摘要:
A reader geometry visualization tool for a geo-location system technician's personal computer is operative to display a map of an asset management environment. The technician interactively places and manipulates a distribution of tag transmission readers and any potential impairments to RF transmissions on the map. The locations of the readers (and any impairments) are coupled as input parameters to a mathematical model of a tag-based geo-location system. The performance of the map-parameterized geo-location system model is then computed as a geometric dilution of precision (gdop) value for the intended object coverage area. The computed (gdop) performance is visually characterized on the displayed map, as by way of different colors to indicate how accurately the proposed reader geometry will enable the system to locate objects anywhere in the coverage area.
摘要:
Example embodiments are directed to various aspects of processing received signals for determining a location of a source of the signals. An example method may include generating signal timing information, and determining times for a plurality of window periods for the signal of interest based on the signal timing information. The example method may also include retrieving, from a memory device that stores the signal stream, symbols of the signal of interest based on the window periods, and formatting the symbols of the signal of interest in preparation for determining a location of a source of the signal of interest. Additional and alternative methods and apparatuses are also provided.
摘要:
A location system for tracking assets within a terminal includes a Differential Global Positioning System (DGPS) reference receiver within the terminal that receives GPS signals and generates DGPS correction data. In one aspect, a roving receiver unit is carried by an asset to be tracked within the terminal. It includes a GPS receiver that receives GPS signals and the DGPS correction data from the DGPS reference receiver. A tag transmitter transmits a wireless RF signal containing GPS location data based on received GPS signals and DGPS correction data. At least one access point is positioned within the terminal for receiving the wireless RF signal from the tag transmitter. A processor is operatively connected to the at least one access point for receiving GPS location data and determining a location of the asset to be tracked.
摘要:
A location system for tracking assets within a terminal includes a Differential Global Positioning System (DGPS) reference receiver within the terminal that receives GPS signals and generates DGPS correction data. In one aspect, a roving receiver unit is carried by an asset to be tracked within the terminal. It includes a GPS receiver that receives GPS signals and the DGPS correction data from the DGPS reference receiver. A tag transmitter transmits a wireless RF signal containing GPS location data based on received GPS signals and DGPS correction data. At least one access point is positioned within the terminal for receiving the wireless RF signal from the tag transmitter. A processor is operatively connected to the at least one access point for receiving GPS location data and determining a location of the asset to be tracked.
摘要:
Example embodiments are directed to various aspects of processing received signals for determining a location of a source of the signals. An example method may include generating signal timing information, and determining times for a plurality of window periods for the signal of interest based on the signal timing information. The example method may also include retrieving, from a memory device that stores the signal stream, symbols of the signal of interest based on the window periods, and formatting the symbols of the signal of interest in preparation for determining a location of a source of the signal of interest. Additional and alternative methods and apparatuses are also provided.
摘要:
A system and method for identifying objects within a monitored environment includes a plurality of tag signal readers contained within the monitored environment and serially connected along a single connection line as a coaxial cable for receiving tag signals from at least one tag contained within the monitored environment. The tagged signals received by tag signal readers are timed and associated with a particular tag signal reader, such as by the use of multiplexing techniques. A location processor is connected to the single connection line and determines which tag signals are first-to-arrive signals and conduct differentiation of the first-to-arrive signals to locate a tag.
摘要:
A method and system for detecting concealed weapons and explosives by imaging THz scenes using conventional optics and detectors is provided. Photon fields with two different wavelengths can be sent through a chopper and towards a wavelength-selective mirror. A light beam with a wavelength in the visible or IR range is sent toward a visible photon array detector. Similarly, light beams with wavelengths in the THz range can be sent towards a target, which are reflected and/or absorbed by objects in the target. The reflected or transmitted light continues on through an optional filter to remove background light, then into a non-imaging detector. The visible photon array detector can be coupled with the non-imaging detector, which will register an image of the scene that is illuminated by the THz photons.
摘要:
Coherent transfer of laser energy between laser fields with high efficiency (85-95%) is obtained by energy coupling of nearly copropagating (intersecting) laser beams in mono-atomic vapor and provides an output beam of high power when nearly equal energy pulses are tuned near resonance with the transition of the atom of the vapor (e.g., potassium vapor at 230.degree.-260.degree. C.). The frequencies of the beams differ by approximately the inverse of the excited state lifetime of the atoms for optimum combining (coupling efficiency).
摘要:
Distortion introduced into a multiamplitude signal format by a high power microwave amplifier is compensated by a system which adapts itself to non-linearities present in the amplifier and predistorts the input signals before they are subjected to the non-linearities created by the amplifier. The degree of predistortion is non-fixed and varies or is updated as the non-linear conversion characteristics of the amplifier change with time.
摘要:
Various methods for modeling timing relationships between clocks are provided. One example method includes identifying a link that is one of a plurality of links within a wireless locating system and receiving link data describing a reference signal event for the link. The example method may also include determining a reliability metric for the link based on the link data and comparing the reliability metric to a threshold reliability metric to determine whether the link is a reliable link. Further, the example method may include adding the link to a collection of reliable links for the wireless locating system, and generating a model describing a timing relationship between respective clocks of each of a plurality of receiver units in the wireless locating system based on link data for each of the reliable links. Related systems and apparatuses are also provided.