45 research outputs found
How do psychiatrists address delusions in first meetings in acute care? A qualitative study
Licensed under the Creative Commons Attribution Licens
End-to-end numerical simulator of the Shadow Position Sensor (SPS) metrology subsystem of the PROBA-3 ESA mission
PROBA-3 - PRoject for OnBoard Autonomy is an ESA mission to be launched in 2022 where a spacecraſt is used as an external occulter (OSC-Occulter Spacecraſt), to create an artificial solar eclipse as observed by a second spacecraſt, the coronagraph (CSC-Coronagraph Spacecraſt). The two spacecraſts (SCs) will orbit around the Earth, with an highly elliptic orbit (HEO), with the perigee at 600 Km, the apogee at about 60530 Km and an eccentricity of 0.81. The orbital period is of 19.7 hours and the precise formation flight (within 1 mm) will be maintainedforabout6hours overthe apogee, in ordertoguarantee the observation ofthe solarcoronawith the required spatial resolution. The relative alignment ofthe two spacecraſts is obtained bycombining information from several subsystems. One ofthe most accurate subsystem (with accuracy >0.5 mm) is the Shadow Position Sensors (SPS), composed by eight photomultipliers installed around the entrance pupil of the CSC. The SPS will monitor the penumbra generated by the occulter spacecraſt, whose intensity will change according to the relative position ofthe two satellites. A dedicated algorithm has been developed to retrieve the displacementof the spacecraſts fromthe measurements ofthe SPS. Several tests are requiredin ordertoevaluate the robustness of the algorithm and its performances/results for different possible configurations. A soſtware simulator has been developed for this purpose. The simulator includes the possibility to generate synthetic 2-D penumbra profile maps or analyze measured profiles and run different versions ofthe retrieving algorithms, including the
“on-board” version. In order to import the “as built” algorithms, the soſtware is coded using Matlab
Laboratory testbed for the calibration and the validation of the shadow position sensor subsystem of the PROBA3 ESA mission
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PROBA-3 mission and the Shadow Position Sensors: Metrology measurement concept and budget
PROBA-3 is a space mission of the European Space Agency that will test, and validate metrology and control systems for autonomous formation flying of two independent satellites. PROBA-3 will operate in a High Elliptic Orbit and when approaching the apogee at 6·104 Km, the two spacecraft will align to realize a giant externally occulted coronagraph named ASPIICS, with the telescope on one satellite and the external occulter on the other one, at inter-satellite distance of 144.3 m. The formation will be maintained over 6 hrs across the apogee transit and during this time different validation operations will be performed to confirm the effectiveness of the formation flying metrology concept, the metrology control systems and algorithms, and the spacecraft manoeuvring. The observation of the Sun's Corona in the field of view [1.08;3.0]RSun will represent the scientific tool to confirm the formation flying alignment. In this paper, we review the mission concept and we describe the Shadow Position Sensors (SPS), one of the metrological systems designed to provide high accuracy (sub-millimetre level) absolute and relative alignment measurement of the formation flying. The metrology algorithm developed to convert the SPS measurements in lateral and longitudinal movement estimation is also described and the measurement budget summarized
SWELTO - Space WEather Laboratory in Turin Observatory
SWELTO - Space WEather Laboratory in Turin Observatory is a conceptual framework where new ideas for the analysis of space-based and ground-based data are developed and tested. The input data are (but not limited to) remote sensing observations (EUV images of the solar disk, Visible Light coronagraphic images, radio dynamic spectra, etc...), in situ plasma measurements (interplanetary plasma density, velocity, magnetic field, etc...), as well as measurements acquired by local sensors and detectors (radio antenna, fluxgate magnetometer, full-sky cameras, located in OATo). The output products are automatic identification, tracking, and monitoring of solar stationary and dynamic features near the Sun (coronal holes, active regions, coronal mass ejections, etc...), and in the interplanetary medium (shocks, plasmoids, corotating interaction regions, etc...), as well as reconstructions of the interplanetary medium where solar disturbances may propagate from the Sun to the Earth and beyond. These are based both on empirical models and numerical MHD simulations. The aim of SWELTO is not only to test new data analysis methods for future application for Space Weather monitoring and prediction purposes, but also to procure, test and deploy new ground-based instrumentation to monitor the ionospheric and geomagnetic responses to solar activity. Moreover, people involved in SWELTO are active in outreach to disseminate the topics related with Space Weather to students and the general
public