New earth system model for optical performance evaluation of space instruments.

Area of Science:

• Earth System Science
• Optical Engineering
• Space Instrument Design

Background:

• Evaluating space instrument optical performance is critical for mission success.
• Existing Earth system models may lack the detailed sub-models required for precise optical simulations.
• Accurate modeling is essential for predicting instrument behavior and validating design choices.

Purpose of the Study:

• To introduce a novel global Earth system model for evaluating space instrument optical performance.
• To demonstrate the model's capability in generating simultaneous imaging and spectroscopic results.
• To validate the model's accuracy by comparing simulated data with real-world observational data.

Main Methods:

• Development of a comprehensive global Earth system model with resolved spatial, spectral, and temporal sub-models (sun, atmosphere, land, ocean).
• Design of a hypothetical Cassegrain telescope imaging instrument.
• Simulation of optical performance and comparison with EPOXI mission HRI-VIS observational data.

Main Results:

• The Earth system model successfully simulated imaging and spectroscopic data.
• Defocus mapping and edge spread function (ESF) analysis revealed a primary-secondary mirror distance increase of 55.498 μm.
• Focal plane shift was determined to be 5.813 mm shorter than the defocused plane, confirmed by point spread function (PSF) measurements.

Conclusions:

• The integrated Earth system and instrument model is a powerful tool for space instrument development.
• The model enables accurate simulation and verification of optical performance.
• This approach significantly aids in the design and validation phases of space instrument missions.