Development of an extreme ultraviolet imaging spectrometer for the BepiColombo mission

Extreme and far ultraviolet imaging spectrometers are proposed for the low-altitude orbiter of the BepiColombo mission. The UV instrument, consisting of the two spectrometers with common electronics, aims at measuring (1) emission lines from molecules, atoms and ions present in the Mercury’s tenuous atmosphere and (2) the reflectance spectrum of Mercury’s surface. The instrument pursues a complete coverage in UV spectroscopy. The extreme UV spectrometer covers the spectral range of 30–150 nm with the field of view of 5.0°, and the spectrum from 130 to 430 nm is obtained by the far UV spectrometer. The extreme UV spectrometer employs multi-layer coating technology to enhance its sensitivity at particular emission lines. This technology enables us to identify small ionospheric signatures such as He II (30.4 nm) and Na II (37.2 nm), which could not be detected with conventional optics.     

基于虚拟仪器技术的直升机机载电子设备故障检测系统设计

本文以陆航某部ATE的设计过程为基础,介绍了直升机机载电子设备故障检测系统的硬件组成,并详细阐述了系统软件平台的层次结构和设计方法。     

网络虚拟实验体系结构及其实现

根据网络虚拟实验的重要性及其在现阶段存在的不足，指出了研发网络虚拟实验体系结构的重大意义，提出了一种可能的实现方式并对其构成模块的结构和关键技术作了详尽的阐述。     

Petri网模型在智能型电话管理系统开发中的应用

基于Petri网模型的智能仪器监控软件设计方法是一种新型的软件设计方法。运用该方法 ,在对智能型电话管理系统中的内部因素和外部因素综合分析的基础上 ,结合Petri网模型理论 (Petri -net-modeltheo ry) ,找到了智能仪器监控软件的形式化描述技术和数学化设计方法 ,给出了其工程化的解决方案。工程应用实践表明 ,Petri网模型及其在智能仪器监控软件设计中的应用是可行而成功的。     

Ultraviolet 3D digital image correlation applied for deformation measurement in thermal testing with infrared quartz lamps

In thermal-structural testing of hypersonic materials and structures, deformation measurement on the front surface of an object directly heated by quartz lamps is highly necessary and very challenging. This work describes a novel front-surface high-temperature deformation measurement technique, which adopts ultraviolet 3D digital image correlation (UV 3D-DIC) to observe and measure the high-temperature deformation fields on front surfaces directly heated by quartz lamps. Compared with existing blue light DIC techniques, the established UV 3D-DIC, which combines UV CCD camera, active UV illumination and bandpass filter imaging, can effectively suppress the strong disturbing light emitted by the quartz lamps and the heated sample itself during heating process. Two experiments were carried out to verify the robustness and accuracy of the developed technique: (1) direct observation of front surfaces of a hypersonic thermal structure sample heated from room temperature to 1050 °C, and (2) front-surface thermal stain and coefficient of thermal expansion (CTE) measurement of an Inconel 718 sample up to 800 °C. The well matched strain and CTE results with literature data show that UV 3D-DIC system is an effective technique for front-surface deformation measurement and has great potential in characterizing deformation response of hypersonic materials and structures subjected to transient aerodynamic heating.     

基于虚拟仪器的空靶通用测试系统的研究

针对空中靶标测试设备现状和问题,提出了一种基于虚拟仪器的新型空靶通用化测试系统,研究了其总体结构和功能特点, 讨论了系统软件体系结构和开发设计。     

飞机复合材料修理中固化技术的探讨

对飞机复合材料固化工艺中热固化、微波固化、电子束固化、紫外光固化等技术的机理和研究现状进行了分析对比。     

Method of the HF wave absorption evaluation based on GIRO network data

High frequency (HF) communication is strongly dependent on the state of the ionosphere, which specifies the mode structure of the radio wave propagating in ionosphere. Another core factor defining the strength of the HF signal at the receiving site is the ionospheric absorption. Accurate modelling the effect of absorption is an essential part of many studies of the HF propagation in the ionosphere.This paper proposes a method for estimating the absorption. The method is based on analysis of vertical sounding ionograms. The main idea of the approach is to compare the main parameters retrieved from measured and simulated ionograms. The combination of Global Ionospheric Radio Observatory (GIRO, http://giro.uml.edu) data and ionograms modelling allows for developing the empiric absorption model available at near real-time. The ionogram simulation taking into account absorption utilizes the NIM-RT (North Ionospheric Model and Ray Tracing) software. As a result, the proposed technique provides more reliable and accurate evaluation of minimum frequency at which echoes are observed in vertical incidence ionosonde soundings. The values of these frequencies should be used in the following simulation to optimize parameters in the empirical formulae for defining absorption HF wave in ionosphere.The ultimate objective of this work is the designing the method, which allows the simulating of HF radio channel accounting for regular absorption due to UV radiation of the Sun. Eventually it could be considered as some kind of the HF propagation forecasting.     

Alpha Particle X-Ray Spectrometer (APXS) on-board Chandrayaan-2 rover

Alpha Particle X-ray Spectrometer (APXS) payload configuration for Chandrayaan-2 rover has been completed recently and fabrication of mechanical assembly, PCB layout design and fabrication are in progress. Here we present the design and performance evaluation of various subsystems developed for APXS payload. The low energy threshold of <1 keV and the energy resolution of ∼150 eV at 5.9 keV, for the Silicon Drift Detector (SDD), as measured from the developed APXS electronics is comparable to the standard spectrometers available off-the-shelf. We have also carried out experiments for measuring fluorescent X-ray spectrum from various standard samples from the USGS catalog irradiated by the laboratory X-ray source ²⁴¹Am with 1 mCi activity. It is shown that intensities of various characteristic X-ray lines are well correlated with the respective elemental concentrations.     

The role of ultraviolet imaging in studies of resolved and unresolved young stellar populations. M31 and M33

We discuss the relevance of UV data in the detection and characterization of hot massive stars and young stellar populations in galaxies. We show results from recent extensive surveys in M31 and M33 with Hubble Space Telescope (HST) multi-wavelength data including UV filters, which imaged several regions at a linear resolution (projected) of less than half a pc in these galaxies, and from GALEX far-UV and near-UV wide-field, low-resolution imaging of the entire galaxies. Both datasets allow us to study the hierarchical structure of star formation: the youngest stellar groups are the most compact, and are often arranged within broader, sparser structures. The derived recent star-formation rates are rather similar for the two galaxies, when scaled for the respective areas. We show how uncertainties in metallicity and type of selective extinction for the internal reddening may affect the results, and how an appropriate complement of UV filters could reduce such uncertainties, and significantly alleviate some parameter degeneracies.