Search results for "Remote Sensing"
showing 10 items of 1262 documents
JEM–X inflight performance
2003
We summarize the inflight performance of JEM-X, the X-ray monitor on the INTEGRAL mission during the initial ten months of operations. The JEM-X instruments have now been tuned to stable operational conditions. The performance is found to be close to the pre-launch expectations. The ground calibrations and the inflight calibration data permit to determine the instruments characteristics to fully support the scientific data analysis. Reglero Velasco, Victor, Victor.Reglero@uv.es ; Martinez Nuñez, Silvia, Silvia.Martinez@uv.es
Retrieval of sun-induced fluorescence using advanced spectral fitting methods
2015
Abstract The FLuorescence EXplorer (FLEX) satellite mission, candidate of ESA's 8th Earth Explorer program, is explicitly optimized for detecting the sun-induced fluorescence emitted by plants. It will allow consistent measurements around the O2-B (687 nm) and O2-A (760 nm) bands, related to the red and far-red fluorescence emission peaks respectively, the photochemical reflectance index, and the structural-chemical state variables of the canopy. The sun-induced fluorescence signal, overlapped to the surface reflected radiance, can be accurately retrieved by employing the powerful spectral fitting technique. In this framework, a set of fluorescence retrieval algorithms optimized for FLEX ar…
On the Accuracy of the Backward Hemispheric Integrating Nephelometer
1976
Abstract Modified integrating nephelometers are used to measure backward hemispheric scattering coefficients together with total scattering coefficients. These parameters yield information about the chemical nature of the aerosol particles in certain situations involving relatively pure compounds. They are also used as input parameters in climatic models. In this study the effects of the three angular truncations in the modified integrating nephelometers are investigated. We provide a quantitative base to be used with these instruments to determine hemispheric backscatter of aerosol particles and its relationship to the total scattering coefficient.
The atmospheric nightglow in the 300– wavelength
2002
Abstract The balloon-borne experiment, named BAckground BYpass (BABY) belongs to a wider program that has as its final goal the detection and study of high-energy cosmic rays from space (satellite, Space Station). An information of fundamental importance for this class of projects concerns the nighttime background light. The instrument designed to detect fluorescence photons is basically composed of two collimated photomultipliers: a single photon-counting PMT and a charge integration PMT. We briefly report the details of the design, operation and performance of the detector, which was designed and completely built at the IFCAI–CNR Institute in Palermo. Preliminary analysis and results of t…
Layout and performance of RPC used in the Argo-YBJ experiment
2006
The layout of the RPCs, used in the Argo-YBJ experiment to image with a high space-time granularity the atmospheric shower, is described in this paper. The detector has been assembled to provide both digital and analog informations in order to cover a wide particle density range with a time accuracy of 1 ns. The experimental results obtained operating the chambers in streamer mode at sea level with a standard gas mixture are presented. (c) 2006 Elsevier B.V. All rights reserved.
A coded mask for γ-ray astronomy. Design and calibration
2003
Abstract The high-resolution γ-ray spectrometer (SPI) is one of the two main instruments on board the ESA INTEGRAL satellite successfully launched in October 2002. SPI uses coded aperture mask technique in order to have imaging capabilities at the energy band (20 keV–8 MeV) it will study celestial sources. The SPI imaging performance depends critically on the quality of the coded mask response and also on the precise knowledge of such response function. In this paper we present a general description of the SPI Coded Mask design together with its main features. Scientific impact of INTEGRAL SPI Coded Mask design on the instrument capabilities is also discussed. Results obtained for Mask cali…
Atmospheric Background Measurement in the 300–400 nm Band with a Balloon Borne Experiment during a Nocturnal Flight
2001
The balloon borne experiment, named BABY (BAckground BYpass) belongs to a wider program, AIRWATCH-OWL, intended for the observation of high energy Cosmic Rays from space, detecting the faint UV fluorescence light emitted by the atmospheric Nitrogen as final result of a complex hadronic cascade. In this framework, one of the fundamental information concern the knowledge of the background level. This is one of the main parameters that contribute to the sensitivity of any kind of instrument. The apparatus used for the BABY experiment was designed and completely built at the IFCAI-CNR in Palermo. The instrument is composed by two filtered and collimated photomultipliers (PMT) that detect the UV…
Photon Pressure Force on Space Debris TOPEX/Poseidon Measured by Satellite Laser Ranging
2017
The TOPEX/Poseidon (T/P) altimetry mission operated for 13 years before the satellite was decommissioned in January 2006, becoming a large space debris object at an altitude of 1,340 km. Since the end of the mission, the interaction of T/P with the space environment has driven the satellite's spin dynamics. Satellite Laser Ranging (SLR) measurements collected from June 2014 until October 2016 allow for the satellite spin axis orientation to be determined with an accuracy of 1.7°. The spin axis coincides with the platform yaw axis (formerly pointing in the nadir direction) about which the body rotates in a counterclockwise direction. The combined photometric and SLR data collected over the 1…
ARCADE: Description of the project and setup of the Lidar/AMT system
2015
The ARCADE (Atmospheric Research for Climate and Astroparticle DEtection) project is a 3 years project funded by MIUR, that aims to study the aerosol attenuation of UV light in atmosphere using multiple instruments and techniques, as those commonly used in the cosmic rays community: elastic Lidar, Raman Lidar, side-scattering measurements using a distant laser source. All measurements will be acquired on the same air mass at the same time, in a semi-desertic site near Lamar, Colorado (U.S.). For each instrument, multiple analysis techniques will be tested: the target is a better comprehension of the systematics and limits of applicability of each method. The system is composed by a Lidar (e…
FRAM—The Robotic Telescope for the Monitoring of the Wavelength Dependence of the Extinction: Description of Hardware, Data Analysis, and Results
2010
FRAM-F/(Ph)otometric Robotic Atmospheric Monitor is one of the atmospheric monitoring instruments at the Pierre Auger Observatory in Argentina. FRAM is an optical telescope equipped with CCD cameras and photometer, and it automatically observes a set of selected standard stars. Primarily, FRAM observations are used to obtain the wavelength dependence of the light extinction. FRAM telescope is also able to observe secondary astronomical targets, and namely the detection of optical counterparts of gamma-ray bursts has already proven to be successful. Finally, a wide-field CCD camera of FRAM can be used for rapid monitoring of atmospheric conditions along the track of particularly interesting …