The AVIRIS-4 Airborne Imaging Spectrometer

The Airborne Visible/Infrared Imaging Spectrometer-4 (AVIRIS-4) represents the next generation in the series of airborne imaging spectrometers built by National Aeronautics and Space Administration (NASA) Jet Propulsion Laboratory (JPL). Commissioned by the Swiss Airborne Research Facility for the Earth System (ARES) research consortium, AVIRIS-4 is geared toward delivering cutting-edge imaging spectroscopy data for scientific and practical applications as a replacement for its predecessor Airborne Prism EXperiment (APEX). AVIRIS-4 is based on a Dyson-type imaging spectrometer design, also employed by NASA-operated AVIRIS-3 and Earth Surface Mineral Dust Source Investigation (EMIT), and integrates a scaled two-mirror telescope housed in a compact vacuum vessel. This enables airborne measurements in unpressurized aircraft at altitudes ranging from 500 to 7620 m, achieving image resolutions between 0.3 and 4.5 m with a field of view of 40.2° in 1241 spatial pixels. AVIRIS-4 surpasses previous state-of-the-art sensor heads in signal-to-noise ratio (SNR) performance and features a spectral range of 375–2504 nm and 7.4-nm spectral sampling. The operation, data capture, and mission control hardware as well as the calibration and data processing software are developed by UZH, EPFL, and ZHAW. This letter outlines the design and calibration strategies implemented in AVIRIS-4’s development and highlights its performance during its first year of operation in 2024.