Press Release:
Ground truthing vegetation using a field spectroradiometer and portable RT sphere to measure leaf stress.
Lawrence, MA – October 12, 2016 – Hyperspectral imaging can provide important information on vegetation health whether measuring crops, fields, or forest canopies. Ground truthing provides the ability to check and fine-tune the results of hyperspectral activities. Spectral Evolution designs and manufactures field portable spectroradiometers, spectrometers and accessories to make field research easier, more reliable, and more active. As part of our ongoing instrument development, we can provide researchers with the PSR+ NIR field spectroradiometers and a six inch, portable reflectance/transmittance (RT) sphere to measure leaf characteristics, red edge shift and plant stress.
Typically, an increase in reflectance and transmittance and a decrease in absorption in the 695-725nm range can be a very good indication of a leaf’s response to plant stress. The changes in these measurements noted in this wavelength range can be a sign that the plant is losing chlorophyll with a reduction that can be seen in the absorption features related to chlorophyll in the leaf.
Reflectance, transmittance, and absorption for healthy leaves as well as stressed leaves tend to show only slight differences in the 400-500nm range as opposed to those differences that are more prominent in the 695-725nm range.
Signs of stress can be due to almost any cause that will result in less absorption of chlorophyll: water stress, pests, over use of fertilizer, flooding, herbicide misuse, flooding, elevated ozone and CO2, etc.
Spectral Evolution’s reflectance/transmittance (RT) sphere can be used to measure reflectance and transmittance for a wide variety of sample types including vegetation samples such as leaves or needles. The RT sphere can be used for specular included or excluded reflectance measurement,
measurement of forward and back scattering, and transmittance measurement of scattering transparent or turbid samples. At 6 inches in height and weighing less than 5 pounds, the RT sphere is portable and well-suited for field use with the PSR+™ spectroradiometer.
An RT sphere allows you to collect all diffuse light reflected from a leaf since the inside of the sphere is a perfect reflecting diffuser—total hemispherical reflectance can be measured. With the high resolution spectra obtained from a Spectral Evolution spectroradiometer, the RT sphere can deliver detailed information about vegetation spectral features, such as comparisons of chlorophyll concentrations of leaves with the red-edge
characteristics.
The PSR+ is a high resolution/high sensitivity field spectroradiometer covering the full UV/VIS/NIR range from 350-2500nm. It also provides for easy field use with auto-shutter, auto-exposure, and auto-dark exposure for one-touch operation. With no moving optics and its optimized optical path, it is designed for field reliability under a broad range of field conditions. Three photodiode arrays include a 512 element silicon detector and two 256 element TE-cooled extended wavelength array InGaAs detectors covering the 350-2500nm spectral range, all carefully selected and matched for optimum performance.
The PSR+ can be combined with a wide range of accessories including a range of FOV options such as direct attaching 4°, 8°, or 14° lenses, 25° fiber optic, diffuser, or integrating sphere. Fiber mount options include 1, 2, 3, 4, 5, 8, and 10° lenses. It can be used with a sample contact probe, leaf clip, or benchtop probe with sample compactor and can store 1,000 spectra on the instrument without a computer. Communications
interfaces include USB and Class 1 Bluetooth. The DARWin™ Data Acquisition software makes operation easy including access to 19 vegetation indices. All data is saved as ASCII files for use with other programs, such as ENVI and chemometrics software. The PSR+ 3500 can be configured with EZ-ID™ sample identification software with the Custom Library Builder module for creating your own specific spectral library for real time sample identification.
Below are some spectra collected with the RT sphere and PSR+.
Hydrangea reflectance
Hydrangea transmittance
Lily reflectance
Lily transmittance
For more information on the RT sphere and the PSR+, visit:
http://www.spectralevolution.com/applications_RT_Sphere_leaf_stress.html
About SPECTRAL EVOLUTION
Established in 2004, SPECTRAL EVOLUTION is a leading manufacturer of laboratory and handheld portable spectrometers, spectroradiometers and spectrophotometers. SPECTRAL EVOLUTION spectrometers are used worldwide for many mission-critical lab and field applications in mining, remote
sensing, vegetative studies, ground truthing, environmental and climate studies, developing satellite calibrations, and more, due to their reliable, robust, rugged design and user-friendly one-touch features.
SPECTRAL EVOLUTION maintains a facility in Lawrence, Massachusetts which houses design, prototyping, manufacturing and service facilities for the instruments that it markets and sells worldwide, either through direct sales, OEM sales or through distributor agents.
Press Contact
Nicolas Venjean
Marketing & Sales
978-687-1833
Nicolas.Venjean@spectralevolution.com
SPECTRAL EVOLUTION
26 Parkridge Road, Suite 104
Haverhill, MA 01835 USA
www.spectralevolution.com