Electromagnetic induction (EMI) systems are used for mapping the soil’s electrical conductivity in near-surface applications. EMI measurements are commonly affected by time-varying external environmental factors, with temperature fluctuations being a big contributing factor. This makes it challenging to obtain stable and reliable data from EMI measurements. To mitigate these temperature drift effects, it is customary to perform a temperature drift calibration of the instrument in a temperature-controlled environment. This involves recording the apparent electrical conductivity (ECa) values at specific temperatures to obtain a look-up table that can subsequently be used for static ECa drift correction. However, static drift correction does not account for the delayed thermal variations of the system components, which affects the accuracy of drift correction. Here, a drift correction approach is presented that accounts for delayed thermal variations of EMI system components using two low-pass filters (LPF). Scenarios with uniform and non-uniform temperature distributions in the measurement device are both considered. The approach is developed using a total of 15 measurements with a custom-made EMI device in a wide range of temperature conditions ranging from 10 °C to 50 °C. The EMI device is equipped with eight temperature sensors spread across the device that simultaneously measure the internal ambient temperature during measurements. To parameterize the proposed correction approach, a global optimization algorithm called Shuffled Complex Evolution (SCE-UA) was used for efficient estimation of the calibration parameters. Using the presented drift model to perform corrections for each individual measurement resulted in a root mean square error (RMSE) of <1 mSm−1 for all 15 measurements. This shows that the drift model can properly describe the drift of the measurement device. Performing a drift correction simultaneously for all datasets resulted in a RMSE <1.2 mSm−1, which is considerably lower than the RMSE values of up to 4.5 mSm−1 obtained when using only a single LPF to perform drift corrections. This shows that the presented drift correction method based on two LPFs is more appropriate and effective for mitigating temperature drift effects.

The acquisition of high-resolution soil information is essential for more environmentally friendly and efficient management of agricultural areas in the context of precision farming. The electrical conductivity (EC) of the soil can be measured quickly and without direct contact using electromagnetic induction (EMI) systems. The EC can be related to soil properties such as soil water content, pore water electrical conductivity, nutrition, clay content and salinity. EMI devices provide an apparent conductivity value that averages electrical conductivity variations with depth. To reconstruct the depth-dependent conductivity from measured data, EMI devices with different coil separations between transmitter and receiver or coil orientations are required. For the measurement with different coil separations, measurements with several commercial devices are commonly combined. However, mutual interference between devices is problematic here, so that measurements with the individual devices must be carried out either one after the other or with sufficient spatial separation, which complicates data acquisition substantially. To simplify EMI data acquisition and to improve depth resolution, an EMI device is required that provides simultaneous measurements with a larger number of freely selectable coil distances. To achieve this, a modular scalable multi-coil system (SELMA) with one transmitter and 12 receiver coils was developed. In the first test configuration, the receiver coils are arranged in a coplanar configuration and equally distributed from 0.3 to 3.6 m in a straight line. The system currently operates at a transmission frequency of 20 kHz and is designed for a measurement range from 2 mS/m to 100 mS/m. The noise of the measured apparent electrical conductivity is below 1 mS/m at a measurement rate of 10 Hz. To achieve modularity, decentralised System-on-Chip modules are used for the data acquisition, which are connected to the control unit (PC) via Ethernet. In addition to the apparent conductivity values, temperatures, pressure, and acceleration are recorded. The reliability of the EMI measurements was checked by repeatedly measuring a transect using a custom-made sled.

Data measured using electromagnetic induction (EMI) systems are known to be susceptible to measurement influences associated with time-varying external ambient factors. Temperature variation is one of the most prominent factors causing drift in EMI data, leading to non-reproducible measurement results. Typical approaches to mitigate drift effects in EMI instruments rely on a temperature drift calibration, where the instrument is heated up to specific temperatures in a controlled environment and the observed drift is determined to derive a static thermal apparent electrical conductivity (ECa) drift correction. In this study, a novel correction method is presented that models the dynamic characteristics of drift using a low-pass filter (LPF) and uses it for correction. The method is developed and tested using a customized EMI device with an intercoil spacing of 1.2 m, optimized for low drift and equipped with ten temperature sensors that simultaneously measure the internal ambient temperature across the device. The device is used to perform outdoor calibration measurements over a period of 16 days for a wide range of temperatures. The measured temperature-dependent ECa drift of the system without corrections is approximately 2.27 mSm−1K−1, with a standard deviation (std) of only 30 μSm−1K−1 for a temperature variation of around 30 K. The use of the novel correction method reduces the overall root mean square error (RMSE) for all datasets from 15.7 mSm−1 to a value of only 0.48 mSm−1. In comparison, a method using a purely static characterization of drift could only reduce the error to an RMSE of 1.97 mSm−1. The results show that modeling the dynamic thermal characteristics of the drift helps to improve the accuracy by a factor of four compared to a purely static characterization. It is concluded that the modeling of the dynamic thermal characteristics of EMI systems is relevant for improved drift correction.

