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This paper describes a low-cost extension for an imaging observation instrument as a radiation monitor. Adapted image processing methods enable discrimination between measured data and sensor / radiation-specific hazards and drives mitigation techniques to improve mission lifetime.

Commercial off-the-shelf (COTS) CMOS sensors are increasingly used in scientific applications on nanosatellites. Applying a software-based approach and in addition to their image acquisitions tasks, these CMOS sensors can be used to detect ionizing particles to improve the fault tolerance of imaging instruments on nanosatellites without the need for additional hardware. A challenge in using COTS components for this approach is that essential radiation test data and important parameters such as the thickness of the sensitive epitaxial layer are typically not available. With a simplified calibration approach, we determine the epitaxial layer thickness and calibrate the deposited energy sensitivity with minimal measurement time and steps and minor requirements on the test facility. A forward model for particle track length determination with an increased angle scattering of incident protons is used to handle stronger parameter uncertainties of the test setup. It is shown that the currently used CMOS sensor (HWK1910A) is a suitable candidate for a radiation monitor, based on the determined epitaxial layer thickness and the deposited energy calibration factor, in combination with the in-orbit mission data. This enables capabilities for more individual protection measures in case of unexpected radiation environments.

Large commercial of the shelf pixel arrays in current remote sensing instruments used in CubeSats make on-board processing increasingly important and enables data improvement. Therefore, we first consider the individual steps of the adapted bad pixel detection algorithm - ISMFD. In particular, we consider pixel-to-pixel variations and temporal flickering of pixels in commercial of the shelf sCMOS imaging sensors. We were able to detect an increase of bad pixels from (2.05±0.01)% to (4.1±0.1)% using real measurement images of the flying remote sensing instrument AtmoSHINE. A preliminary implemented adaptive on-board binning method was able to achieve a constant signal-to-noise-ratio on an image with a dynamic light intensity. The additional consideration of bad pixels in the binning method could demonstrate the achievement of data quality of the future remote sensing instrument AtmoLITE.

Spatial heterodyne interferometers are an enabling technology to build highly miniaturized optical instruments for the observation of faint emissions in the atmosphere. They are particularly suited for the deployment on nano- or micro-satellite constellations. One application of the SHI technology is a middle atmosphere temperature sounder based on the measurement of relative intensities emitted by the O2 atmospheric band system. Beside basic design considerations, aspects of the opto-mechanical design and assembly of a monolithic SHI for a space application are addressed. For the characterization of such an instrument, a light stimulus based on a Köhler illuminator is presented.

Observations from aircraft and balloons with remote sensing instruments are an important method to investigate processes within the Earth environment. These applications require powerful computing systems that must be developed or adapted for the measurement task and requirements. In particular, imaging spectrometers generate high data rates by almost 10,000 pixels at about 4,000 frames per second. Accordingly, high performance is needed to provide operational control and data processing with high data bandwidth and the capability to store this data also during long duration flights.A modular processing system architecture based on modified industrial grade board components has been developed to meet these high requirements for processing power and storage capacity. The major advantages of this approach are flexibility, (re)programmability, modularity and module re-use in order to attain lower development time and costs. However, it is a challenge to design this processing system to be suitable for the harsh environments of aircraft or balloon applications in terms of temperature range, humidity and vibration.With an efficient approach ruggedized characteristics are achieved using a conduction cooled design in combination with components based on VPX standard and customized backplane transition modules in order to reduce operational risk with necessary measures of mitigation techniques. This approach results in a processing system that combines hardware and software redundancies to assure system availability and reliability for long duration flights.In this presentation the compact flight proven system design is presented that has been used in recent years for high spectral resolution limb-observations by the GLORIA (Gimballed Limb Observer for Radiance Imaging of the Atmosphere) spectrometer aboard the HALO and Geophysica high-altitude aircrafts. Various system configurations and performance results will be shown, which have been achieved in the current design and will be applied in future balloon campaigns.

This article presents the characterization and analysis of a commercial off-the-shelf (COTS) CMOS detector utilized in a miniaturized satellite payload for atmospheric temperature measurements. To evaluate the performance of the selected CMOS detector, a series of tests were performed. The temperature dependent dark current, the readout noise and the system gain are determined, which are provided for the subsequent system performance evaluation and data processing. A case study is established to simulate the space radiation effect to determine the needed shielding thickness on the instrument. The effect of radiation damage on the CMOS image sensors is investigated using a Co-60 Gamma radiation source.

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.

