Abstract:
A computational ghost imaging apparatus comprising a first electromagnetic radiation source (100) and a control system configured to cause electromagnetic radiation from said first source to be applied to a selected plurality of three-dimensional portions of an atmospheric volume between a second electromagnetic radiation source (110) and object or region of interest (106) so as to heat or ionise the air within said selected portions and create an atmospheric spatial radiation modulator (108) of a specified pattern for causing said object or region of interest to be irradiated with spatially modulated electromagnetic radiation in said specified pattern, the apparatus further comprising a detector for receiving electromagnetic radiation reflected from said object or region of interest (106), and a processing module for reconstructing an image of said object or region of interest using data output by said detector.
Abstract:
Various implementations of the invention compensate for "phase wandering" in tunable laser sources. Phase wandering may negatively impact a performance of a lidar system that employ such laser sources, typically by reducing a coherence length/range of the lidar system, an effective bandwidth of the lidar system, a sensitivity of the lidar system, etc. Some implementations of the invention compensate for phase wandering near the laser source and before the output of the laser is directed toward a target. Some implementations of the invention compensate for phase wandering in the target signal (i.e., the output of the laser that is incident on and reflected back from the target). Some implementations of the invention compensate for phase wandering at the laser source and in the target signal.
Abstract:
Es wird ein Laserscanner (10) angegeben, der einen Lichtsender (12) zum Aussenden eines Lichtsignals (16) in einen Überwachungsbereich (20), einen Lichtempfänger (26) zum Erzeugen eines Empfangssignals aus dem von Objekten in dem Überwachungsbereich (20) remittierten Lichtsignal (22), eine bewegliche Ablenkeinheit (18) zur periodischen Ablenkung des Lichtsignals (16, 22), um im Verlauf der Bewegung den Überwachungsbereich (20) abzutasten, und eine Auswertungseinheit (34) zur Erfassung der Objekte anhand des Empfangssignals und zum Testen des Signalpfads vom Aussenden des Lichtsignals (16) bis zum Erfassen der Objekte aufweist. Dabei ist die Auswertungseinheit (34) dafür ausgebildet, Objekte auch in Winkelstellungen der Ablenkeinheit (18) zu erfassen, in denen der Signalpfad getestet wird.
Abstract:
There are provided methods and systems for producing a wave-beam having substantially constant lateral extent over a desired range of distances, and interrogation and response system and methods utilizing the same. The method for producing a wave-beam having substantially constant lateral extent includes generating a plurality of at least partially incoherent constituent wave-beams having different divergences and directing the plurality constituent wave-beams to propagate along substantially parallel propagation axes such that the constituent wave-beams at least partially overlap and superpose to form a combined wave-beam. The divergences and intensities of the constituent wave-beams are selected such that the combined wave-beam has a desired substantially constant extent over a desired range of distances along said propagation axes.
Abstract:
A calibration method and a distance measurement device thereof based on phase measurement of a double-wavelength laser tube. The method comprises the following steps: step 1, a first wavelength light-wave is transmitted to a target to be measured through a first light filter from a light wave transmitting device during forming an external light path, the light-wave is modulated from a high frequency oscillating signal (S101); step 2, a second wavelength light-wave is transmitted to the receiving device through a second light filter from the light wave transmitting device during forming an internal light path, as an internal light path signal of a basic reference, the second light-wave is generated from the high frequency oscillating signal (S102); step 3, the receiving device compares phases of the two sequentially received light-waves, and output a phase signal eliminated the base reference (S103).