Abstract. CubeSats have become very popular science platforms in the past decades, leading to a continuously increasing number of developers in the academic field. For science missions, customized payload electronics have to be developed, depending on measurement tasks and requirements. Especially for the deployment of complex remote sensing payloads, state-of-the-art performance is needed to provide operational control and specific data processing, e.g., for image sensors. Highly integrated system-on-module (SoM) architectures offer low resource requirements regarding power and mass, but moderate to high processing power capabilities. However, a requirement to use a standard SoM in a satellite is to quantify its radiation tolerance. The radiation environment has been modeled, estimating the hazards at module level and reducing the risks to an acceptable level by applying appropriate mitigation techniques. This approach results in a sensor electronics design that combines hardware and software redundancies to assure system availability and reliability for long-life science missions in low earth orbits. Integrated in a miniaturized limb sounding instrument for atmospheric remote sensing imaging, the payload electronics will be deployed on a technology demonstration satellite for in-orbit verification.

Chemical ionization mass spectrometry (CIMS) provides high sensitivity for ultra-sensitive trace gas measurements in the atmosphere. The presented ion source is used to replace radioactive Po ion sources. First in-field test runs have been done using an airborne instrument flown on the StratoClim campaign in Greece, Kalamata 2016. Espe-cially stratospheric measurements at ambient pressures lower than 100 hPa require improved sensitivity. Therefore, a chemical ionization (CI) time-of-flight (TOF) instrument using a dielectric barrier discharge (DBD) ion source and a high-transmission transfer stage has been set-up and characterized. A new concept including the ion molecule reaction (IMR) zone inside an ion funnel is used.

The energy consumption of information and communication technology (ICT) is still increasing. Even though several solutions regarding the hardware side of Green IT exist, the software contribution to Green IT is not well investigated. The carbon footprint is one way to rate the environmental impacts of ICT. In order to get an impression of the induced CO2 emissions of software, we will present a calculation method for the carbon footprint of a software product over its life cycle. We also offer an approach on how to integrate some aspects of carbon footprint calculation into software development processes and discuss impacts and tools regarding this calculation method. We thus show the relevance of energy measurements and the attention to impacts on the carbon footprint by software within Green Software Engineering.

The awareness for software as an important player regarding the energy consumption caused by ICT steadily increased in the past years. The impact of software on the energy consumption is also more and more accepted by the research community under the umbrella of sustainability in general. Nevertheless, the end user is still only slightly or not addressed in the research activities regarding the whole energy consumption of software over its complete lifecycle. Also other stakeholders, e.g. administrators, designers, developers etc., are not in the focus of creating awareness for the aforementioned topics. In this contribution, we therefore focus on ideas, approaches, and challenges in developing a general-purpose labelling process for green and sustainable software products and websites. At first we provide a literature roundup, followed by the elaboration of requirements for the creation of a sustainability label for software products in general based on already existing and new approaches. On a first attempt, we furthermore concentrate on a labelling process for sustainable as well as green websites and sum up with a discussion followed by an outlook on our future work.

Sustainability intersects Information and Communication Technology in two domains: Green IT (how can we make ICT itself more sustainable?) and Green by IT (how can we achieve sustainability through ICT?). On a closer look, it is software that links these two fields: In "classic" Green IT, there are many ways to build and use hardware in a more energy-efficient way. On the software side, Green by IT has often been software-based until now, involving tools that help to optimize logistics and automate processes to save energy, for example. However, the debate over software-induced energy consumption is just beginning. To date, few studies have been conducted about the energy saving potential of software itself. Therefore, it is important to investigate the meaning of sustainable software and sustainable software engineering. This chapter provides definitions of these concepts. In addition, it presents a reference model of sustainable software as well as its engineering. However, it provides only a short introduction of the model itself. The sub-model "Sustainability Criteria for Software Products" and sustainable software process models are examined in greater detail.

