Method and apparatus for remote detection and thickness measurement of ice or liquid layer
OwnerRobert E. Gagnoninventor
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Abstract
There is described a method and apparatus for detection and thickness evaluation of a buildup of ice or liquid on a solid surface, especially on a body of an aircraft. The apparatus comprises a source of a narrow beam of radiation and a means for remote evaluation of the size of a luminous area created on the solid surface by the beam. The method of the invention involves measuring the size of the luminous area and determining the thickness of any built-up layer, if sufficiently transparent, using a formula which uses the dependency of the size of the luminous are on the thickness of the layer and the refraction index of the medium. Differentiation between ice and a liquid is possible by evaluating regularity of illumination of the luminous area.
Claims10
An apparatus for remote thickness evaluation of a substantially transparent layer of ice or a liquid on a substantially smooth surface, the apparatus comprising:
- a source of electromagnetic radiation for emitting a narrow beam of radiation towards the surface to be examined in a manner to create, in the presence of an ice layer or a liquid layer on the surface, a luminous multi-zone area on the surface, and
- a remote detecting means for determining the size of the luminous multi-zone area as a function of the thickness of the ice layer or the liquid layer.
A method of remote non-contact thickness evaluation of a substantially transparent layer of ice or a liquid on a substantially smooth surface, comprising the steps of:
- directing a narrow beam of electromagnetic radiation onto the layer of ice or liquid in a manner to create on the surface a luminous multi-zone area,
- measuring the size or diameter D of the luminous area, and
- determining the thickness H of the layer of ice or liquid from the size or diameter D of the luminous area by way of the formula
- H=D/4 tan .alpha.
- where
- .alpha.=sin.sup.-1 (1/n)
- n being the refractive index of ice or of the liquid.
A method of remote non-contact detection and optional thickness evaluation of a substantially transparent layer of ice or liquid on a substantially smooth solid surface, comprising the steps of:
- directing a narrow beam of electromagnetic radiation onto the layer of ice or a liquid in a manner to create on the surface, in the presence of such layer, a luminous area having at least two zones, including a bright centre zone and a darker second zone, and
- determining whether the layer is a liquid or ice by evaluating the regularity of illumination of at least one of said zones.
Dependencies are inferred from the claim text.