Correction of illumination effects on seasonal divergent NIRv photosynthetic phenology

Chen, Rui; Yin, Gaofei; Liu, Guoxiang; Yang, Yajie; Wang, Changjing; Xie, Qiaoyun; Zhao, Wei; Verger, Aleixandre

doi:10.1016/j.agrformet.2023.109542

Cited by 6 publications

(2 citation statements)

References 66 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Two vegetation indices, NIRv and enhanced vegetation index (EVI), were derived from the surface reflectance data of Sentinel-2 L2A [33,34]. Due to the study sites being located in mountainous areas, the impact of terrain on illumination conditions was often substantial, and thus, topographic effects were corrected to prevent distortion of the vegetation indices [16]. We applied the path length correction (PLC) method, referring to [35].…”

Section: Sentinel-2 Vegetation Indicesmentioning

confidence: 99%

See 1 more Smart Citation

Insights into Canopy Escape Ratio from Canopy Structures: Correlations Uncovered through Sentinel-2 and Field Observation

Lee,

Im,

Lim

et al. 2024

Forests

View full text Add to dashboard Cite

This study explores the quantitative relationship between canopy structure and the canopy escape ratio (fesc), measured as the ratio of near-infrared reflectance of vegetation (NIRv) to the fraction of absorbed photosynthetically active radiation (fAPAR). We analyzed the correlation between fesc and key indicators of canopy structure—specifically, leaf area index (LAI) and clumping index (CI)—utilizing both Sentinel-2 satellite data and in situ observations. Our analysis revealed a moderate correlation between fesc and LAI, evidenced by an R2 value of 0.37 for satellite-derived LAI, which contrasts with the lower correlation (R2 of 0.15) observed with field-measured LAI. Conversely, the relationship between fesc and CI proved to be significantly weaker (R2 < 0.1), indicating minimal interaction between foliage distribution and light escape at the canopy level. This disparity in correlation strength was further evidenced in time series analysis, which showed little phenological variation in fesc compared to LAI. Our findings elucidate the complexities of estimating fesc based on the NIRv to fAPAR ratio and underscore the need for advanced methodologies in future research to enhance the accuracy of canopy escape models.

show abstract

Section: Sentinel-2 Vegetation Indicesmentioning

confidence: 99%

“…In addition, [13] also demonstrated little saturation between NIRv and canopy photosynthesis, even at low LAI values. In this way, recent studies have used NIRv as a structural indicator in various areas, such as plant phenology [14][15][16][17], crop yield estimation [18], and drought stress assessment [19,20].…”

Section: Introductionmentioning

confidence: 99%