A Hybrid Interlayer Reflective Boundary Approximation for Hyperspectral Cloud Radiance Simulation Under Optically Thick Liquid Cloud Conditions.
Saved in:
| Title: | A Hybrid Interlayer Reflective Boundary Approximation for Hyperspectral Cloud Radiance Simulation Under Optically Thick Liquid Cloud Conditions. |
|---|---|
| Authors: | He, Xiaoyu1 (AUTHOR), Jia, Shilong1 (AUTHOR), Liu, Tianjin1 (AUTHOR) tianjinliu@buaa.edu.cn |
| Source: | Remote Sensing. Jun2026, Vol. 18 Issue 11, p1742. 25p. |
| Subjects: | Radiative transfer, Satellite-based remote sensing |
| Abstract: | Highlights: What are the main findings? Conventional layered radiative transfer models underestimate hyperspectral cloud radiance under optically thick conditions; this issue is demonstrated here over the 0.8–2.5 μm range within the broader visible-to-shortwave infrared (VIS–SWIR) domain. The proposed extinction-dependent interlayer reflective augmentation improves spectral representation of thick-cloud radiance in the evaluated Gaofen-5A (GF-5A) scenes by distributing reflective enhancement over discretized sublayer interfaces rather than imposing a single bulk cloud-boundary term. What are the implications of the main findings? The method provides a fast and physically consistent forward model for hyperspectral cloud radiance simulation, bridging the gap between baseline layered radiative transfer (RT) and high-cost reference solvers. It provides an efficient forward approximation for hyperspectral radiance simulation of optically thick cloud scenes and shows practical potential for hyperspectral image simulation workflows. Accurate simulation of hyperspectral cloud radiance remains challenging under optically thick cloud conditions, where conventional layered radiative transfer (RT) models tend to underestimate cloud-induced backscattering and return radiance in the visible to shortwave infrared (VIS–SWIR) range. In this study, we propose an extinction-dependent interlayer reflective augmentation within a Curtis–Godson (CG)-based layered RT framework. While the cloud-top and cloud-bottom heights are still used to define the cloudy layer in the radiative transfer simulation, the proposed method does not impose a single bulk reflective boundary at the cloud scale. Instead, it adds an extinction-dependent reflective coupling term at discretized sublayer interfaces to compensate for the underrepresented backward radiative contribution in standard layered solvers. The proposed approach is designed for optically thick, plane-parallel cloud conditions and aims to improve forward radiance simulation rather than detailed microphysical retrieval. The formulation is constructed so that the reflective augmentation vanishes as the local extinction decreases, although the present experiments focus on optically thick liquid-cloud cases. The numerical evaluation is conducted over the 0.8–2.5 μm range, corresponding to the valid unsaturated Gaofen-5A (GF-5A) bands used for comparison. Validation using GF-5A hyperspectral observations indicates that the proposed method improves the spectral fidelity of simulated thick-cloud radiance under the adopted representative cloud-parameter setting and scene-level anchoring strategy. Relative to the baseline compact layered RT formulation, the proposed method provides a favorable balance between computational efficiency and spectral accuracy, making it suitable as a fast forward module for hyperspectral cloud radiance simulation of optically thick liquid-cloud scenes. [ABSTRACT FROM AUTHOR] |
| Copyright of Remote Sensing is the property of MDPI and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
|
Full text is not displayed to guests.
Login for full access.
|
|
| Abstract: | Highlights: What are the main findings? Conventional layered radiative transfer models underestimate hyperspectral cloud radiance under optically thick conditions; this issue is demonstrated here over the 0.8–2.5 μm range within the broader visible-to-shortwave infrared (VIS–SWIR) domain. The proposed extinction-dependent interlayer reflective augmentation improves spectral representation of thick-cloud radiance in the evaluated Gaofen-5A (GF-5A) scenes by distributing reflective enhancement over discretized sublayer interfaces rather than imposing a single bulk cloud-boundary term. What are the implications of the main findings? The method provides a fast and physically consistent forward model for hyperspectral cloud radiance simulation, bridging the gap between baseline layered radiative transfer (RT) and high-cost reference solvers. It provides an efficient forward approximation for hyperspectral radiance simulation of optically thick cloud scenes and shows practical potential for hyperspectral image simulation workflows. Accurate simulation of hyperspectral cloud radiance remains challenging under optically thick cloud conditions, where conventional layered radiative transfer (RT) models tend to underestimate cloud-induced backscattering and return radiance in the visible to shortwave infrared (VIS–SWIR) range. In this study, we propose an extinction-dependent interlayer reflective augmentation within a Curtis–Godson (CG)-based layered RT framework. While the cloud-top and cloud-bottom heights are still used to define the cloudy layer in the radiative transfer simulation, the proposed method does not impose a single bulk reflective boundary at the cloud scale. Instead, it adds an extinction-dependent reflective coupling term at discretized sublayer interfaces to compensate for the underrepresented backward radiative contribution in standard layered solvers. The proposed approach is designed for optically thick, plane-parallel cloud conditions and aims to improve forward radiance simulation rather than detailed microphysical retrieval. The formulation is constructed so that the reflective augmentation vanishes as the local extinction decreases, although the present experiments focus on optically thick liquid-cloud cases. The numerical evaluation is conducted over the 0.8–2.5 μm range, corresponding to the valid unsaturated Gaofen-5A (GF-5A) bands used for comparison. Validation using GF-5A hyperspectral observations indicates that the proposed method improves the spectral fidelity of simulated thick-cloud radiance under the adopted representative cloud-parameter setting and scene-level anchoring strategy. Relative to the baseline compact layered RT formulation, the proposed method provides a favorable balance between computational efficiency and spectral accuracy, making it suitable as a fast forward module for hyperspectral cloud radiance simulation of optically thick liquid-cloud scenes. [ABSTRACT FROM AUTHOR] |
|---|---|
| ISSN: | 20724292 |
| DOI: | 10.3390/rs18111742 |
