Related Experiment Video
Updated: Jun 7, 2026
06:48
A Multimodal Wide-Field Fourier-Transform Raman Microscope
Published on: December 30, 2025
Asymmetrical spectral curvature algorithms: oceanic-constituents sensitivities
Applied Optics
|October 22, 2010
Summary
A new ocean color algorithm using asymmetrical spectral curvature shows improved pigment retrieval sensitivity. This method is less affected by non-absorbing particulate backscatter and dissolved organic material, offering potential for validating other algorithms.
Area of Science:
- Oceanography
- Remote Sensing
- Biogeochemistry
Background:
- Accurate retrieval of oceanic pigment concentrations is crucial for understanding marine primary productivity.
- Existing algorithms, like those using Coastal Zone Color Scanner (CZCS) sensor bands, have limitations in sensitivity and susceptibility to optical constituents.
- Asymmetrical spectral curvature algorithms offer a novel approach to ocean color data analysis.
Purpose of the Study:
- To characterize the asymmetrical spectral curvature algorithm for Morel case 1 waters.
- To compare the pigment-retrieval sensitivity of different asymmetrical spectral curvature algorithms.
- To investigate the algorithm's performance concerning non-absorbing particulate backscatter (NAB) and dissolved organic material (DOM) absorption.
Main Methods:
- Application of a semianalytical radiance model of ocean color.
- Utilized post-Coastal Zone Color Scanner (CZCS) sensor bands for analysis.
- Evaluated the [L(490)/L(443)][L(490)/L(555)] asymmetrical spectral curvature algorithm.
Main Results:
- The [L(490)/L(443)][L(490)/L(555)] algorithm demonstrates higher pigment-retrieval sensitivity compared to the [L(490)/L(443)][L(490)/L(510)] algorithm.
- This algorithm exhibits intermediate sensitivity to pigment retrieval compared to CZCS-type radiance-ratio algorithms ([L(443)/L(555)] and [L(510)/L(555)]).
- The algorithm shows reduced sensitivity to NAB and remarkable insensitivity to DOM absorption, with a NAB invariance point at a specific curvature value.
Conclusions:
- The [L(490)/L(443)][L(490)/L(555)] algorithm offers improved performance for pigment retrieval in ocean color analysis.
- The identified NAB invariance point, where the algorithm is insensitive to both DOM and NAB, presents a unique characteristic.
- This invariance point warrants further investigation for validating other pigment algorithms, model inversions, and computing inherent optical properties.
More Related Videos
07:11ARL Spectral Fitting as an Application to Augment Spectral Data via Franck-Condon Lineshape Analysis and Color Analysis
Published on: August 19, 2021
09:32Resolving Water, Proteins, and Lipids from In Vivo Confocal Raman Spectra of Stratum Corneum through a Chemometric Approach
Published on: September 26, 2019
Related Concept Videos
01:08IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations
Identical bonds within a polyatomic group can stretch symmetrically (in-phase) or asymmetrically (out-of-phase). Similar to hydrogen bonding, these vibrations also influence the shape of the IR peak. Generally, asymmetric stretching frequencies are higher than symmetric stretching frequencies. For example, primary amines exhibit two distinct IR peaks between 3300–3500 cm−1 corresponding to the symmetric and asymmetric N-H stretching, while secondary amines exhibit a single stretching vibration...
01:26Influence of Earth's Curvature and Atmospheric Refraction on Leveling
During leveling, the Earth's curvature and atmospheric refraction introduce deviations in the line of sight from a true horizontal reference. When the line of sight is leveled, it remains perpendicular to the plumb line only at a single point. Beyond this, it deviates due to the Earth’s curvature, represented by the correction C. For a sight distance D, the deviation can be derived using the relationship:This relationship shows that the deviation increases quadratically with distance. Over a...
01:26Spectroscopy of Carboxylic Acid Derivatives
Infrared spectroscopy is primarily used to determine the types of bonds and functional groups. In carboxylic acid derivatives, a typical carbonyl bond absorption is observed around 1650–1850 cm−1. For esters, the absorption is recorded at around 1740 cm−1, while acid halides show the absorption at about 1800 cm−1. Another acid derivative, the acid anhydrides, exhibit two carbonyl absorption around 1760 cm−1 and 1820 cm−1, arising from the symmetrical and unsymmetrical carbonyl vibration.
In the...
In the...
01:30UV–Vis Spectrum
When light passes through a substance, a portion of the light is absorbed while the remaining light is reflected or transmitted. If the molecule absorbs light between the wavelengths of 180–400 nm range, the UV spectrum is obtained, and if it absorbs light in the 400–780 nm wavelength range, the visible spectrum is obtained.
The UV–Vis spectrum of a molecule is the plot of its absorbance versus wavelength. The plot is drawn by taking molar absorptivity (ε) or log ε on the y-axis (ordinate)...
The UV–Vis spectrum of a molecule is the plot of its absorbance versus wavelength. The plot is drawn by taking molar absorptivity (ε) or log ε on the y-axis (ordinate)...
01:02Ultraviolet and Visible (UV–Vis) Spectroscopy: Overview
Ultraviolet–visible (UV–visible or UV–Vis) spectroscopy is an analytical technique that investigates the interaction between matter and UV–Vis light within the electromagnetic spectrum. This method is widely used for its versatility, simplicity, and relatively quick data acquisition, making it valuable for both qualitative and quantitative analysis. When UV–Vis radiation passes through a material, molecules absorb light depending on the energy required for electronic transitions. As a result...
01:29UV–Vis Spectroscopy: Woodward–Fieser Rules
UV–Visible absorption spectra of conjugated dienes arise from the lowest energy π → π* transitions. The light-absorbing part of the molecule is called the chromophore, and the substituents directly attached to the chromophore are called auxochromes. A strong correlation exists between the absorption maxima, λmax, and the structure of a conjugated π system. The Woodward–Fieser rules predict the value of λmax for a given structure by adding the contributions...