions of CO$_{2}$ (XCO$_{2}$) by comparison to ground truth provided by the Total Carbon Column Observing Network (TCCON) and by comparison to global “native” GOSAT retrievals with native spectral resolution and spectral band selection. Coarsening spectral resolution from GOSAT’s native resolving power of > 20000 to the range of 700 to a few thousand makes the scatter of differences between the SWIR-1 and SWIR-2 retrievals and TCCON increase moderately. For resolving powers of 1200 (SWIR-1) and 1600 (SWIR-2), the scatter increases from 2.4 (native) to 3.0 ppm for SWIR-1 and 3.3 ppm for SWIR-2. Coarser spectral resolution yields only marginally worse performance than the native GOSAT configuration in terms of station-to-station variability and geophysical parameter correlations for the GOSAT–TCCON differences. Comparing the SWIR-1 and SWIR-2 configurations to native GOSAT retrievals on the global scale, however, reveals that the coarseresolution SWIR-1 and SWIR-2 configurations suffer from some spurious correlations with geophysical parameters that characterize the light-scattering properties of the scene such as particle amount, size, height and surface albedo. Overall, the SWIR-1 and SWIR-2 configurations with resolving powers of 1200 and 1600 show promising performance for future sensor design in terms of random error sources while residual errors induced by light scattering along the light path need to be investigated further. Due to the stronger CO$_{2}$ absorption bands in SWIR-2 than in SWIR-1, the former has the advantage that measurement noise propagates less into the retrieved XCO$_{2}$ and that some retrieval information on particle scattering properties is accessible

Rethinking Land in the Anthropocene: from Separation to Integration

Nur wenn sich unser Umgang mit Land grundlegend ändert, können die Klimaschutzziele erreicht, der dramatische Verlust der biologischen Vielfalt abgewendet und das globale Ernährungssystem nachhaltig gestaltet werden. Der WBGU schlägt fünf exemplarische Mehrgewinnstrategien vor, um Konkurrenzen zwischen Nutzungsansprüchen zu überwinden. Diese sollten durch fünf Governance-Strategien vorangetrieben werden, darunter insbesondere die Setzung geeigneter Rahmenbedingungen, eine Neuorientierung der EUPolitik und die Errichtung von Gemeinschaften gleichgesinnter Staaten.Only if there is a fundamental change in the way we manage land can we reach the targets of climate-change mitigation, avert the dramatic loss of biodiversity and make the global food system sustainable. The WBGU proposes five multiple-benefit strategies illustrating ways of overcoming competition between rival claims to the use of land. These should be promoted by five governance strategies, especially by setting suitable framework conditions, reorienting EU policy and establishing alliances of like-minded states

On the Availability and Effectiveness of Open Source Software for Digital Signing of PDF Documents

Part 3: Examples and Case StudiesInternational audienceDigital signatures are important in order to ensure the integrity and authenticity of information communicated over the Internet involving different stakeholders within and beyond the borders of different nations. The topic has gained increased interest in the European context and there is legislation and project initiatives aiming to facilitate use and standardisation of digital signatures. Open standards and open source implementations of open standards are important means for the interoperability and long-term maintenance of software systems implementing digital signatures. In this paper we report from a study aiming to establish the availability and effectiveness of software provided under an open source license for digital signing and validation of PDF documents. Specifically, we characterise the use of digital signatures in Swedish Governmental agencies, report on the interoperability of open source and proprietary licensed software for digital signatures in PDF documents, and establish the effectiveness of software provided under an open source license for validation of digital signatures in PDF documents

Towards a Reference Model on How to Utilise Open Standards in Open Source Projects: Experiences Based on Drupal

Part 2: Short PapersInternational audienceIt is known that standards implemented in Open Source software (OSS) can promote a competitive market, reduce the risk for lock-in and improve interoperability, whilst there is limited knowledge concerning the relationship between standards and their implementations in OSS. In this paper we report from an ongoing case study conducted in the context of the ORIOS (Open Source software Reference Implementations of Open Standards) project in which influences between OSS communities and software standard communities are investigated. The study focuses on the Drupal project and three of its implemented standards (RDFa, CMIS, and OpenID)

An Exploration of Openness in Hardware and Software Through Implementation of a RISC-V Based Desktop Computer

Open hardware and open source software platforms bring benefits to both implementers and users in the form of system adaptability and maintainability, and through the avoidance of lock-in, for example. Development of the \riscv\ Instruction Set Architecture and processors during the last ten years has made the implementation of a desktop computer using open hardware, including open processors, and open source software an approaching possibility. We use the SiFive Unmatched development board and Ubuntu Linux, and the recorded experiences of system builders using the Unmatched board to explore the extent to which it is possible to create an open desktop computer. The work identifies current limitations to implementing an open computer system, which lie mainly at the interface between the operating system and hardware components. Potential solutions to the challenges uncovered are proposed, including greater consideration of openness during the early stages of product design. A further contribution is made by an account of the synergies arising from open collaboration in a private-collective innovation process.CC BY 4.0</p