In this paper we report the results of the assessment of changes in the dark signal delivered by three silicon photomultiplier (SiPM) detector arrays, fabricated by three different manufacturers, when irradiated with cold neutrons (wavelength λ n =5 A or neutron energy of E n =3.27 meV) up to a neutron dose of 6×10 12 n/cm 2 . The dark signals as well as the breakdown voltages ( V br ) of the SiPM detectors were monitored during the irradiation. The system was characterized at room temperature. The analog SiPM detectors, with and without a 1 mm thick Cerium doped 6 Li-glass scintillator material located in front of them, were operated using a bias voltage recommended by the respective manufacturer for a proper detector performance. I out -V bias measurements, used to determine the breakdown voltage of the devices, were repeated every 30 s during the first hour and every 300 s during the rest of the irradiation time. The digital SiPM detectors were held at the advised bias voltage between the respective breakdown voltage and dark count mappings repeated every 4 min. The measurements were performed on the KWS-1 instrument of the Heinz Maier-Leibnitz Zentrum (MLZ) in Garching, Germany. The two analog and one digital SiPM detector modules under investigation were respectively fabricated by SensL (Ireland), Hamamatsu Photonics (Japan), and Philips Digital Photon Counting (Germany).

A CubeSat-sized limb sounder utilizing a Spatial Heterodyne Spectrometer for the detection of the O2 Atmospheric A-Band is presented. The purpose of the instrument is to measure vertical profiles of temperature in the middle atmosphere.

A highly miniaturized limb sounder for the observation of the O2 A-Band to derive temperatures in the mesosphere and lower thermosphere is presented. The instrument consists of a monolithic spatial heterodyne spectrometer (SHS), which is able to resolve the rotational structure of the R-branch of that band. The relative intensities of the emission lines follow a Boltzmann distribution and the ratio of the lines can be used to derive the kinetic temperature. The SHS operates at a Littrow wavelength of 761.8 nm and heterodynes a wavelength regime between 761.9 nm and 765.3 nm with a resolving power of about 8000 considering apodization effects. The size of the SHS is 38 × 38 × 27 mm3 and its acceptance angle is ±5°. It has an etendue of 0.014 cm2 sr. Complemented by a front optics with a solid angle of 0.65° and a detector optics, the entire optical system fits into a volume of about 1.5 liters. This allows to fly this instrument on a 3 or 6 unit CubeSat. The vertical field of view of the instrument is about 60 km at the Earth's limb if operated in a typical low Earth orbit. Integration times to obtain an entire altitude profile of nighttime temperatures are in the order of one minute for a vertical resolution of 1.5 km and a random noise level of 1.5 K. Daytime integration times are one order of magnitude shorter. This work presents the design parameters of the optics and a radiometric assessment of the instrument. Furthermore it gives an overview of the required characterization and calibration steps. This includes the characterization of image distortions in the different parts of the optics, flat fielding and the spectral power estimation.

The Institute for Atmospheric and Environmental Research at the University of Wuppertal and the Institute of Energy and Climate Research Stratosphere at Research Center Juelich developed a CubeSat payload for atmospheric research. The payload consists of a small interferometer for the observation of airglow near 762 nm. The line intensities of the oxygen A-band are used to derive temperatures in the mesosphere and lower thermosphere region. The temperature data will be used to analyze dynamical wave structures in the atmosphere. The interferometer technology chosen to measure the ro-vibrational structure of the O2 atmospheric band near 762 nm is a spatial heterodyne interferometer originally proposed by Connes in 1958. It can be designed to deliver extraordinary spectral resolution to resolve individual emission lines. The utilization of a two-dimensional imaging detector allows for recording interferograms at adjacent locations simultaneously. Integrated in a six-unit CubeSat, the instrument is designed for limb sounding of the atmosphere. The agility of a CubeSat will be used to sweep the line-of-sight through specific regions of interest to derive a three-dimensional image of an atmospheric volume using tomographic reconstruction techniques.

Results are presented of the opto-electrical characterization of two analog and one digital SiPM arrays, produced by three different manufacturers (SensL, Hamamatsu, and Philips), before and after irradiation with cold neutrons (with a wavelength of 5 A) at the KWS-1 instrument of the Heinz Maier-Leibnitz Zentrum (MLZ) in Garching, Germany. Irradiation doses of up to 6×1012 n/cm2 were used. We assessed the neutron irradiation induced changes in the temperature dependent dark signal and breakdown behaviors, as well as changes in the photodetection efficiency of the Philips Digital Photon Counting (PDPC) array. We conclude that all three technologies could be used in Small-Angle Neutron Scattering (SANS) experiments.

