Simulating Earth’s Infrared Radiation from the Moon
MERIDIAN (Moon EaRth leto vIsibility and raDIative trANsfer) is a web-based simulation tool developed at CNR-INO (Florence) for the scientific community of the EMM research infrastructure. It models the radiative transfer from the Earth disk toward the LETO observation site on the lunar surface, integrating orbital visibility analysis with state-of-the-art atmospheric databases.
What MERIDIAN Does
Given a position on the Moon and a moment in time, MERIDIAN answers two questions simultaneously: how much of the Earth disk is visible, and what is the infrared spectrum arriving from that disk?
The tool combines precise orbital mechanics with a fast radiative transfer model into a single integrated workflow. It covers the spectral range of 100–1600 cm⁻¹ (6–100 μm) — the same operational range as LETO — and computes results across the full visible Earth disk, accounting for surface type, atmospheric conditions, and cloud cover.
Designed for the EMM Research Community
MERIDIAN was developed to support the scientific operations of LETO (Lunar Earth Temperature Observatory), an Earth observation instrument designed to continuously monitor the outgoing longwave radiation of the full Earth disk from the lunar surface.
Researchers can use MERIDIAN to plan LETO observations, evaluate candidate lunar landing sites, assess seasonal and temporal variability in Earth’s infrared emission, and build reference radiance databases for the community. Sessions can be saved and reloaded for long-running or multi-step analyses.