Active Imaging Systems for Plant Growth Monitoring

Patent metadata

Field	Value
Publication number	US-2015379702-A1
Application number	US-201414319075-A
Country	US
Kind code	A1
Filing date	Jun 30, 2014
Priority date	Jun 30, 2014
Publication date	Dec 31, 2015
Grant date	—

Abstract

Active imaging systems for plant growth monitoring acquire images in which each pixel represents an absolute NDVI value obtained with active illumination.

First claim

1 . An active imaging system for plant growth monitoring comprising:
a light emitter capable of emitting light at two or more wavelengths, the light emitter receiving a modulation signal from a modulator and emitting light modulated by the modulation signal; a first lens that projects light from the light emitter onto a crop and a second lens that images an area of the crop onto an array of sensor pixels, each pixel of the array of sensor pixels receiving the modulation signal from the modulator and detecting light from the light emitter after the light has been reflected by the crop, thereby obtaining a reflectivity measurement of the crop; and, a processor that computes a vegetative index based on reflectivity measurements obtained at two or more different wavelengths.

2 . The system of claim 1 , the vegetative index being a normalized difference vegetative index,

NDVI
=

r
NIR

-

r
VIS

r
NIR

+

r
VIS

,

where r NIR and r VIS are crop reflectivity measurements obtained at infrared and visible wavelengths, respectively.

3 . The system of claim 1 , the second lens being an anamorphic lens.

4 . The system of claim 1 , the processor comprising logic included in the array of sensor pixels.

5 . The system of claim 1 , the processor comprising an ASIC, FPGA or microprocessor, external to the array of sensor pixels.

6 . The system of claim 1 , the array of sensor pixels comprising 10,000 or more pixels.

7 . The system of claim 1 , the light emitter comprising a first light emitting diode that emits light at a visible wavelength and a second light emitting diode that emits light at an infrared wavelength.

8 . The system of claim 1 , the light emitter comprising a first diode laser that emits light at a visible wavelength and a second diode laser that emits light at an infrared wavelength.

9 . The system of claim 1 further comprising optical bandpass filters for each of the two or more wavelengths.

10 . A method for plant growth monitoring comprising:
a light emitter emitting light at two or more wavelengths, the light emitter receiving a modulation signal from a modulator and emitting light modulated by the modulation signal; a first lens projecting light from the light emitter onto a crop and a second lens imaging an area of the crop onto an array of sensor pixels; each pixel of the array of sensor pixels receiving the modulation signal from the modulator and detecting light from the light emitter after the light has been reflected by the crop, thereby obtaining a reflectivity measurement of the crop; and, a processor computing a vegetative index based on reflectivity measurements obtained at two or more different wavelengths.

11 . The method of claim 10 , the vegetative index being a normalized difference vegetative index,

NDVI
=

r
NIR

-

r
VIS

r
NIR

+

r
VIS

,

where r NIR and r VIS are crop reflectivity measurements obtained at infrared and visible wavelengths, respectively.

12 . The method of claim 10 , the second lens being an anamorphic lens.

13 . The method of claim 10 , the processor comprising logic included in the array of sensor pixels.

14 . The method of claim 10 , the processor comprising an ASIC, FPGA or microprocessor, external to the array of sensor pixels.

15 . The method of claim 10 , the array of sensor pixels comprising 10,000 or more pixels.

16 . The method of claim 10 , the light emitter comprising a first light emitting diode that emits light at a visible wavelength and a second light emitting diode that emits light at an infrared wavelength.

17 . The method of claim 10 , the light emitter comprising a first diode laser that emits light at a visible wavelength and a second diode laser that emits light at an infrared wavelength.

18 . The method of claim 10 , the crop comprising a plurality of plants and the second lens imaging an area of the crop onto the array of sensor pixels such that each pixel receives light from more than one plant.

19 . The method of claim 10 , the crop comprising a plurality of plants and the second lens imaging an area of the crop onto the array of sensor pixels such that each pixel receives light from less than one plant.

20 . The method of claim 10 , the crop comprising a plurality of plants and the second lens imaging an area of the crop onto the array of sensor pixels such that there is a one-to-one correspondence between plants and pixels.

Assignees

• Ulman Morrison
• Trimble Navigation Ltd

Inventors

• Ulman Morrison

Classifications

• G06T7/0004

  Industrial image inspection · CPC title

• G06V20/188 Primary

  Vegetation · CPC title

• H04N23/56

  provided with illuminating means · CPC title

• B64U2101/30

  for imaging, photography or videography · CPC title

• H04N23/11

  for generating image signals from visible and infrared light wavelengths · CPC title