20 research outputs found
Piecewise linearity in the approximation for accurate quasiparticle energy predictions
We identify the deviation from the straight line error (DSLE) -- i.e., the
spurious non-linearity of the total energy as a function of fractional particle
number -- as the main source for the discrepancy between experimental vertical
ionization energies and theoretical quasiparticle energies, as obtained from
the and +SOSEX approximations to many-body perturbation theory (MBPT).
For self-consistent calculations, we show that suffers from a small DSLE.
Conversely, for perturbative and +SOSEX calculations the DSLE
depends on the starting point. We exploit this starting-point dependence to
reduce (or completely eliminate) the DSLE. We find that the agreement with
experiment increases as the DSLE reduces. DSLE-minimized schemes, thus, emerge
as promising avenues for future developments in MBPT
Predicting photoemission : From the single-particle interpretation to the many-electron picture
Planning Area Coverage with Low Priority
There exist multiple papers about how to plan satellite image acquisitions in order to cover an area of interest which is larger than one image swath. All of these consider the case that the to-be-covered area is of greatest interest and that the resulting plan may be executed without disturbance. Within the EnMAP mission however, images of higher priority are requested such that they are acquired using one pass only. Requests to cover a whole area are reserved for the background mission, which has lowest priority and is introduced to fulfill secondary mission goals on a longer time horizon. Planning for the background mission must therefore take into account that any time before sending the commands to the spacecraft, new requests may be received, whose acquisitions block planned acquisitions of the area coverage. In this paper we describe the different options the EnMAP Mission Planning team considers to handle this scenario
A Modern Approach to Visualise Structured and Unstructured Space Missions' Data
In this paper the Visualisation and Data Analysis (ViDA) project, currently being developed at the German Space Operations Center (GSOC), is presented. ViDA is a modern, interactive, web-based frontend tool designed to efficiently explore various types of data generated by space missions. It is more than just a telemetry display tool and, as such, includes features from business intelligence, data science and AI tools, while being focused on the multi-spacecraft operations use case. The paper describes how the big data challenges (volume, variety, variability, complexity, value) in the context of spacecraft operations have been addressed and how the adopted solutions have been integrated into ViDA. It also highlights the importance of contextual knowledge as crucial point for the design and implementation of ViDA. The techniques used for creating appropriate visual representations of the data and their relations are described. Such visualisations are specifically designed to deliver interpretable results to the users, thus helping them to quickly extract knowledge from them during their analytical process. Finally, the integration of ViDA into the ground system and its connections to the other tools in the telemetry/telecommand chain are discussed
Towards Generic Planning of Optical Links
The paper at hand presents our concept for upcoming space-ground optical Mission Planning systems at DLR GSOC. In cooperation with TESAT we have more than 15 years of operational experience for optical links. We have thoroughly discussed challenges and needs of optical mission planning systems to enable potential customers for deployment of full end-to-end systems. While earlier systems such as TDP-1 (Technical Demonstration Project) or EDRS (European Data Relay System) had individual requirements and interfaces, the new system is capable to consider ad-hoc additional requirements and generic interfaces. This flexibility is a big step towards our goal of a fully interoperable control center infrastructure. We show in the paper at hand how the new concept will be implemented and validated. The developed architecture is based upon the "Program for INteractive Timeline Analysis" (PINTA). PINTA enables the User in this specific use case to manually schedule links from a set of precalculated visibilities and trigger an automated link export for both optical terminals (on ground and in orbit) for their execution. At first, PINTA will be used offline for scheduling the links of the new DLR optical ground station Almería; in the frame of the Global Optical Ground Station Network (GlobeON). The subsequent development step will result in embedding these functionalities in another architecture which builds upon the new generic interfaces, replacing PINTA with the GSOC's generic Reactive Planning framework and its frontend PintaOnWeb for visual support, modification and analysis. This tool suite will allow for automatically triggered incremental planning runs immediately upon reception of new input (e.g. orbit updates, spacecraft and ground station unavailability) instead of manually initiated runs or semi-automated planning at fixed intervals. Finally, more elaborated interactions with the spacecraft and ground station operations and the prediction as well as real-time information about local weather conditions are aimed to be included into the automated planning process
The GSOC satellite telemetry analysis framework
Given the huge amount of data a modern spacecraft sends back to Earth, monitoring its status without the aid of automatization has become an almost unfeasible task.
To assist engineers, the Automated Telemetry Health Monitoring System (ATHMoS) is being developed at the German Space Operation Center. It employs a semi-supervised machine learning approach to automatically detect novel behavior or outliers in satellite telemetry. The algorithms and models of ATHMoS are further designed to detect slowly varying trends in telemetry to rise awareness of potential problems of a satellite at an early stage. Since expert knowledge of engineers is indispensable for the correct assessment of certain behaviour of telemetry data and for contextualizing it, the automatically trained ATHMoS models can be augmented by engineers.
