Photon Systems Instruments PlantPen NDVI 310, Руководство пользователя и инструкция пользователя

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© PSI (Photon Systems Instruments), spol. s r. o.
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3 GENERAL INFORMATION
The PlantPen model PRI 210 measures Photochemical Reflectance Index (PRI) in two narrow wavelength bands centered
close to 531 nm and 570 nm. The photochemical reflectance index (PRI = (R531 – R570)/(R531+R570)) correlates with the
epoxidation state of xanthophyll cycle pigments and photosystem efficiency in many studies under diverse conditions, such
as different
1
. PRI is sensitive to changes in carotenoid pigments that are indicative of photosynthetic light use efficiency,
the rate of carbon dioxide uptake, or as a reliable water-stress index. As such, it is used in studies of vegetation productivity
and stress.
The PlantPen model NDVI 310 measures Normalized Difference Vegetation Index , which is an important indicator of
chlorophyll content in plants. The pigment in plant leaves, chlorophyll, strongly absorbs visible light (from 0.4 to 0.7 µm)
for use in photosynthesis. The cell structure of the leaves, on the other hand, strongly reflects near-infrared light (from 0.7
to 1.1 µm). The differences in plant reflectance in the visible and near -infrared wavelengths is used to calculate NDVI index
as follows: NDVI=((NIR-VIS)/((NIR+VIS)), where VIS and NIR stand for the spectral reflectance measurements acquired in
the visible (red) and near-infrared regions, respectively. NDVI is directly related to the photosynthetic capacity and hence
energy absorption of plant canopies
2
. The NDVI 310 device compares reflected light at two distinct wavelengths, 635 and
760 nm.
PlantPen can be operated as a stand-alone instrument and thus is ideal for field studies. Measured data are sequentially
stored in the internal PlantPen memory. Data transfer is via USB or Bluetooth communication. Comprehensive FluorPen
1.1 software provides data transfer routines and many additional features for data presentation in tables and graphs.
1
John Gamon, Josep Penuelas, and Christopher Field (1992). A narrow-waveband spectral index that tracks diurnal changes in
photosynthetic efficiency. Remote Sensing of environment, 41, 35-44.
2
Sellers, P. J. (1985) 'Canopy reflectance, photosynthesis, and transpiration', International Journal of Remote Sensing, 6, 1335-1372.