Theoretical algorithm and application of a double-integrating sphere system for measuring leaf transmittance and reflectance spectra.

Applied optics

PubMedID: 28157912

Mõttus M, Hovi A, Rautiainen M. Theoretical algorithm and application of a double-integrating sphere system for measuring leaf transmittance and reflectance spectra. Appl Opt. 2017;56(3):563-571.
We present the theoretical background and analytical equations for calculating spectral reflectance and transmittance factors for plant leaves from data collected by a field spectroradiometer attached to a double-integrating sphere. The sphere constants required for the calculations are derived from measurements of an empty sample port and a diffuse reflectance panel. The new method is applied in measuring the spectra of leaves belonging to 13 tree species. The greatest advantages of a double-sphere system compared with the conventional single-sphere substitution method is the speed of measurements, ease of operation, and increased portability and field-ruggedness.