摘要:
An emission-concentration monitoring system (20)includes first and second monitor stations (22,32) which are separated by a sensing space (40) along a path (28) of a moving vehicle (26). Each station has a source of electromagnetic radiation (64) which is directed through the vehicle's exhaust plume. Each station also has a set of detectors (66) which are positioned to receive the radiation and configured to measure transmittances at wavelengths which are absorbed by molecular species of exhaust plume (e.g., hydrocarbons, nitric oxide, carbon monoxide and carbon dioxide). These sensed transmittances are converted to emission concentrations by a data processor (50) and compared to a set of emission-concentration standards. The vehicle is determined to be in violation only if its emission concentrations at both the first and second monitor stations exceeds the standards. To insure visual identification of the vehicle, images of it are formed at both stations with video cameras (42, 44) and a license plate reader (46). It has been found that the monitoring system improves testing accuracy because the first and second stations essentially form a check against each other to remove errors due, for example, to vehicular temporal variabilities.
摘要:
An unmanned integrated RES 12 integrates all of its components except the reflector 22 into a single console 30 that is positioned at the side of a road and has a CPU 36 that controls calibration, verification and data gathering. The RES's source 32 and receiver 34 are preferably stacked one on top of the other such that the IR beam 24 traverses a low and high path as it crosses the road 14. This allows the RES to detect both low and high ground clearance vehicles. To maintain the vehicle processing and identification throughput, the speed sensor 54 and ALPR 48,50 detect the passing vehicles at steep angles, approximately 20 to 35 degrees. In a preferred system, a manned control center 16 communicates with a large number of the unmanned integrated RES to download emissions data, perform remote diagnostics, and, if necessary, dispatch a technician to perform maintenance on a particular RES.
摘要:
An unmanned integrated RES 12 integrates all of its components except the reflector 22 into a single console 30 that is positioned at the side of a road and has a CPU 36 that controls calibration, verification and data gathering. The RES's source 32 and receiver 34 are preferably stacked one on top of the other such that the IR beam 24 traverses a low and high path as it crosses the road 14. This allows the RES to detect both low and high ground clearance vehicles. To maintain the vehicle processing and identification throughput, the speed sensor 54 and ALPR 48,50 detect the passing vehicles at steep angles, approximately 20 to 35 degrees. In a preferred system, a manned control center 16 communicates with a large number of the unmanned integrated RES to download emissions data, perform remote diagnostics, and, if necessary, dispatch a technician to perform maintenance on a particular RES.
摘要:
An unmanned integrated RES 12 integrates all of its components except the reflector 22 into a single console 30 that is positioned at the side of a road and has a CPU 36 that controls calibration, verification and data gathering. The RES's source 32 and receiver 34 are preferably stacked one on top of the other such that the IR beam 24 traverses a low and high path as it crosses the road 14. This allows the RES to detect both low and high ground clearance vehicles. To maintain the vehicle processing and identification throughput, the speed sensor 54 and ALPR 48,50 detect the passing vehicles at steep angles, approximately 20 to 35 degrees. In a preferred system, a manned control center 16 communicates with a large number of the unmanned integrated RES to download emissions data, perform remote diagnostics, and, if necessary, dispatch a technician to perform maintenance on a particular RES.
摘要:
A method and apparatus for sensing a composition of an exhaust plume includes a light source that radiates an infrared light beam having a plurality of predetermined wavelengths. A first of the predetermined wavelengths is associated with carbon dioxide and a second of the predetermined wavelengths is associated with a second gas, such as a hydrocarbon or carbon monoxide. The apparatus also includes a detector unit that detects the beam passing through the plume. The apparatus computes a ratio of the second gas to carbon dioxide based upon the first and second detected wavelengths, and this ratio is then multiplied by a predetermined estimation of a concentration of carbon dioxide in the plume.