Maintaining interoperability in open source software : A case study of the Apache PDFBox project

Software interoperability is commonly achieved through the implementation of standards for communication protocols or data representation formats. Standards documents are often complex, difficult to interpret, and may contain errors and inconsistencies, which can lead to differing interpretations and implementations that inhibit interoperability. Through a case study of two years of activity in the Apache PDFBox project we examine day-to-day decisions made concerning implementation of the PDF specifications and standards in a community open source software (OSS) project. Thematic analysis is used to identify semantic themes describing the context of observed decisions concerning interoperability. Fundamental decision types are identified including emulation of the behaviour of dominant implementations and the extent to which to implement the PDF standards. Many factors influencing the decisions are related to the sustainability of the project itself, while other influences result from decisions made by external actors, including the developers of dependencies of PDFBox. This article contributes a fine grained perspective of decision-making about software interoperability by contributors to a community OSS project. The study identifies how decisions made support the continuing technical relevance of the software, and factors that motivate and constrain project activity. CC BY 4.0</p

How Can Open Standards Be Effectively Implemented in Open Source?

Part 4: Short Industry PapersInternational audienceMany organisations are currently restricted in their choice of software because of restrictions imposed by existing systems. Challenges include a lack of interoperability and a risk of technological lock-in, which many small companies seek to address by utilising Open Standards and Open Source implementations of such standards when developing and deploying systems. This paper presents an overview of how the industrial research project ORIOS (Open Source software Reference Implementations of Open Standards) seeks to address identified challenges. An overarching goal of the project is to improve understanding within organisations of Open Standards, Open Source Reference Implementations, and the ecosystems around them. This will be done by developing a reference model of necessary and desirable features of an Open Standard, and how Open Standards and their implementations can be utilised by small companies in different usage contexts. An action case study approach will be used as a core strategy for evolving a reference model together with Swedish companies

Towards open government through open source software for web analytics: The case of Matomo

Web analytics technologies provide opportunities for organisations to obtain information about users visiting their websites in order to understand and optimise web usage. Use of such technologies often leads to issues related to data privacy and potential lock-in to specific suppliers and proprietary technologies. Use of open source software (OSS) for web analytics can create conditions for avoiding issues related to data privacy and lock-in, and thereby provides opportunities for a long-term sustainable solution for organisations both in the public and private sectors. The paper characterises use of and engagement with OSS projects for web analytics. Specifically, we contribute a characterisation of use of OSS licensed web analytics technologies in Swedish government authorities, and a characterisation of organisational engagement with the Matomo OSS project for web analytics

Considerations and challenges for the adoption of open source components in software-intensive businesses

Component-Based Software Development is a conventional way of working for software-intensive businesses and OpenSource Software (OSS) components are frequently considered by businesses for adoption and inclusion in softwareproducts. Previous research has found a variety of practices used to support the adoption of OSS components, in-cluding formally specified processes and less formal, developer-led approaches, and that the practices used continue todevelop. Evolutionary pressures identified include the proliferation of available OSS components and increases in thepace of software development as businesses move towards continuous integration and delivery. We investigate workpractices used in six software-intensive businesses in the primary and secondary software sectors to understand currentapproaches to OSS component adoption and the challenges businesses face establishing effective work practices to eval-uate OSS components. We find businesses have established processes for evaluating OSS components and communitiesthat support more complex and nuanced considerations of the cost and risks of component adoption alongside matterssuch as licence compliance and functional requirements. We also found that the increasing pace and volume of softwaredevelopment within some businesses provides pressure to continue to evolve software evaluation processes.CC BY 4.0Corresponding author: [email protected] (Simon Butler)Available online 24 December 2021</p

On Company Contributions to Community Open Source Software Projects

The majority of contributions to community open source software (OSS) projects are made by practitioners acting on behalf of companies and other organisations. Previous research has addressed the motivations of both individuals and companies to engage with OSS projects. However, limited research has been undertaken that examines and explains the practical mechanisms or work practices used by companies and their developers to pursue their commercial and technical objectives when engaging with OSS projects. This research investigates the variety of work practices used in public communication channels by company contributors to engage with and contribute to eight community OSS projects. Through interviews with contributors to the eight projects we draw on their experiences and insights to explore the motivations to use particular methods of contribution. We find that companies utilise work practices for contributing to community projects which are congruent with the circumstances and their capabilities that support their short- and long-term needs. We also find that companies contribute to community OSS projects in ways that may not always be apparent from public sources, such as employing core project developers, making donations, and joining project steering committees in order to advance strategic interests. The factors influencing contributor work practices can be complex and are often dynamic arising from considerations such as company and project structure, as well as technical concerns and commercial strategies. The business context in which software created by the OSS project is deployed is also found to influence contributor work practices. CCBYCC BY 4.0</p