Search results for " view"
showing 10 items of 337 documents
PERSPECTIVE RESTITUTION FROM VIEW CAMERAS PHOTOS
2022
Abstract. The paper aims at discussing the accuracy of perspective restitution from view camera photos; view cameras are non-standard cameras frequently used in the past century for on field shooting of buildings and urban sites; this is why the reconstruction of lost buildings often deals with photos taken with a view camera. The case study chosen for the proposed experiment is an urban complex built in Palermo in the ‘50s. The site features a very regular layout with surfaces at right angle, that supports the graphic reconstruction of photos’ inner and outer orientation. The site has been surveyed with a laser scanner; the point cloud provided the metric information needed for the evaluat…
Technology as 'Applied Science': a Serious Misconception that Reinforces Distorted and Impoverished Views of Science
2005
The current consideration of technology as "applied science", this is to say, as something that comes "after" science, justifies the lack of attention paid to technology in science education. In our paper we question this simplistic view of the science-tecnology relationship, historically rooted in the unequal appreciation of intellectual and manual work, and we try to show how the absense of the technological dimension in science education contributes to a naive and distorted view of science which deeply affects the necessary scientific and technological literacy of all citizens. Fil: Gil Perez, Daniel. Universidad de Valencia; España Fil: Vilches, Amparo. Universidad de Valencia; España F…
Une objectivité kaléidoscopique : construire l'image scientifique du monde
2011
article accepté par la revue Philosophie, en cours de publication, date de publication provisoire; National audience
ARGO-YBJ constraints on very high energy emission from GRBs
2009
The ARGO-YBJ (Astrophysical Radiation Ground-based Observatory at YangBaJing) experiment is designed for very high energy $\gamma$-astronomy and cosmic ray researches. Due to the full coverage of a large area ($5600 m^2$) with resistive plate chambers at a very high altitude (4300 m a.s.l.), the ARGO-YBJ detector is used to search for transient phenomena, such as Gamma-ray bursts (GRBs). Because the ARGO-YBJ detector has a large field of view ($\sim$2 sr) and is operated with a high duty cycle ($>$90%), it is well suited for GRB surveying and can be operated in searches for high energy GRBs following alarms set by satellite-borne observations at lower energies. In this paper, the sensitivit…
OMC: An Optical Monitoring Camera for INTEGRAL
2003
The Optical Monitoring Camera (OMC) will observe the optical emission from the prime targets of the gamma- ray instruments onboard the ESA mission INTEGRAL, with the support of the JEM-X monitor in the X-ray domain. This capability will provide invaluable diagnostic information on the nature and the physics of the sources over a broad wavelength range. Its main scientific objectives are: (1) to monitor the optical emission from the sources observed by the gamma- and X-ray instruments, measuring the time and intensity structure of the optical emission for comparison with variability at high energies, and (2) to provide the brightness and position of the optical counterpart of any gamma- or X…
OMC: An Optical Monitoring Camera for INTEGRAL
1998
The INTEGRAL payload has been designed to study simultaneously gamma-ray sources in a wide field of view over many decades in energy (around 2 eV + 4 keV − 20 MeV) and thus make a major contribution to short time-scale high-energy astrophysics. The OMC will observe the optical emission from the prime targets of the gamma-ray instruments with the support of the x-ray monitor. This capability will provide invaluable diagnostic information on the nature and the physics of the sources over a broad wavelength range. The main scientific objectives will be: (1) to monitor the optical emission from the sources observed by the gamma- and x-ray instruments, measuring the time and intensity structure …
The wide field imager for the International X-ray Observatory
2009
The large collecting area of the X-ray optics on the International X-ray Observatory (IXO), their good angular resolution, the wide bandwidth of X-ray energies and the high radiation tolerance required for the X-ray detectors in the focal plane have stimulated a new development of devices which unify all those science driven specifications in one single detector. The concept of a monolithic, back-illuminated silicon active pixel sensor (APS) based on the DEPFET structure is proposed for the IXO mission, being a fully depleted, back-illuminated 450 μm thick detector with a physical size of about 10 × 10 cm 2 corresponding to the 18 arcmin field of view. The backside will be covered with an i…
The X-ray Integral Field Unit (X-IFU) for Athena
2014
Athena is designed to implement the Hot and Energetic Universe science theme selected by the European Space Agency for the second large mission of its Cosmic Vision program. The Athena science payload consists of a large aperture high angular resolution X-ray optics (2 m2 at 1 keV) and twelve meters away, two interchangeable focal plane instruments: the X-ray Integral Field Unit (X-IFU) and the Wide Field Imager. The X-IFU is a cryogenic X-ray spectrometer, based on a large array of Transition Edge Sensors (TES), oering 2.5 eV spectral resolution, with approximately 5" pixels, over a field of view of 5' in diameter. In this paper, we present the X-IFU detector and readout electronics princi…
Calibration and Simulation of the GRB trigger detector of the Ultra Fast Flash Observatory
2013
The UFFO (Ultra-Fast Flash Observatory) is a GRB detector on board the Lomonosov satellite, to be launched in 2013. The GRB trigger is provided by an X-ray detector, called UBAT (UFFO Burst Alarm & Trigger Telescope), which detects X-rays from the GRB and then triggers to determine the direction of the GRB and then alerts the Slewing Mirror Telescope (SMT) to turn in the direction of the GRB and record the optical photon fluxes. This report details the calibration of the two components: the MAPMTs and the YSO crystals and simulations of the UBAT. The results shows that this design can observe a GRB within a field of view of ±35° and can trigger in a time scale as short as 0.2 – 1.0 s af…
Magnetic shielding of soft protons in future X-ray telescopes: the case of the ATHENA Wide Field Imager
2018
Both the interplanetary space and the Earth magnetosphere are populated by low energy ($\leq300$ keV) protons that are potentially able to scatter on the reflecting surface of Wolter-I optics of X-ray focusing telescopes and reach the focal plane. This phenomenon, depending on the X-ray instrumentation, can dramatically increase the background level, reducing the sensitivity or, in the most extreme cases, compromising the observation itself. The use of a magnetic diverter, deflecting protons away from the field of view, requires a detailed characterization of their angular and energy distribution when exiting the mirror. We present the first end-to-end Geant4 simulation of proton scattering…