A Passive Ranging Technique for Objects within the Marine Surface Layer

Abstract

Infrared Search and Track (IRST) systems are important to the surface Navy for the detection of low-flying missile threats. Infrared signals propagating within the marine atmospheric surface layer are frequently distorted by strong vertical fluxes. One particular distortion that occurs commonly is the sub-refractive mirage. During sub-refractive mirage conditions, an imaging sensor or camera will record two distinct images of a single point source. A sub-refractive mirage image can be exploited to provide both height and range information. A technique for passive ranging is described, and a case study using field test data is presented as an example of the concept. The primary computational tool chosen for the analysis of refractive effects was a widget-based simulator called IRWarp that predicts refractive effects. IRWarp uses meteorological conditions as input data for a ray-trace module. The ray-trace data are used to generate detailed information about geometrical transformations induced by the propagation environment.

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Document Details

Document Type
Technical Report
Publication Date
Aug 01, 2001
Accession Number
ADA434183

Entities

People

  • Stephen Doss-hammel

Organizations

  • Naval Information Warfare Systems Command

Tags

Communities of Interest

  • Sensors

DTIC Thesaurus Topics

  • Abstracts
  • Algorithms
  • Communication Systems
  • Coordinate Systems
  • Curvature
  • Detectors
  • Elevation
  • Heat Transfer
  • Instructions
  • Isotherms
  • Measurement
  • Radar
  • Range Finding
  • Refractive Index
  • Sea Surface Temperature
  • Surface Temperature
  • Temperature Gradients

Fields of Study

  • Physics

Readers

  • Image Processing and Computer Vision.
  • Sensor Fusion and Tracking Systems.
  • Wave Propagation and Nonlinear Chaotic Dynamics.