Search results for " sensing"
showing 10 items of 1517 documents
RADIOMETRIC CALIBRATION OF A MULTISPECTRAL CAMERA
2006
We describe in detail a method for calibrating a multispectral imaging system based on interference filters. The calibration aims to remove systematic noises introduced by the sensor, and optic and/or filters from multispectral images. After which, we can correct the non-linearity of the sensor response. Systematic noises are measured through a rigorous protocol for acquiring offset, and thermal, and Flat-Field images. The methods for acquiring Flat-Field image, and linearizing sensor response are novel and particularly efficient in the case of a multispectral imaging system. Indeed, in such a system, the reconstruction of a spectrum for each pixel comes from the set of values taken by this…
Prevention of marine pollution from oil spill: The activities of MAPRES project
2008
Maximum and Actual Evapotranspiration for Barley (Hordeum vulgare L.) through NOAA Satellite Images in Castilla-La Mancha, Spain
1996
Abstract An easy-to-follow methodology is developed for the assessment of regional evapotranspiration in Castilla-La Mancha, a semi-arid region of Spain. The methodology is applied to barley crops to monitor the irrigation scheduling over the region, by using remote sensing techniques supplemented by ground measurements. The methodology can be based on either of two models. In the first one, established by Caselles and Delegido, 1 the reference evapotranspiration, ET o , derives from the expression ET o = AR g (T a ) m a x + BR g + C where A, B and C are empirical coefficients, depending on climatic parameters and determined for each region; R g is the daily global radiation; and ( T a ) m …
The miniaturised Mössbauer spectrometer MIMOS IIA: Increased sensitivity and new capability for elemental analysis
2010
The Miniaturised Mossbauer Spectrometers MIMOS II on board the two Mars Exploration Rovers (MER) have now been collecting valuable scientific data for more than five years. Mossbauer Spectrometers are part of two future missions: Phobos Grunt (Russian Space Agency) and a joint ESA—NASA Rover in 2018. The new advanced MIMOS IIA instrument described in this paper uses Silicon Drift Detectors (SDD) allowing also X-ray fluorescence chemical analysis (XRF) simultaneously to Mossbauer acquisitions. This paper highlights the features and technological improvements of the new spectrometer MIMOS IIA.
A innovative semi-immergible USV (SI-USV) drone for marine and lakes operations with instrumental telemetry and acoustic data acquisition capability
2015
The proposed project shows the results obtained in the implementation and testing in lacustrine and marine environment of a nautical remote controlled vehicle with surface navigation and innovative features Semi-Immersible (SI-USV). This vehicle is based on a pending patent belonging to Palermo University (Patent Pending RM2012A000209 and RM2012A000209) concerning innovative semi-immersible vehicles (SI-Drone), that can be remotely controlled from the ground, air, satellite and sea also during the semi-immersible operation. The vehicle with electric power is coupled with a jet propulsion, given the low draft, makes it possible to navigate in shallow waters or coastal shipping or sandbars. T…
The transcriptional activator rfiA is quorum-sensing regulated by cotranscription with the luxI homolog pcol and is essential for plant virulence in …
2009
The gram-negative phytopathogen Pseudomonas corrugata has an acyl-homoserine lactone (AHL) quorum-sensing (QS) system called PcoI/PcoR that is involved in virulence on tomato. This work identifies, downstream of pcol, a gene designated rfiA, which we demonstrate is directly linked to QS by cotranscription with pcol. The deduced RfiA protein contains a DNA-binding domain characteristic of the LuxR family but lacks the autoinducer-binding terminus characteristic of the QS LuxR-family proteins. We also identified, downstream of rfiA, an operon designated pcoABC, encoding for the three components of a tripartite resistance nodulation-cell-division (RND) transporter system. The expression of pco…
Design of a sun tracker for the automatic measurement of spectral irradiance and construction of an irradiance database in the 330-1100 nm range
2007
Abstract An automatic global and direct solar spectral irradiance system has been designed based on two LICOR spectroradiometers equipped with fibre optics and remote cosine sensors. To measure direct irradiance a sun tracker based on step motors has been developed. The whole system is autonomous and works continuously. From the measurements provided by this system a spectral irradiance database in the 330–1100 nm range has been created. This database contains normal direct and global horizontal irradiances as well as diffuse irradiance on a horizontal plane, together with total atmospheric optical thickness and aerosol optical depth.
Spectral optical layer properties of cirrus from collocated airborne measurements – a feasibility study
2015
Abstract. Spectral optical layer properties of cirrus are derived from simultaneous and vertically collocated measurements of spectral upward and downward solar irradiance above and below the cloud layer and concurrent in situ microphysical sampling. From the irradiance data spectral transmissivity, absorptivity, reflectivity, and cloud top albedo of the observed cirrus layer are obtained. At the same time microphysical properties of the cirrus were sampled. The close collocation of the radiative and microphysical measurements, above, beneath and inside the cirrus, is obtained by using a research aircraft (Learjet 35A) in tandem with a towed platform called AIRTOSS (AIRcraft TOwed Sensor Sh…
Optical sensors for ethanol vapor based on polystyrene opals infiltrated with hydrogel
2013
This paper deals with a novel class of optical sensors for ethanol vapor, based on polystyrene opals infiltrated with a hydrogel sensitive to ethanol. Optical characterization of such opals has been performed, proving their effectiveness as sensors