In-water lidar simulations: the ALADIN ADM-Aeolus backscattered signal at 355 nm

Area of Science:

• Ocean optics
• Remote sensing
• Lidar technology

Background:

• Spaceborne lidar instruments like ALADIN ADM-Aeolus operate in the ultraviolet (UV) spectrum.
• Understanding light propagation in water is crucial for oceanographic studies.

Purpose of the Study:

• To develop and utilize the Lidar Ocean Color (LiOC) Monte Carlo code for simulating UV lidar signals in aquatic environments.
• To assess the potential of UV lidar for ocean color remote sensing and retrieval of bio-optical properties.

Main Methods:

• Simulating UV lidar (355 nm) beam propagation in water using the LiOC Monte Carlo code.
• Accounting for sea surface interactions, water volume constituents (pure seawater, Chlorophyll-a, CDOM, absorbing species), and sea bottom reflection.
• Analyzing the normalized backscattered signal variability under diverse bio-optical conditions.
• Developing a lookup table to estimate non-Chlorophyll-a absorption.

Main Results:

• The LiOC code successfully simulates UV lidar signal propagation, considering various oceanic components.
• Variability in the normalized backscattered signal was documented across different bio-optical scenarios.
• A lookup table demonstrated the potential for estimating absorption beyond that attributed to Chlorophyll-a.
• Results highlight the value of UV bands for ocean color remote sensing.

Conclusions:

• The LiOC code is a valuable tool for simulating UV lidar interactions with aquatic systems.
• UV lidar shows promise for retrieving ocean absorption properties and advancing ocean color remote sensing.
• Future space missions, like NASA's PACE, can benefit from exploiting UV spectral regions for oceanographic research.