ICE AND WATER DETECTION SYSTEM
First Claim
1. A system for detecting ice and/or water within an area of interest, said system comprising:
- a detection system measuring radiance or reflectance of the area of interest when exposed to electromagnetic radiation having wavelengths in a spectral band containing a crossover point in the curves describing the absorption of electromagnetic radiation by ice and water, said detection system measuring said radiance or reflectance in a first band having wavelengths in a spectral band on a first side of said crossover point (band λ
1) and outputting a first band signal (Rλ
1), said detection system measuring said radiance or reflectance in a second band having wavelengths in a spectral band on a second opposing side of said crossover point (band λ
2) and outputting a second band signal (Rλ
2); and
a processing unit determining a ratio of said first band signal and said second band signal (γ
=Rλ
1/Rλ
2), said processing unit comparing said ratio to predetermined critical ratio ranges and outputting a determination signal indicating at least one of presence of ice when said ratio is within a first range of said predetermined critical ratio ranges and presence of water when said ratio is within a second range of said predetermined critical ratio ranges.
1 Assignment
0 Petitions
Accused Products
Abstract
A system for detecting ice or water within an area of interest having a detection system measuring radiance or reflectance of the area of interest when exposed to shortwave infrared radiation having a wavelength in the range containing a crossover point between the curves representing the absorption of electromagnetic radiation by ice and water. The detection system measures the radiance or reflectance in a first band having a wavelength in a spectral band on a first side of the crossover point and outputting a first band signal, and further measures the radiance or reflectance in a second band having a wavelength in a spectral band on a second opposing side of the same crossover point and outputting a second band signal. A processing unit determines a ratio of the first band signal and the second band signal and compares the ratio to a predetermined critical ratio and outputs a determination signal indicating presence of ice or water.
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Citations
21 Claims
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1. A system for detecting ice and/or water within an area of interest, said system comprising:
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a detection system measuring radiance or reflectance of the area of interest when exposed to electromagnetic radiation having wavelengths in a spectral band containing a crossover point in the curves describing the absorption of electromagnetic radiation by ice and water, said detection system measuring said radiance or reflectance in a first band having wavelengths in a spectral band on a first side of said crossover point (band λ
1) and outputting a first band signal (Rλ
1), said detection system measuring said radiance or reflectance in a second band having wavelengths in a spectral band on a second opposing side of said crossover point (band λ
2) and outputting a second band signal (Rλ
2); anda processing unit determining a ratio of said first band signal and said second band signal (γ
=Rλ
1/Rλ
2), said processing unit comparing said ratio to predetermined critical ratio ranges and outputting a determination signal indicating at least one of presence of ice when said ratio is within a first range of said predetermined critical ratio ranges and presence of water when said ratio is within a second range of said predetermined critical ratio ranges. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A method for detecting ice within an area of interest, said method comprising:
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measuring a first radiance of the area of interest at a first spectral band in a spectral band on a first side of a crossover point (Rλ
1);measuring a second radiance of the area of interest at a second spectral band on a second opposing side of said crossover point (Rλ
2);calculating a radiance ratio of said first radiance and said second radiance (γ
=Rλ
1/Rλ
2); anddetermining whether said radiance ratio is within a predetermined critical radiance ratio range (γ
crit1<
γ
<
γ
crit2),if said radiance ratio is within said predetermined critical radiance ratio range then determining if a specular reflection is present by determining if said first radiance is greater than a predetermined critical radiance and outputting an ice-present warning.
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19. A method for detecting supercooled liquid water droplets within an area of interest, said method comprising:
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measuring a first radiance of the area of interest at a first spectral band in a spectral band on a first side of a crossover point (Rλ
1);measuring a second radiance of the area of interest at a second spectral band on a second opposing side of said crossover point (Rλ
2);calculating a radiance ratio of said first radiance and said second radiance (γ
=Rλ
1/Rλ
2); anddetermining whether said radiance ratio is within a predetermined critical radiance ratio range (γ
crit1<
γ
<
γ
crit2),if said radiance ratio is within said predetermined critical radiance ratio range then measuring a temperature of the area of interest and determining if said temperature is within a predetermined critical temperature range and outputting a supercooled-liquid-water-droplets-present warning.
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20. A method for detecting supercooled large droplets (SLD) within an area of interest, said method comprising:
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measuring a first radiance of the area of interest at a first spectral band on a first side of a crossover point (Rλ
1);measuring a second radiance of the area of interest at a second spectral band on a second opposing side of said crossover point (Rλ
2);calculating a radiance ratio of said first radiance and said second radiance (γ
=Rλ
1/Rλ
2); anddetermining whether said radiance ratio is greater than a predetermined critical radiance ratio range (γ
=crit1<
γ
<
γ
crit2),if said radiance ratio is within said predetermined critical radiance ratio range then calculating a droplet effective radius and determining if said droplet effective radius is greater than a predetermined critical droplet radius and outputting a supercooled-large-droplets-present warning.
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21. A method for detecting water substance within an area of interest, said method comprising:
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measuring a first radiance of the area of interest at a first spectral band (band λ
1) on a non-absorbing band (Rλ
1);measuring a second radiance of the area of interest at a second spectral band (band λ
2) on an absorbing band (Rλ
2);calculating a radiance ratio of said first radiance and said second radiance (γ
=Rλ
1/Rλ
2); anddetermining whether said radiance ratio is within predetermined critical radiation ranges (γ
=crit1<
γ
<
γ
crit2),if said radiance ratio is within said predetermined critical radiance ratio characteristic of ice, liquid water or snow, then outputting a signal indicating the presence of one of these substances, including their mixtures.
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Specification