We summarize recent theoretical results as well as numerical results on the feedback stabilization of first order quasilinear hyperbolic systems (on networks). For the stabilization linear feedback controls are applied at the nodes of the network. This yields the existence and uniqueness of a C 1-solution of the hyperbolic system with small C 1-norm. For this solution an appropriate L 2-Lyapunov function decays exponentially in time. This implies the exponential stability of the system. A numerical discretization of the Lyapunov function is presented and a numerical analysis shows the expected exponential decay for a class of first-order discretization schemes. As an application for the theoretical results the stabilization of the gas flow in fan-shaped pipe networks with compressors is considered.

The energy consumption of information and communica tion technology (ICT) is still increasing. Several solutions regarding the hardware side of Gre en IT exist, until now the software contribu tion to Green IT is not considered sufficiently apart from scientific research . In our paper , we discuss a new method of improving the energy efficiency of software during its develo pment, by putting energy efficiency m easurements into practice . Therefore, we measure and rate energy consumption and efficiency during the software development process , based upon software testing and Continuous Integration (CI).

The two big fields of sustainability and Information and Communication Technology (ICT) are Green IT (how can we make ICT itself more sustainable) and Green by IT (how can we encourage sustainability by ICT). Taking a deeper look, software links these two areas: Regarding Green IT, there are a lot of solutions to build and use hardware in a more energy efficient way. But the debate how energy-intensive software might be is just beginning. In contrast, Green by IT is often software-based, e.g. by tools that help to optimize logistics and automate processes to save energy. But until now there are no considerations about the energy saving potential of software itself. Therefore, it is useful to take a closer look at what green software and green software engineering are. In our paper, we will describe a reference model for green and sustainable software, as well as its engineering and also give some definitions. Though, we will just give a short introduction of the model itself and, to distinguish our work from our previous research, zoom in on the sub model “Sustainability Criteria for Software Products”. Additionally, we describe a model to measure the energy efficiency of software and give an example of measuring results in our contribution. The next step is to clearly differentiate from other measurement models to position our approach within other efforts of software’s energy consumption.

We consider the subcritical gas flow through star-shaped pipe networks. The gas flow is modeled by the isothermal Euler equations with friction. We stabilize the isothermal Euler equations locally around a given stationary state on a finite time interval. For the stabilization we apply boundary feedback controls with time-varying delays. The delays are given by C 1-functions with bounded derivatives. In order to analyze the system evolution, we introduce an L 2-Lyapunov function with delay terms. The boundary controls guarantee the exponential decay of the Lyapunov function with time.

The energy consumption of information and communication technology (ICT) is still increasing. Since several concepts regarding hardware solutions for Green IT exist, the contribution of software to Green IT is still not well investigated. This comprises the production and the usage impact of software on energy consumption. In our paper, we discuss this contribution. Especially, we present a model that integrates Green IT aspects into software engineering processes with agile methods in order to produce "greener" software from scratch.

The energy consumption of information and communication technology (ICT) is still increasing. Even though, up to now, several solutions regarding the hardware side of Green IT exist, the software contribution to Green IT is not well investigated. In our paper, we discuss how to integrate some aspects of carbon footprint calculation into software development processes and we show how ongoing energy efficiency measurements can be established as an integral part of a software development project.

We consider the feedback stabilization of quasilinear hyperbolic systems on star-shaped networks. We present boundary feedback controls with varying delays. The delays are given by C1-functions with bounded derivatives. We obtain the existence of unique C1-solutions on a given finite time interval. In order to measure the system evolution, we introduce an L2-Lyapunov function with delay terms. The feedback controls yield the exponential decay of the Lyapunov function with time. This implies the exponential stability of the system. Our results can be applied on the stabilization of the isothermal Euler equations with friction that model the gas flow in pipe networks.

We consider the isothermal Euler equations without friction that simulate gas flow through a pipe. We consider the problem of boundary stabilisation of this system locally around a given stationary state. We present a feedback law that is linear in the physical variables and yields exponential decay of the system state. For the numerical solution of hyperbolic systems of conservation laws, the Jin-Xin relaxation scheme can be used. Therefore, we also consider the boundary stabilisation of the relaxation system by the linear Riemann feedback and present numerical examples that show the rapid exponential decay of the stabilised system.