Investigation of minimum resolvable temperature difference formulation for polarized thermal imaging range prediction

Download
Author
Guimaraes, Edson F. C.
Date
1999-09Advisor
Cooper, Alfred W.
Pieper, Ron J.
Metadata
Show full item recordAbstract
Previous measurements have demonstrated that a polarization filter can increase ship-background temperature contrast in the infrared, while decreasing the received radiance. Application of this technique to increasing range for detection or recognition of ship targets is being investigated through detection range modeling for a generic FLIR sensor. Laboratory measurements have been made of effective Minimum Resolvable Temperature Difference (MRTD) of a serial-scan 8-12 micrometers sensor for polarized and unpolarized radiation. A variety of standard four-bar target boards of varied spatial frequency and controlled bar-background temperature difference were used to construct MRTD vs. spatial frequency. Results were compared with model predictions using known or measured component parameters for the AGA-780 imager, showing close agreement for observations made by a "trained observer." A modified form of MRTD was developed for a polarized target using a reformulation of the thermal derivative of Planck's law. Modeled and measured values agreed closely for the unpolarized case, and also for both vertically and horizontally polarized cases when the appropriate parameters of the polarization filters were included. Mathematical analysis and measurement agreed in displaying an increase in MRTD with polarization. Predictions of maximum detection and recognition ranges using estimates of polarized effective target-background temperature difference indicated probable range improvement for sea surface degree of polarization in excess of 20%.
Related items
Showing items related by title, author, creator and subject.
-
Modeling second generation FLIR sensor detection recognition and identification range with polarization filtering
Yildirim, Mehmet (Monterey, California. Naval Postgraduate School, 2000-12-01);The influence of polarization filtering on maximum detection, recognition, and identification ranges of a generic second generation FLIR sensor is examined with a computational model. The scenario studied represents a ... -
Polarimetric thermal imaging
Loo, Fook Leong (Monterey California. Naval Postgraduate School, 2007-03);Passive infrared (IR) imagers, using intensity contrast for target detection, are often limited by low target-background contrast. Detecting stationary targets against cluttered backgrounds presents an even bigger challenge. ... -
A polarization analysis of the light emitted by a striated argon discharge
Collins, Richard R. (1966-05);An analysis is made of the 8115A light emitted from the striated positive column of an Argon glow discharge to determine whether or not it is polarized. The procedure consists of separating the perpendicular and parallel ...