@article{fdi:010057150,
  title = {{E}stimating canopy nitrogen concentration in sugarcane using field imaging spectroscopy},
  author = {{M}iphokasap, {P}. and {H}onda, {K}. and {V}aiphasa, {C}. and {S}ouris, {M}arc and {N}agai, {M}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he retrieval of nutrient concentration in sugarcane through hyperspectral remote sensing is widely known to be affected by canopy architecture. {T}he goal of this research was to develop an estimation model that could explain the nitrogen variations in sugarcane with combined cultivars. {R}eflectance spectra were measured over the sugarcane canopy using a field spectroradiometer. {T}he models were calibrated by a vegetation index and multiple linear regression. {T}he original reflectance was transformed into a {F}irst-{D}erivative {S}pectrum ({FDS}) and two absorption features. {T}he results indicated that the sensitive spectral wavelengths for quantifying nitrogen content existed mainly in the visible, red edge and far near-infrared regions of the electromagnetic spectrum. {N}ormalized {D}ifferential {I}ndex ({NDI}) based on {FDS}(750/700) and {R}atio {S}pectral {I}ndex ({RVI}) based on {FDS}(724/700) are best suited for characterizing the nitrogen concentration. {T}he modified estimation model, generated by the {S}tepwise {M}ultiple {L}inear {R}egression ({SMLR}) technique from {FDS} centered at 410, 426, 720, 754, and 1,216 nm, yielded the highest correlation coefficient value of 0.86 and {R}oot {M}ean {S}quare {E}rror of the {E}stimate ({RMSE}) value of 0.033% {N} (n = 90) with nitrogen concentration in sugarcane. {T}he results of this research demonstrated that the estimation model developed by {SMLR} yielded a higher correlation coefficient with nitrogen content than the model computed by narrow vegetation indices. {T}he strong correlation between measured and estimated nitrogen concentration indicated that the methods proposed in this study could be used for the reliable diagnosis of nitrogen quantity in sugarcane. {F}inally, the success of the field spectroscopy used for estimating the nutrient quality of sugarcane allowed an additional experiment using the polar orbiting hyperspectral data for the timely determination of crop nutrient status in rangelands without any requirement of prior cultivar information.},
  keywords = {hyperspectral ; imaging spectroscopy ; nitrogen concentration ; sugarcane ; canopy architecture ; first derivative spectrum ; absorption feature},
  booktitle = {},
  journal = {{R}emote {S}ensing},
  volume = {4},
  numero = {6},
  pages = {1651--1670},
  ISSN = {2072-4292},
  year = {2012},
  DOI = {10.3390/rs4061651},
  URL = {https://www.documentation.ird.fr/hor/fdi:010057150},
}