Estimation of inherent optical properties from irradiance measurements: Monte Carlo simulations

1990 ◽  
Author(s):  
Howard R. Gordon
2011 ◽  
Vol 2 (3) ◽  
pp. 552 ◽  
Author(s):  
Mathieu Dehaes ◽  
P. Ellen Grant ◽  
Danielle D. Sliva ◽  
Nadège Roche-Labarbe ◽  
Rudolph Pienaar ◽  
...  

Author(s):  
Jonathan T. Elliott ◽  
Mamadou Diop ◽  
Ting-Yim Lee ◽  
Keith St. Lawrence ◽  
Kenneth M. Tichauer

2021 ◽  
Author(s):  
Christophe Perron ◽  
Christian Katlein ◽  
Simon Lambert-Girard ◽  
Edouard Leymarie ◽  
Louis-Philippe Guinard ◽  
...  

Abstract. Detailed characterization of the spatially and temporally varying inherent optical properties (IOPs) of sea ice is necessary to better predict energy and mass balances, as well as ice-associated primary production. Here we present the development of an active optical probe to measure IOPs of a small volume of sea ice (dm3) in situ and non-destructively. The probe is derived from the diffuse reflectance method used to measure the IOPs of human tissues. The instrument emits light into the ice by the use of optical fibre. Backscattered light is measured at multiple distances away from the source using several receiving fibres. Comparison to a Monte Carlo simulated lookup table allows to retrieve the absorption coefficient, the reduced scattering coefficient and a phase function similarity parameter γ, introduced by Bevilacqua and Depeursinge (1999), depending on the two first moments of the Legendre polynomials, allowing to analyze the backscattered light not satisfying the diffusion regime. Monte Carlo simulations showed that the depth cumulating 95% of the signal is between 40±2 mm and 270±20 mm depending on the source-detector distance and on the ice scattering properties. The magnitude of the instrument validation error on the reduced scattering coefficient ranged from 0.07% for the most scattering medium to 35% for the less scattering medium over the two orders of magnitude we validated. Vertical profiles of the reduced scattering coefficient were obtained with decimeter resolution on first-year Arctic interior sea ice on Baffin Island in early spring 2019. We measured values of up to 7.1 m−1 for the uppermost layer of interior ice and down to 0.15±0.05 m−1 for the bottommost layer. These values are in the range of polar interior sea ice measurements published by other authors. The inversion of the reduced scattering coefficient at this scale was strongly dependent of γ, highlighting the need to define the higher moments of the phase function. This novel developed probe provides a fast and reliable means for measurement of scattering into sea ice.


2020 ◽  
Vol 12 (17) ◽  
pp. 2820
Author(s):  
Qun Liu ◽  
Xiaoyu Cui ◽  
Cédric Jamet ◽  
Xiaolei Zhu ◽  
Zhihua Mao ◽  
...  

Spaceborne lidar (light detection and ranging) is a very promising tool for the optical properties of global atmosphere and ocean detection. Although some studies have shown spaceborne lidar’s potential in ocean application, there is no spaceborne lidar specifically designed for ocean studies at present. In order to investigate the detection mechanism of the spaceborne lidar and analyze its detection performance, a spaceborne oceanic lidar simulator is established based on the semianalytic Monte Carlo (MC) method. The basic principle, the main framework, and the preliminary results of the simulator are presented. The whole process of the laser emitting, transmitting, and receiving is executed by the simulator with specific atmosphere–ocean optical properties and lidar system parameters. It is the first spaceborne oceanic lidar simulator for both atmosphere and ocean. The abilities of this simulator to characterize the effect of multiple scattering on the lidar signals of different aerosols, clouds, and seawaters with different scattering phase functions are presented. Some of the results of this simulator are verified by the lidar equation. It is confirmed that the simulator is beneficial to study the principle of spaceborne oceanic lidar and it can help develop a high-precision retrieval algorithm for the inherent optical properties (IOPs) of seawater.


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