To establish improved therapies for patients suffering from severe neurological and psychiatric diseases, a demand controlled and desynchronizing brain-pacemaker has been developed with techniques from statistical physics and nonlinear dynamics. To optimize the novel therapeutic approach, brain activity is investigated with a Magnetoencephalography (MEG) system prior to surgery. For this, a real time data acquisition system for a 148 channel MEG and online signal processing for artifact rejection, filtering, cross trial phase resetting analysis and three-dimensional (3-D) reconstruction of the cerebral current sources was developed. The developed PCI bus hardware is based on a FPGA and DSP design, using the benefits from both architectures. The reconstruction and visualization of the 3-D volume data is done by the PC which hosts the real time DAQ and pre-processing board. The framework of the MEG-online system is introduced and the architecture of the real time DAQ board and online reconstruction is described. In addition we show first results with the MEG-Online system for the investigation of dynamic brain activities in relation to external visual stimulation, based on test data sets.

Various centres of the German Helmholtz Association (HGF) started in 2012 to develop a modular data acquisition (DAQ) platform, covering the entire range from detector readout to data transfer into parallel computing environments. This platform integrates generic hardware components like the multi-purpose HGF-Advanced Mezzanine Card or a smart scientific camera framework, adding user value with Linux drivers and board support packages. Technically the scope comprises the DAQ-chain from FPGA-modules to computing servers, notably frontend-electronics-interfaces, microcontrollers and GPUs with their software plus high-performance data transmission links. The core idea is a generic and component-based approach, enabling the implementation of specific experiment requirements with low effort. This so called DTS-platform will support standards like MTCA.4 in hard- and software to ensure compatibility with commercial components. Its capability to deploy on other crate standards or FPGA-boards with PCI express or Ethernet interfaces remains an essential feature. Competences of the participating centres are coordinated in order to provide a solid technological basis for both research topics in the Helmholtz Programme ``Matter and Technology'': ``Detector Technology and Systems'' and ``Accelerator Research and Development''. The DTS-platform aims at reducing costs and development time and will ensure access to latest technologies for the collaboration. Due to its flexible approach, it has the potential to be applied in other scientific programs.

The Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) is an imaging limb emission sounder operating in the thermal infrared region. It is designed to provide measurements of the upper troposphere/lower stratosphere with high spatial and high spectral resolution. The instrument consists of an imaging Fourier transform spectrometer integrated into a gimbal. The assembly can be mounted in the belly pod of the German High Altitude and Long Range research aircraft (HALO) and in instrument bays of the Russian M55 Geophysica. Measurements are made in two distinct modes: the chemistry mode emphasises chemical analysis with high spectral resolution, and the dynamics mode focuses on dynamical processes of the atmosphere with very high spatial resolution. In addition, the instrument allows tomographic analyses of air volumes. The first measurement campaigns have shown compliance with key performance and operational requirements.

A new two-dimensional position-sensitive detector system for small-angle neutron scattering experiments is under development. It is based on a 60/spl times/60 cm/sup 2/ large /sup 6/Li-glass scintillator for the neutron capture and dispersion of the emitted light on an array of photomultiplier tubes for the derivation of the event position. For subthermal neutrons of 8 /spl Aring/, an efficiency of 96% and a spatial resolution of 8 mm are to be achieved. Major improvements have been made in the signal- and data-processing branch, which aims at an electronic dead time of 1 /spl mu/s. A fast digitalization method using free-running analog-to-digital converters for each photomultiplier combined with field-programmable gate arrays for a parallel event detection in all channels has been applied. A subsequent farm of up to 16 floating-point digital signal processors is used to provide enough computing power for an improved reconstruction of the event position according to a maximum likelihood method.

For the ultraslow extraction system of the COler SYnchrotron COSY a direct digital synthesis system is being developed. LabVIEW from National Instruments has been chosen as a tool for the simulation of the digital signal processing algorithms as well as the generation of test sequences. In order to generate adjustable band-limited noise centered at a carrier frequency, alternative algorithms have been studied. LabVIEW permits the interactive variation of relevant system parameters by means of a graphical language in order to study the quality of the frequency band limitation as a function of noise parameters, digital accuracy and frequency range and to generate test sequences by means of a real-time function generator. Advantages and limitations of LabVIEW for such applications are discussed.

For two-dimensional scintillation detectors based on position-sensitive photomultipliers, a new PCI or cPCI unit has been developed. It aims at fast signal and data processing by the usage of advanced technologies like digital signal processors and field-programmable gate arrays. The main features of this design are described in this paper. Digital test measurements were carried out showing that the chosen design complies with the requirements of nuclear pulse processing for such applications.

An open metal cavity loaded with a ceramic dielectric resonator and a lumped inductor - capacitor structure allows for simultaneous excitation of the TE 01δ dielectric resonator mode at 2 GHz and a lumped element mode at 100 MHz. The measured quality factors are about 7,000 and 400, respectively. Both modes exhibit strongly overlapping evanescent fields above the aperture outside the cavity. These fields can be used for dielectric and conductivity measurements on liquids stored in non-metallic bottles. The simultaneous use of both modes enables liquid category identification within one second. This method has been successfully applied for bottle scanning in checkpoints.