To ease the interpretation of ATHMoS results and to give engineers a powerful and comprehensive platform for their investigations, ATHMoS is embedded in the new Visualization and Data Analysis (ViDA) framework. ViDA further allows engineers to access and plot all telemetry data sent to ground and to run customized analyses
Neukonzeption der Typisierung im SGB-II-Bereich : Vorgehensweise und Ergebnisse
"Seit 2006 erstellt das IAB Vergleichstypen im Rechtskreis des Sozialgesetzbuches (SGB) II. Anlass der Typisierung sind starke Unterschiede in der wirtschaftlichen und sozialen Struktur von Regionen. Diese Unterschiede wirken sich als regionale Rahmenbedingungen unmittelbar auf die Arbeit der Jobcenter, den Trägern der Grundsicherung, aus. Wenn Verbesserungspotenziale aufgedeckt oder die Kennzahlen von unterschiedlichen Jobcentern verglichen werden sollen, dann ist es notwendig, diese regionalen Disparitäten zu berücksichtigen. Dies geschieht, indem Jobcenter mit ähnlichen regionalen Rahmenbedingungen für ihre Zielerreichung einem Vergleichstypen zusammengefasst werden. Die Typisierung ist damit ein wichtiges Werkzeug für die arbeitsmarkt- und die sozialpolitische Steuerung. Sie wird in unregelmäßigen Abständen aktualisiert, um zu berücksichtigen, dass sich Rahmenbedingungen mittelfristig ändern. Die vorliegende Neukonzeption geht jedoch deutlich über eine einfache Aktualisierung hinaus. Sie verfolgt im Wesentlichen zwei Ziele: Erstmals sollen drei Zieldimensionen des SGB II explizit und gleichgewichtig in die Auswahl der relevanten Rahmenbedingungen einfließen. Zudem sollen die für das SGB II spezifischen Problemlagen ebenfalls stärker explizit berücksichtigt werden. Dazu wurden statistische Indikatoren neu berechnet, die bisher nicht zur Verfügung standen. Der vorliegende Bericht dokumentiert die Neukonzeption der Typisierung im Detail und stellt deren Ergebnisse vor.
Benchmark of GW Approaches for the GW100 Test Set
For the recent GW100 test set of molecular ionization energies, we present a comprehensive assessment of different GW methodologies: fully self-consistent GW (scGW), quasiparticle self-consistent GW (qsGW), partially self-consistent GW0 (scGW0), perturbative GW (G0W0), and optimized G0W0 based on the minimization of the deviation from the straight-line error (DSLE-min GW). We compare our GW calculations to coupled-cluster singles, doubles, and perturbative triples [CCSD(T)] reference data for GW100. We find scGW and qsGW ionization energies in excellent agreement with CCSD(T), with discrepancies typically smaller than 0.3 eV (scGW) and 0.2 eV (qsGW), respectively. For scGW0 and G0W0 the deviation from CCSD(T) is strongly dependent on the starting point. We further relate the discrepancy between the GW ionization energies and CCSD(T) to the deviation from straight line error (DSLE). In DSLE-minimized GW calculations, the DSLE is significantly reduced, yielding a systematic improvement in the description of the ionization energies
The Compasso Mission: Operational Strategies for Validating Optical Technologies On-Board the ISS
Compasso is an in-orbit validation mission to demonstrate new optical technologies for future GNSS constellations. It is hosted on the Airbus Bartolomeo platform on the International Space Station with a launch scheduled for December 2025. The paper illustrates the main design choices with regards to Compasso operations and the ground segment that where made in the current preliminary design phase of the mission.
One of the primary mission goals of Compasso, which drives the operations design the most, is the demonstration of bi-directional time transfer via optical links from space to ground. The paper illustrates the general challenges for the optical links, specifically the ones that come with human spaceflight. Under any circumstances it is strictly prohibited that the crew safety is jeopardised by radiation emitting activities, which is why the current link planning strategy and architecture is designed to ensure that no laser activity is planned and executed during any safety critical activities on board the ISS via a fourfold redundant inhibit concept. Since Compasso is dependent on the Bartolomeo, Columbus and ISS infrastructure in general, the paper also shows how Compasso will be integrated in all these programs. An example for this is the TM/TC data routing via the ISS assets. Besides that, the operations concept shows how a payload on the ISS can be operated safely and how the in-orbit validation will be coordinated and conducted