Lawrence A. Corp,1
Elizabeth M. Middleton,2
James E. McMurtrey,3
Petya K. Entcheva Campbell,4
and L. Maryn Butcher1
1L. A. Corp (lcorp@hydrolab.arsusda.gov) and L. M. Butcher are with Science Systems and Applications, Inc., Lanham, Maryland 20706. USA
2E. M. Middleton is with the Biospheric Sciences Branch, NASA∕Goddard Space Flight Center, Greenbelt, Maryland 20771. USA
3J. E. McMurtrey is with the Hydrology & Remote Sensing Laboratory, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, Maryland 20705. USA
4P. K. Entcheva Campbell is with the Joint Center for Earth Systems Technology, University of Maryland, Baltimore County, Baltimore, Maryland 21250. USA
Lawrence A. Corp, Elizabeth M. Middleton, James E. McMurtrey, Petya K. Entcheva Campbell, and L. Maryn Butcher, "Fluorescence sensing techniques for vegetation assessment," Appl. Opt. 45, 1023-1033 (2006)
Active fluorescence (F) sensing systems have long been suggested as a means to identify species composition and determine physiological status of plants. Passive F systems for large-scale remote assessment of vegetation will undoubtedly rely on solar-induced F (SIF), and this information could potentially be obtained from the Fraunhofer line depth (FLD) principle. However, understanding the relationships between the information and knowledge gained from active and passive systems remains to be addressed. Here we present an approach in which actively induced F spectral data are used to simulate and project the magnitude of SIF that can be expected from near-ground observations within selected solar Fraunhofer line regions. Comparisons among vegetative species and nitrogen (N) supply treatments were made with three F approaches: the passive FLD principle applied to telluric oxygen bands from field-acquired canopy reflectance spectra, simulated SIF from actively induced laboratory emission spectra of leaves at a series of solar Fraunhofer lines ranging from 422 to , and examination of two dual-F excitation algorithms developed from laboratory data. From these analyses we infer that SIF from whole-plant canopies can be simulated by use of laboratory data from active systems on individual leaves and that SIF has application for the large-scale assessment of vegetation.
J. C. McFarlane, R. D. Watson, A. F. Theisen, R. D. Jackson, W. L. Ehrler, P. J. Pinter, S. B. Idso, and R. J. Reginato Appl. Opt. 19(19) 3287-3289 (1980)
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Chlorophyll (Chl) contents are in micrograms per meter squared.
Photosynthetic units (Amax) are in micromoles of CO2 per meter squared per second.
Gain yields are reported in kilograms per hectare.
Nitrogen treatment levels in field corn are expressed in kilograms of nitrogen per hectare.
Within a treatment group, isoline, or species columnwise means with the same letter are not separable (ns) by the means comparison procedure.
Groupwise LSD0.05 values indicate the smallest separable source of variation for each variable.
Table 2
Mean EX by EM Wavelengths (nm) for EEM Maxima, across Five Plant Species
F intensities are reported in milliwatts per square meter divided by nanometers per steradian.
Fs is expressed as total photons per second from both ChlF peaks .
Nitrogen treatment levels on field corn are expressed in kilograms of nitrogen per hectare.
Within a treatment group, isoline, or species columnwise means with the same letter are not separable (ns) by the means comparison procedure.
Groupwise LSD0.05 values indicate the smallest separable source of variation for each variable.
Table 4
Simulated SIF in Fraunhofer Solar Lines as Determined from Leaf EX Spectraa
Numbers in italic denote closest proximity to actively induced EM maxima.
The solar atmospheric element or ion (I) source along with the central wavelength location and equivalent width were generated from the second revision of Rowland's Table of Solar Spectrum Wavelengths.30
Tables (4)
Table 1
Effects of Treatment on Biophysical Measures of Plant Growth and Condition
Chlorophyll (Chl) contents are in micrograms per meter squared.
Photosynthetic units (Amax) are in micromoles of CO2 per meter squared per second.
Gain yields are reported in kilograms per hectare.
Nitrogen treatment levels in field corn are expressed in kilograms of nitrogen per hectare.
Within a treatment group, isoline, or species columnwise means with the same letter are not separable (ns) by the means comparison procedure.
Groupwise LSD0.05 values indicate the smallest separable source of variation for each variable.
Table 2
Mean EX by EM Wavelengths (nm) for EEM Maxima, across Five Plant Species
F intensities are reported in milliwatts per square meter divided by nanometers per steradian.
Fs is expressed as total photons per second from both ChlF peaks .
Nitrogen treatment levels on field corn are expressed in kilograms of nitrogen per hectare.
Within a treatment group, isoline, or species columnwise means with the same letter are not separable (ns) by the means comparison procedure.
Groupwise LSD0.05 values indicate the smallest separable source of variation for each variable.
Table 4
Simulated SIF in Fraunhofer Solar Lines as Determined from Leaf EX Spectraa
Numbers in italic denote closest proximity to actively induced EM maxima.
The solar atmospheric element or ion (I) source along with the central wavelength location and equivalent width were generated from the second revision of Rowland's Table of Solar Spectrum Wavelengths.30