The Airborne Visible/Infrared Imaging Spectrometer-4 (AVIRIS-4) represents the next generation in the series of airborne imaging spectrometers built by NASA JPL. Commissioned by the Swiss ARES research consortium, AVIRIS-4 is geared towards delivering cutting-edge imaging spectroscopy data for scientific and practical applications as a replacement for its predecessor APEX. AVIRIS-4 is based on a Dyson-type imaging spectrometer design, also employed by NASA-operated AVIRIS-3 and 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 m 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 performance and features a spectral range of 375 to 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 is developed by UZH, EPFL, and ZHAW. This paper outlines the design and calibration strategies implemented in AVIRIS-4's development and highlights its performance during its first year of operation in 2024.