Accession Number : ADA329046

Title :   Modelocked-Laser Laser Radar Performance in the Detection of TMD and NMD Targets,

Corporate Author : SCHAFER (W J) ASSOCIATES INC CHELMSFORD MA

Personal Author(s) : Youmans, Douglas G. ; Robertson, Rodney

PDF Url : ADA329046

Report Date : 1997

Pagination or Media Count : 12

Abstract : Ultra compact mode locked CO2 lasers and mode locked Nd:fiber lasers are being developed for Theater Missile Defense (TMD) and National Missile Defense (NMD) applications. These lasers produce a coherent train of narrow pulses which may be used in a coherent laser radar (ladar) to form an image of a possible target. The distance to the target is irrelevant as long as there is enough received energy. These images are known as range Doppler, range resolved Doppler, or inverse synthetic aperture radar (ISAR) images. The down range image resolution is given by the micro pulse width multiplied by c/2, and the image Doppler resolution is given by the reciprocal total pulse length consisting of many hundreds of micro pulses. In this paper we briefly review previous work on the target range Doppler image features which are useful for target discrimination, and then we examine the detection of the target under low signal conditions given passive sensor or radar handover range and velocity information which contains errors. A Gaussian mode radiometry analysis is presented, the range Doppler image formation process is reviewed, and the effects of target speckle, pointing errors, and atmospheric turbulence are discussed. A metric for determining a target detection, under these low signal initial conditions, is proposed.

Descriptors :   *GUIDED MISSILE DETECTION, *MODE LOCKED LASERS, *THEATER MISSILE DEFENSE, SIGNAL PROCESSING, OPTICAL RADAR, PASSIVE SYSTEMS, TARGET DISCRIMINATION, SYNTHETIC APERTURE RADAR, RADAR IMAGES, LASER BEAMS, CARBON DIOXIDE LASERS, NEODYMIUM LASERS, COHERENT RADAR.

Subject Categories : Lasers and Masers
      Antimissile Defense Systems
      Active & Passive Radar Detection & Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE