APEX - the Hyperspectral ESA Airborne Prism Experiment

Area of Science:

• Earth Observation
• Remote Sensing
• Spectroscopy

Background:

• The ESA-APEX (Airborne Prism Experiment) is a hyperspectral mission simulator designed for high-quality remote sensing data acquisition.
• Effective calibration and processing are crucial for deriving accurate scientific data products from airborne sensors.

Purpose of the Study:

• To describe the specifications and capabilities of the APEX hyperspectral sensor.
• To present the calibration strategies, data processing, and applications of the APEX mission.
• To highlight APEX's role in advancing Earth observation research.

Main Methods:

• Automatic calibration using Control Test Master (CTM) and In-Flight Calibration (IFC) facilities.
• Quality flagging (QF) and dedicated processing in a Processing and Archiving Facility (PAF).
• Vicarious calibration experiments and the use of the SPECCHIO spectral database.

Main Results:

• APEX offers state-of-the-art optical performance and dedicated software utilities.
• Development efforts focus on providing scientific data products up to Level 2/3 for various applications.
• Discussion of Bidirectional Reflectance Distribution Function (BRDF) issues and their mitigation.

Conclusions:

• APEX is a versatile hyperspectral sensor meeting the needs of multiple research communities.
• The mission contributes to a better understanding of Earth's complex mechanisms through advanced remote sensing.
• APEX enables scientific data product generation for applications in limnology, vegetation, aerosols, and mapping.