Dual-beam potassium Voigt filter for atomic line imaging

Area of Science:

• Remote sensing
• Optical physics
• Spectroscopy

Background:

• Atomic emission features in rocket plumes are difficult to detect due to sunglint interference.
• Spectrally narrowband imaging offers advantages for identifying specific constituents.

Purpose of the Study:

• To demonstrate a dual-beam calibration technique for Voigt magneto-optical filters.
• To improve the calibration of filters for linear polarizers and optical misalignment.
• To enhance the detection of rocket plume constituents.

Main Methods:

• Utilized a Wollaston prism for a dual-beam calibration technique.
• Employed the ElecSus simulation tool and a potassium hollow cathode lamp for filter validation.
• Conducted outdoor testing with a potassium model rocket motor.

Main Results:

• Achieved an RMS error of approximately 2% between filter temperature response and simulation.
• Demonstrated a 20-fold increase in contrast for detecting a potassium model rocket motor.
• Successfully distinguished rocket plume emissions from sunglints.

Conclusions:

• The dual-beam calibration strategy is effective for Voigt magneto-optical filters.
• This technique expands filter field of view while maintaining classification capabilities.
• Enhanced contrast is crucial for accurate remote sensing of rocket plumes.