Extended-field large-aperture interferometer-spectrometer for airglow surveys.

Area of Science:

• Atmospheric physics and optics
• Spectroscopy
• Aeronomy

Background:

• Airglow emissions provide crucial data on atmospheric processes.
• Conventional spectrometers have limitations in throughput and field of view for sky surveys.
• Interferometry offers potential for high-throughput spectral measurements.

Purpose of the Study:

• To design and present a field-of-view-widened interferometer for enhanced airglow surveys.
• To demonstrate the instrument's performance with preliminary airglow data.
• To investigate atmospheric emissions in the visible spectrum.

Main Methods:

• Utilized a 4.5-cm aperture interferometer with optical wedge compensators to widen the field of view.
• Employed digital recording for high dynamic range and Fast Fourier Transform (FFT) computation.
• Acquired airglow spectra (0.6-0.9 µm, ~2 Å resolution) of the midlatitude sky.

Main Results:

• Achieved a field-widened throughput gain of approximately 100x compared to a standard Michelson interferometer.
• Presented airglow spectra during sunset transition and nighttime.
• Identified prominent hydroxyl emission bands and oxygen red lines.
• Observed enhanced emissions during twilight and potential vibrationally excited O2.

Conclusions:

• The field-of-view-widened interferometer significantly improves airglow survey efficiency.
• The instrument successfully captured detailed spectra of key atmospheric emissions.
• Preliminary results suggest potential for new insights into atmospheric chemistry and dynamics, including excited molecular oxygen.