摘要:
A light source radiates an infrared beam that passes through a chopper, a calibration cell and the exhaust plume of a motor vehicle passing in front of the source. A photosensor assembly includes a plurality of photodetectors which are spaced closely adjacent to each other and simultaneously sense the beam after it propagates through the plume. An optical beam homogenizer or integrator disposed between the plume and the photosensor unit causes the light incident on the photodetectors to have uniform intensity. The photodetectors are sensitive to different wavelengths corresponding to spectral absorption peaks of constituents of the composition of the plume, including carbon monoxide (CO), carbon dioxide (CO.sub.2), hydrocarbon (HC), water vapor (H.sub.2 O) and nitric oxide (NO). A computer computes the composition of the plume as the percentages of the constituents based on the sensed transmittances of the respective wavelengths through the plume. A video camera produces a video image of the vehicle license plate, which is displayed on a video monitor and recorded on a video recorder together with the plume composition data.
摘要:
A 3D ultraviolet (UV) imaging LADAR system includes a UV source configured to generate a UV interrogation beam, a sensor configured to receive a UV return beam reflected from a target and to produce an electrical signal, and an imaging module coupled to the sensor and configured to receive the electrical signal and to generate a corresponding 3D image of the target. In one example, the sensor includes a down-shifting device configured to down-shift the UV return beam to a down-shifted light beam of a different wavelength, for example, in the visible or SWIR wavelength ranges.
摘要:
An integrated infrared and millimeter-wave monolithic focal plane sensor array having a substrate upon which an integrated array of infrared sensors and mm-wave sensors are provided at a first planar level on the same side of the substrate, and a planar antenna for receiving incident millimeter-wave radiation located at a second planar level located between the integrated array of sensors and the surface of the substrates for coupling the mm-wave radiation field to the mm-wave sensor. The antenna receiver of electromagnetic radiation, in one embodiment, is an antenna having a crossed bowtie configuration which efficiently couples the radiation field to the mm-wave sensor. The invention also is directed to a method of fabricating such a radiation sensor.
摘要:
An imaging device (10) has a plurality of unit cells that contribute to forming an image of a scene. The imaging device includes a layer of semiconductor material (16), for example silicon, that has low noise photogate charge-mode readout circuitry (20, 21, 26, 28) (e.g., CCD or CMOS readout circuitry and structures) that is disposed upon a first surface (18) of the layer. A second, opposing surface of the layer is a radiation admitting surface of the layer. The layer has a bandgap selected for absorbing electromagnetic radiation having wavelengths shorter than about one micrometer and for generating charge carriers from the absorbed radiation. The generated charge carriers are collected by the photogate charge-mode readout circuitry. A thermal sensing element (22) is disposed above and is thermally isolated from the first surface of the layer. The thermal sensing element may be, by example, one of a bolometer element, a pyroelectric element, or a thermopile element. A layer (12) of narrower bandgap semiconductor material can also be employed with this invention, wherein the layer of narrower bandgap semiconductor material (such as InGaAs or HgCdTe) is atomically bonded to the second surface along a heterojunction interface that is continuous or apertured across the second surface. The bonded layer is used to absorb NIR and visible light.
摘要:
A highly integrated thermal sensor (10) is responsive to radiation having wavelengths within a predetermined band of wavelengths. The sensor, which may be a thermopile, is comprised of a substrate (16) comprised of at least one semiconductor material. The substrate includes at least one active region disposed within a first surface of the substrate. The sensor further includes a plurality of thermally-responsive junctions (HJ, CJ) between dissimilar materials (22, 24) that are disposed within the at least one active region, wherein at least one of the thermally-responsive junctions is a hot junction. The hot junction is thermally isolated from the substrate by being suspended from the substrate on dielectric bridges or, in another embodiment, by a thermally insulating and patterned polymer. In a backside illuminated embodiment of this invention the sensor further includes an optical cavity (26) formed within a second surface of the substrate in registration with the active region. The optical cavity includes a radiation absorbing region (28) that is thermally coupled to the at least one hot junction. The sensor further includes an optical filter (30) that is disposed over the optical cavity for admitting radiation within the predetermined band of wavelengths into the optical cavity for absorption by the radiation absorbing region.