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Published on: April 23, 2018
Turbulence-induced edge image waviness: theory and experiment
M S Belen'kii1, J M Stewart, P Gillespie
1Georgia Institute of Technology, Atlanta, Georgia 30332-0834, USA. mbelenkii@thermotrex.com
Applied Optics
|March 22, 2008
Summary
Atmospheric turbulence causes edge image waviness in ground-to-ground imaging. This study develops a model, identifies angle-of-arrival (AA) angular anisoplanatism as the cause, and presents a mitigation technique reducing waviness variance by 2-3 times.
Area of Science:
- Optical physics
- Atmospheric optics
- Remote sensing
Background:
- Edge image waviness is a phenomenon observed in ground-to-ground imaging systems.
- Understanding the causes and characteristics of this waviness is crucial for accurate image analysis.
- Previous models may not fully capture the complexities of atmospheric effects on image edges.
Purpose of the Study:
- To develop and validate a theoretical model for the edge image waviness effect in ground-to-ground imaging.
- To identify the primary cause of edge image waviness and the relevant atmospheric parameters.
- To develop and implement a method for mitigating edge image waviness.
Main Methods:
- Development of a theoretical model for edge image waviness.
- Validation using Infrared (IR) imagery data from White Sands Missile Range.
- Analysis of angle-of-arrival (AA) angular anisoplanatism and its correlation scale.
- Implementation of a procedure to estimate atmospheric and camera-noise components of image motion.
- Development and validation of an image-averaging technique for waviness mitigation.
Main Results:
- Angle-of-arrival (AA) angular anisoplanatism is identified as the cause of edge image waviness.
- The edge image waviness scale is characterized by the AA correlation scale, not the isoplanatic angle.
- Waviness scale depends on imager angular size and atmospheric outer scale, independent of turbulence strength.
- Spherical divergence of light waves increases the edge waviness scale.
- A mitigation technique reduced edge waviness variance by a factor of 2-3.
- Time history and temporal power spectrum confirmed turbulence as the cause of image motion.
Conclusions:
- The developed theoretical model accurately describes edge image waviness.
- Angle-of-arrival (AA) correlation scale is a key parameter for characterizing edge image waviness.
- The proposed mitigation technique effectively reduces edge image waviness, improving image quality.
- This research provides a deeper understanding of atmospheric turbulence effects on imaging systems.
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