Radiant energy – Invisible radiant energy responsive electric signalling – Infrared responsive
Patent
1998-01-06
2000-02-01
Evans, F. L.
Radiant energy
Invisible radiant energy responsive electric signalling
Infrared responsive
356419, G01N 2135
Patent
active
060205873
ABSTRACT:
A plant chlorophyll content meter is described which collects light reflected from a target plant and separates the collected light into two different wavelength bands. These wavelength bands, or channels, are described as having center wavelengths of 700 nm and 840 nm. The light collected in these two channels are processed using photo detectors and amplifiers. An analog to digital converter is described which provides a digital representation of the level of light collected by the lens and falling within the two channels. A controller provided in the meter device compares the level of light reflected from a target plant with a level of light detected from a light source, such as light reflected by a target having 100% reflectance, or transmitted through a diffusion receptor. The percent of reflection in the two separate wavelength bands from a target plant are compared to provide a ratio which indicates a relative level of plant physiological stress. A method of compensating for electronic drift is described where a sample is taken when a collection lens is covered to prevent light from entering the device. This compensation method allows for a more accurate reading by reducing error contributions due to electronic drift from environmental conditions at the location where a hand-held unit is used.
REFERENCES:
patent: 4204950 (1980-05-01), Burford et al.
patent: 4225242 (1980-09-01), Lane
patent: 4295042 (1981-10-01), Wantanabe et al.
patent: 4650336 (1987-03-01), Moll
patent: 4804850 (1989-02-01), Norrish et al.
patent: 4986665 (1991-01-01), Yamanishi et al.
patent: 5014225 (1991-05-01), Vidaver et al.
patent: 5353053 (1994-10-01), Nishioka et al.
patent: 5389781 (1995-02-01), Beck et al.
patent: 5412219 (1995-05-01), Chapplle et al.
patent: 5467271 (1995-11-01), Abel et al.
patent: 5486915 (1996-01-01), Jeffers et al.
patent: 5576550 (1996-11-01), Koppikar
patent: 5606821 (1997-03-01), Sajadi et al.
Carter, G., "Ratios of Leaf Reflections in Narrow Wavebands as Indicators of Plant Stress", Int. J. Remote Sensing, vol. 15, No. 3, 679-703, (1994).
Carter, G., et al., "Early Detection of Plant Stress by Digital Imaging Within Narrow Stress-Sensitive Wavebands", Remote Sens. Environ 50, 295-302, (1994).
Carter, G., et al., "Leaf Optical Properties in Liriodendron tulipifera and Pinus strobus as Influenced by Increased Atmospheric Ozone and Carbon Dioxide", Can. J. For. Res. 25, 407-412, (1995).
Carter, G., et al., "Narrow-Band Reflectance Imagery Compared with Thermal Imagery for Early Detection of Plant Stress", L. Plant Physiol. vol. 148, 515-522, (1996).
Carter, G., et al., "Spectral Reflectance Characteristics and Digital Imagery of a Pine Needle Blight in the Southeastern United States", Can. J. For. Res. 26, 402-407, (1996).
Carter, G.A., "Responses of Leaf Spectral Reflectance to Plant Stress", American Journal of Botany, 239-243, (Mar. 1993).
Cibula, W.G., et al., "Identification of Far-Red Reflectance Response to Ectomycorrhizae in Slash Pine", Int. J. Remote Sensing, vol. 13, No. 5, 925-932, (1992).
Gitelson et al, Novel Algorithms for Remote Sensing of Chlorophyll Content in Higher Plant Leaves, a paper appearing in Geoscience and Remote Sensing Symposium, 1996, IGARSS '96, `Remote Sensing for a Sustainable Future.` International on pp. 2355-2357 (abstract only), 1996.
Carter Gregory A.
Spiering Bruce A.
Borda Gary G.
Evans F. L.
United States of America as represented by the Administrator of
Vrioni Beth A.
LandOfFree
Plant chlorophyll content meter does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Plant chlorophyll content meter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Plant chlorophyll content meter will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-939291