A balloon-borne imaging Fourier transform spectrometer for atmospheric trace gas profiling

Area of Science:

• Atmospheric Science
• Remote Sensing
• Climate Change Research

Background:

• The upper troposphere and lower stratosphere (UTLS) is vital for climate but undersampled by satellites.
• Imaging Fourier Transform Spectrometer (FTS) technology offers potential for precise UTLS trace gas measurements.

Purpose of the Study:

• To detail the design and performance of the balloon-borne Limb Imaging Fourier Transform Spectrometer Experiment (LIFE) instrument.
• To serve as a prototype for a future low Earth orbit satellite instrument for UTLS atmospheric monitoring.

Main Methods:

• Design and construction of the LIFE instrument using off-the-shelf components, emphasizing reduced complexity and cooling requirements.
• Characterization through thermal and vacuum tests.
• Validation via a demonstration balloon flight during the 2019 Strato-Science campaign.

Main Results:

• The LIFE instrument was validated through a successful demonstration balloon flight.
• A calibration issue concerning blackbody emissivity was identified and mitigated using an emissivity ratio.
• The instrument demonstrated capability to meet primary performance requirements for trace gas retrievals.

Conclusions:

• The LIFE instrument represents a feasible approach for obtaining high-precision atmospheric trace gas composition data in the UTLS.
• Despite a minor calibration challenge, the instrument's performance meets essential requirements for monitoring key greenhouse gases.