Calibration of MAJIS (Moons and Jupiter Imaging Spectrometer). IV. Radiometric calibration (invited)

Area of Science:

• Planetary Science
• Space Instrumentation
• Spectroscopy

Background:

• The Moons and Jupiter Imaging Spectrometer (MAJIS) is crucial for the JUICE mission, providing spectral data from 0.5 to 5.54 μm.
• MAJIS utilizes two channels: visible-near infrared (VISNIR) and infrared (IR).

Purpose of the Study:

• To present the results of the comprehensive on-ground radiometric calibration of the MAJIS instrument.
• To characterize MAJIS detectors (H1RG) for precision and accuracy, validating readout procedures.
• To determine the instrument transfer function for both VISNIR and IR channels.

Main Methods:

• Extensive detector characterization of VISNIR and IR detectors before integration.
• Determination of linearity and operability as a function of integration time and temperature.
• Radiometric calibration of the integrated MAJIS instrument to establish DN output per unit radiance across the field of view and spectral range.

Main Results:

• Detector characterization validated readout procedures and provided linearity/operability data.
• Instrument transfer functions were determined for each MAJIS data element.
• A specific procedure was developed for VISNIR channel radiometric calibration due to stray light.
• Post-launch observations confirmed minor changes in both VISNIR and IR channels.

Conclusions:

• The on-ground calibration campaign provided essential data for MAJIS radiometric performance.
• Updated instrument transfer functions based on pre- and post-launch observations ensure accurate in-flight data.
• MAJIS is calibrated and ready for its scientific objectives during the JUICE mission.