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Simulating Imaging of Large Scale Radio Arrays on the Lunar Surface
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Adjacency radiance around a small island: implications for system vicarious calibrations
Applied Optics
|May 14, 2020
Summary
Adjacency effects around Lampedusa Island impact satellite ocean color data. These effects, particularly negative ones in the sunbeam direction, complicate vicarious calibration (SVC) for sensors like the Ocean Land Color Instrument (OLCI).
Area of Science:
- Oceanography
- Remote Sensing
- Radiometry
Background:
- Vicarious calibration (SVC) is crucial for satellite ocean color sensors.
- Islands can introduce adjacency effects (AE) that influence radiance measurements.
- Understanding AE is vital for accurate ocean color data retrieval.
Purpose of the Study:
- To analyze the adjacency radiance field around Lampedusa Island.
- To assess the implications of these AE on a hypothetical SVC infrastructure.
- To evaluate AE impact on Sentinel-3's Ocean Land Color Instrument (OLCI).
Main Methods:
- Theoretical analysis of adjacency radiance fields.
- Simulations in visible and near-infrared spectral regions.
- Modeling for the Ocean Land Color Instrument (OLCI) on Sentinel-3.
Main Results:
- AE patterns vary around the island, with negative AE in the sunbeam direction due to missing glint.
- Negative AE decrease with wavelength and depend on sea state and illumination.
- Positive AE in other regions do not exceed OLCI radiometric sensitivity beyond 14 km.
Conclusions:
- Adjacency effects introduce significant uncertainties in satellite radiance near Lampedusa Island.
- These uncertainties hinder the fulfillment of SVC requirements at distances closer than 14 km.
- Accurate AE characterization is essential for reliable ocean color measurements and calibration.
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