32 research outputs found
Challenge of teaching complex, end-to-end space system design and development process: Earth Observation Satellite System Design training course
The Earth Observation Satellite System Design training course was first offered in 2018 at ESA Academy’s Training and Learning Facility at ESA’s ESEC Galaxia site in Belgium, and again in 2021 in an online format under the Covid-19 pandemic situation. The course covers the end-to-end design and development process of satellite Earth observation systems. Two major challenges were faced by the teaching experts, consisting of the active and retired ESA staff, as well as ESA Academy’s instructional designers for its development: (1) Condensing such a vast subject domain, associated with a complex, multi-disciplinary engineering undertaking, into a compact format (e.g. 4.5 days in 2018) without sacrificing the quality of the essential technical knowledge, engineering practices and logic as taught; (2) Presenting the course materials in a comprehensive form to a group of 30 M.S. and Ph.D. students with their backgrounds generally not covering all of the technical disciplines associated with the course subject domain. The 2021 online edition of the training course, which drew on lessons learnt from 2018, consisted of 18 lectures, plus 5 group project sessions where the students put their acquired knowledge into practice and learned to work in a project team environment. This paper concentrates on the approach and logic adopted by the instructional team to address the above 2 challenges. Difficulties encountered in some of the areas, e.g. remote sensing instrumentation designs, are discusse
Defocusing digital particle image velocimetry and the three-dimensional characterization of two-phase flows
Convective flow field measurement by speckle velocimetry
A 2-D velocity map in a cylindrical Rayleigh-Bénard flow is determined by means of a speckle photography technique. Automatic velocity measurements are performed by two different methods : (i) Isovelocity contours are drawn by spatial filtering; (ii) Local illumination by a laser beam produces Young's fringes which are analysed by an image processing system. New methods are proposed for digital analysis of the speckle fringes.Le champ de vitesse au sein d'une cellule de Rayleigh-Bénard cylindrique est déterminé au moyen d'une technique dérivée de la photographie de speckle. L'analyse des photographies s'effectue automatiquement par deux méthodes différentes : (i) Le filtrage du spectre de fréquences spatiales permet d'obtenir des franges d'égale composante de vitesse; (ii) L'éclairement localisé de la photographie par un faisceau laser produit des franges de Young dont le pas est déterminé au moyen d'un système d'analyse d'image. De nouvelles techniques sont proposées pour l'analyse numérique de ces franges de Young
Measurement and Refinement of Velocity Data Using High Image Density Analysis in Particle Image Velocimetry
Supporting facilities of the airborne imaging spectrometer APEX
The facilities to support the ESA’s airborne APEX hyperspectral mission simulator are described.
These facilities include calibration tools, such as
specific processing in a dedicated Processing and Archiving Facility (PAF), operational calibration and characterization using the Calibration HomeBase (CHB), the In-Flight Characterization facility (IFC) and the Calibration Test Master (CTM).
Further on, a preview on major applications and the corresponding development efforts to provide scientific data products up to level 2/3 to the user are outlined. Products dedicated for the retrieval of limnology, vegetation, atmospheric parameters, as well as general classification routines and rapid mapping tasks are currently under development and prepared for dissemination by the APEX Science Center (ASC) and the APEX Operations
Center (AOC)