Method and apparatus for water level determination
First Claim
1. A system for determining the level of a body of water, whether free flowing or stationary, said system comprising:
- a rotatable reflective element including an inclined reflective surface;
a light source for directing a light beam along a first path onto said reflective surface so that the beam is reflected from said surface and redirected along a further path;
a motor for rotating said reflective element so that the redirected beam is scanned and so that, during scanning thereof, the redirected beam is directed onto the surface of the body of water such that at least a portion of the redirected beam is reflected from the surface as a reflected beam;
an optical detector array, physically unconnected to and located at a determined distance from said reflective element on the opposite side of the body of water from said reflective element, in a common horizontal plane with said reflective element, for receiving the reflected beam and for producing an output in response thereto; and
controller means for receiving said output of said optical detector array, for determining, based on said output, a determined scan angle of said reflected beam with respect to true vertical, at which the reflected beam is received by said optical detector array, and for calculating, based on said determined scan angle and the determined distance between the reflective element and the optical detector array, the distance from the common horizontal plane to the water surface so as to determine the water level, said controller means including a controller for receiving said output and for producing a corresponding control signal, and a counter controlled by said controller for, responsive to receiving said control signal, producing a scan angle count related to said scan angle.
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Accused Products
Abstract
A method and system are provided for determining the level of a body of water, whether free flowing or stationary. A rotatable reflective element is located at an area adjacent to the body of water. The reflective element is driven by a rotating motor shaft and includes a reflective surface extending 45° to the shaft axis. Rotation of the reflective surface provides scanning of a laser beam directed axially thereon. During scanning, the beam is directed at an angle to true vertical onto the surface of the body of water such that a portion of the beam is reflected from the surface. A detector array, located on the opposite side of the body of water and in a common horizontal plane with the reflective element, produces an output after receiving the reflected beam. A controller arrangement, including a counter which begins counting when-the scanned beam is vertical and which stops counting when a signal corresponding to the array output is received, determines the scan angle to true vertical. A simple calculation, based on the determined scan angle and the distance between the reflective element and the array, is then made of the distance from the common horizontal plane to the water surface so as to determine the water level.
13 Citations
19 Claims
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1. A system for determining the level of a body of water, whether free flowing or stationary, said system comprising:
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a rotatable reflective element including an inclined reflective surface;
a light source for directing a light beam along a first path onto said reflective surface so that the beam is reflected from said surface and redirected along a further path;
a motor for rotating said reflective element so that the redirected beam is scanned and so that, during scanning thereof, the redirected beam is directed onto the surface of the body of water such that at least a portion of the redirected beam is reflected from the surface as a reflected beam;
an optical detector array, physically unconnected to and located at a determined distance from said reflective element on the opposite side of the body of water from said reflective element, in a common horizontal plane with said reflective element, for receiving the reflected beam and for producing an output in response thereto; and
controller means for receiving said output of said optical detector array, for determining, based on said output, a determined scan angle of said reflected beam with respect to true vertical, at which the reflected beam is received by said optical detector array, and for calculating, based on said determined scan angle and the determined distance between the reflective element and the optical detector array, the distance from the common horizontal plane to the water surface so as to determine the water level, said controller means including a controller for receiving said output and for producing a corresponding control signal, and a counter controlled by said controller for, responsive to receiving said control signal, producing a scan angle count related to said scan angle. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method for determining the level of a body of water, whether free flowing or stationary, said method comprising:
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scanning a laser beam reflected at a variable angle to true vertical from a rotatable reflective element located at an area adjacent to but spaced from the body of water, so that the beam is directed onto the surface of the body of water during scanning and that at least a portion of the beam is reflected from the surface;
receiving the portion of the beam reflected from the surface with a detector array physically separated from, and located on the opposite side of the body of water from, and in substantially the same horizontal plane as, said reflective element;
determining the scan angle to true vertical at which the portion of the reflected beam is received by said detector array; and
using (i) the scan angle to true vertical so determined, and (ii) the distance between the reflective element and the detector array, to calculate the distance from said horizontal plane to the water surface so as to determine the water level, said scan angle being determined using a controller for producing a control signal when said detector array receives said reflected beam and a counter controlled by said controller for, responsive to receiving said control signal, producing a scan angle count related to said scan angle. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
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Specification