Noise Mechanisms Impacting Micro-Doppler Lidar Signals: Theory and Experiment

Lidar remote sensing of micro-Doppler signals is important for many military applications including characterization and identification of ground and airborne targets (NCTID) and battle damage assessment. The single most important performance metric of these sensors is their velocity measurement precision. The velocity precision of a micro-Doppler lidar is limited by any one of various noise sources, which include shot-noise, local-oscillator frequency noise, speckle decorrelation noise and refractive turbulence piston noise. In this paper, we present a theory, which describes these noise sources and their wavelength dependence. For example, it will be shown that the turbulence piston noise is wavelength independent, while the wavelength dependence of speckle decorrelation noise depends upon whether or not the target is resolved. Furthermore, the noise sources are, to a first-order, independent of the interrogation waveform classification (i.e., pulsed or CW). The results from recent field measurements using a doubletpulse and CW lidar are presented. Form SF298 Citation Data Report Date ("DD MON YYYY") 00042001 Report Type N/A Dates Covered (from... to) ("DD MON YYYY") Title and Subtitle Noise Mechanisms Impacting Micro-Doppler Lidar Signals: Theory and Experiment Contract or Grant Number Program Element Number Authors Gatt, Philip; Henderson, Sammy W.; Thomson, J. Alex; and Hannon, Stephen M. Project Number Task Number Work Unit Number Performing Organization Name(s) and Address(es) Coherent Technologies, Inc. 655 Aspen Ridge Dr. Lafayette, Colorado Performing Organization Number(s) Sponsoring/Monitoring Agency Name(s) and Address(es) Monitoring Agency Acronym Monitoring Agency Report Number(s) Distribution/Availability Statement Approved for public release, distribution unlimited Supplementary Notes Abstract Subject Terms Document Classification unclassified Classification of SF298 unclassified Classification of Abstract unclassified Limitation of Abstract unlimited