Abstract:
A system for surveillance of a delimited area within which people move, wherein at least one hollow optical fiber is configured for extending through the area and is provided throughout its length with a plurality of holes that set an internal channel of the fiber in communication with the outside of the fiber itself. There is provided an optical source configured for supplying the optical signal to one end of the hollow optical fiber and a sensor designed to detect at one end of the hollow optical fiber the optical signal transmitted throughout the length of the fiber itself. A processing unit is configured for examining the spectrum of the optical signal detected by the sensors in order to detect the presence of toxic agents present in the area and drawn into said channel.
Abstract:
An apparatus for processing an optical signal of a spectrometer using sparse nature of a signal spectrum is provided including an optical filter array configured to filter an incident light, an optical sensor array configured to convert the filtered light into charges and a digital signal processing unit configured to perform a digital signal processing on an output from the optical sensor array on the basis of an L1 norm minimization algorithm using sparse nature of a signal spectrum and recover spectrum information of the incident light.
Abstract:
A method of multispectral decomposition for the removal of out-of-band effects. A band of a multispectral radiance is measured using at least one optical filter, upon scanning a plurality of original radiances. A spectral range of an integral is partitioned between a maximum cut-off wavelength of the band and a minimum cut-off wavelength of the band into a plurality of sub-ranges. A multispectral radiance vector is generated from the measured band-averaged spectral radiances. The pre-calculated multispectral decomposition transform matrix corresponding to the optical filter and the measured multispectral radiance vector are matrix-multiplied to generate a band-averaged spectral radiances image vector representing a plurality of recovered band-averaged spectral radiances. The plurality of recovered band-averaged spectral radiances is outputted, for example to a display, thereby generating a plurality of recovered radiances free of out-of-band effects and which approximate the plurality of original radiances.
Abstract:
Methods of optimizing the diameters of nanowire photodiode light sensors. The method includes comparing the response of nanowire photodiode pixels having predetermined diameters with standard spectral response curves and determining the difference between the spectral response of the photodiode pixels and the standard spectral response curves. Also included are nanowire photodiode light sensors with optimized nanowire diameters and methods of scene reconstruction.
Abstract:
A detection system comprising detection processing means, spectral discrimination means, and temporal tracking and declaration processing means which cooperate to detect and declare a missile launch. A spatial filter isolates discrete spectral features in an image from a detector array. The discrete spectral features must pass a threshold, which may be adaptive. In a spectral discrimination step, the pixel-to-pixel separation for those pixels passing the spatial filter step is compared to a predetermined pixel spacing. The predetermined pixel spacing is determined from the optical setup and a spectral feature of interest that is contained within the emission from, for example, an ignited rocket motor or other fired projectile. In a temporal step, the pixels that have met the other criteria are tracked as candidate detections, which are declared a threat if they display characteristics of a moving threat, e.g., a MANPADS missile, RPG, mortar or the like.
Abstract:
A multispectral imaging color measurement system, comprising a dark room, a sample platform and an imaging device for capturing said object being measured; a controllable illumination device, a filter wheel unit, an imaging signal processing unit and an electronic control unit. A method for processing imaging signals of the multispectral imaging color measurement is also proposed. The multispectral imaging color measurement system and the method for processing imaging signals thereof can overcome the inaccuracy of traditional digital imaging systems and the limits of spectrophotometer systems and provide users in the textile industry with highly accurate color measurement and evaluation.
Abstract:
Calibration of an arbitrary spectrometer can use a stable monolithic interferometer as a wavelength calibration standard. Light from a polychromatic light source is input to the monolithic interferometer where it undergoes interference based on the optical path difference (OPD) of the interferometer. The resulting wavelength-modulated output beam is analyzed by a reference spectrometer to generate reference data. The output beam from the interferometer can be provided to an arbitrary spectral instrument. Wavelength calibration of the arbitrary spectral instrument may then be performed based on a comparison of the spectral instrument output with the reference data. By appropriate choice of materials for the monolithic interferometer, a highly stable structure can be fabricated that has a wide field and/or is thermally compensated. Because the interferometer is stable, the one-time generated reference data can be used over an extended period of time without re-characterization.
Abstract:
In a color imaging system, multiple rendering devices are provided at different nodes along a network. Each rendering device has a color measurement instrument for calibrating the color presented by the rendering device. A rendering device may be a printer in which the measuring of color samples on a sheet rendered by the printer is provided by a sensor coupled to a transport mechanism which moves the sensor and sheet relative to each other, where the sensor provides light from the samples to a spectrograph. A rendering device may also be a display having a member supporting a color measuring instrument for receiving light from an area of the screen. The color measuring instruments provide for non-contact measurements of color samples rendered on a display or a sheet, and are self calibrating by the use of calibration references.
Abstract:
The invention relates to a miniaturized spectrometer for investigating the spectrum of emission radiation excited in an object by incident radiation. For the miniaturized spectrometer according to the invention, a diode laser is preferably used as an edge emitter (without a perforated shutter). The window of the edge emitter is arranged at the focal point of the converging lens at the input of the illuminating beam path (without an optical fiber), preferably without a perforated shutter. The edge emitter produces a divergent beam pencil with an elliptical cross-section. The length ratio of the main axes of the ellipse is more than 2:1. The large main axis of the ellipse runs parallel to the longitudinal axis of the entry slit of the microspectrometer.
Abstract:
A method of preparing nanothin polymer films having uniform and selectively sized pores utilizing pore forming templates. Lipids and pore forming templates are dissolved into a first solution. The solvent is removed thereby creating a lipid bilayer with pore forming templates dispersed throughout. The bilayer is hydrated and monomers and crosslinkers are added to create a second solution. A nanothin film with pore forming templates is created through polymerization of said second solution. The pore forming templates are dissolved into a third solution by addition of a chemical in which the pore forming template is soluble, but the lipid bilayer is insoluble. This third solution is separated from the mixture leaving a nanothin polymer film with pores of a uniform thickness and surface area. In summary, the guided assembly method presented here suggests a new general strategy for the fabrication of nanothin materials with controlled permeability, which provides improvements over the currently existing technology.