A high performance read-out system for imaging FTS instruments based on equal time sampling designs with data post processing is presented. It can perform a data storage throughput up to 160 MByte/s.

The performance of scintillation detectors with the advanced scintillator material /sup 6/Li /sup 158/Gd (/sup 11/BO/sub 3/)/sub 3/ was compared with conventional /sup 3/He proportional counters at the IPNS spallation source at the Argonne National Laboratory. The complex neutron and gamma flux was measured with both detector types simultaneously in time-of-flight (TOF) mode. Initial experiments demonstrated that both detectors have a sensitivity of about 60% for thermal neutrons. In addition, both detectors exhibited the same low gamma sensitivity. Furthermore the temporal resolution for neutrons and gammas were also shown to be of the same order.

During the upgrade of the small-angle neutron scattering instrument KWS-1 at the research reactor FRJ-2, the 15-yr-old detector system has been replaced. While the Anger camera-based concept of the detector remained unchanged, the signal and data processing branch has been completely revised. Because of higher count rate requirements, a highly configurable parallel readout electronics has been developed aiming at counting rates of several hundred kilohertz. The whole detector system has been recently installed at KWS-1 and measurements to study the system performance have been carried out. The linearity and spatial resolution of the new detector have been determined by an analysis of an acquired image taken with a hole diaphragm in front of the scintillator. The overall system dead time has been measured by comparing the detector count rates at several scattering intensities to the count rates achieved with a fission chamber. Finally, scattering patterns of well-known samples have been taken in order to demonstrate the quality of the acquired images.

State of the art HTS SQUID sensors have already attained a sensitivity which makes them interesting for biomagnetical and especially cardiological applications. Many high quality measurements of magnetic signals emanating from the human heart have been performed with HTS sensors. With the improvement in sensitivity, the cancellation of environmental noise became one of the major problems for measuring high quality MCGs. Therefore, most of these measurements have been performed in expensive magnetically shielded rooms (MSRs) with high shielding factors (e.g. PTB, Berlin, Germany or SSL, Japan). A different, less expensive approach is the use of gradiometric arrangements of the sensors to cancel environmental disturbances. As a compromise, moderate shielding may be combined with gradiometry to keep the effort on both alternatives to a minimum.

In Non-Destructive Evaluation (NDE), eddy current techniques are commonly used for the detection of hidden material defects in metallic structures. Conventionally, one works with an excitation coil generating a field at a distinct frequency. The eddy currents are deviated by materials flaws and the resulting distorted field is sensed by a secondary coil. Because of the law of induction, this technique has its limitations in the low frequency range. This leads to a decrease of the Probability of flaw Detection (POD) in larger depths.

Superconducting Quantum Interference Devices (SQUIDs) are extremely sensitive detectors for the measurement of magnetic flux. Especially the current High Temperature Superconductor (HTS) SQUIDs, which can be operated at liquid nitrogen temperature with easy cryogenic requirement, are well suited for the practical use [1]. Nowadays this HTS-SQUIDs are used for applications like the detection and localization of currents within the human heart, for nondestructructive evaluation of materials and for geological exploration.

The water status in plant leaves is a good indicator for the water status in the whole plant revealing stress if the water supply is reduced. The analysis of dynamic aspects of water availability in plant tissues provides useful information for the understanding of the mechanistic basis of drought stress tolerance, which may lead to improved plant breeding and management practices. The determination of the water content in plant tissues during plant development has been a challenge and is currently feasible based on destructive analysis only. We present here the application of a non-invasive quantitative method to determine the volumetric water content of leaves and the ionic conductivity of the leaf juice from non-invasive microwave measurements at two different frequencies by one sensor device. A semi-open microwave cavity loaded with a ceramic dielectric resonator and a metallic lumped-element capacitor- and inductor structure was employed for non-invasive microwave measurements at 150 MHz and 2.4 Gigahertz on potato, maize, canola and wheat leaves. Three leaves detached from each plant were chosen, representing three developmental stages being representative for tissue of various age. Clear correlations between the leaf- induced resonance frequency shifts and changes of the inverse resonator quality factor at 2.4 GHz to the gravimetrically determined drying status of the leaves were found. Moreover, the ionic conductivity of Maize leaves, as determined from the ratio of the inverse quality factor and frequency shift at 150 MHz by use of cavity perturbation theory, was found to be in good agreement with direct measurements on plant juice. In conjunction with a compact battery- powered circuit board- microwave electronic module and a user-friendly software interface, this method enables rapid in-vivo water amount assessment of plants by a handheld device for potential use in the field.