Accession Number : ADA528772


Title :   Terahertz Inverse Synthetic Aperture Radar (ISAR) Imaging With a Quantum Cascade Laser Transmitter


Descriptive Note : Journal article


Corporate Author : NATIONAL GROUND INTELLIGENCE CENTER CHARLOTTESVILLE VA


Personal Author(s) : Danylov, Andriy A ; Goyette, Thomas M ; Waldman, Jerry ; Coulombe, Michael J ; Gatesman, Andrew J ; Giles, Robert H ; Qian, Xifeng ; Chandrayan, Neelima ; Vangala, Shivashankar ; Termkoa, Krongtip ; Goodhue, William D ; Nixon, William E


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a528772.pdf


Report Date : Jan 2010


Pagination or Media Count : 10


Abstract : A coherent transceiver using a THz quantum cascade (TQCL) laser as the transmitter and an optically pumped molecular laser as the local oscillator has been used, with a pair of Schottky diode mixers in the receiver and reference channels, to acquire high-resolution images of fully illuminated targets, including scale models and concealed objects. Phase stability of the received signal, sufficient to allow coherent image processing of the rotating target (in azimuth and elevation), was obtained by frequency-locking the TQCL to the free-running, highly stable optically pumped molecular laser. While the range to the target was limited by the available TQCL power (several hundred microwatts) and reasonably strong indoor atmospheric attenuation at 2.408 THz, the coherence length of the TQCL transmitter will allow coherent imaging over distances up to several hundred meters. Image data obtained with the system is presented.


Descriptors :   *SYNTHETIC APERTURE RADAR , *IMAGE PROCESSING , SEMICONDUCTORS , LASERS , TRANSMITTERS , SCHOTTKY BARRIER DEVICES , ATMOSPHERIC ATTENUATION , TRANSMITTER RECEIVERS , LOCAL OSCILLATORS , MIXERS(ELECTRONICS) , OPTICAL PUMPING , MOLECULAR LASERS , QUANTUM THEORY , COHERENT ELECTROMAGNETIC RADIATION , REPRINTS


Subject Categories : Lasers and Masers
      Miscellaneous Detection and Detectors
      Active & Passive Radar Detection & Equipment
      Quantum Theory and Relativity


Distribution Statement : APPROVED FOR PUBLIC RELEASE