Altitude determining radar using multipath discrimination
First Claim
1. A height-determining radar, comprising a radar transmitter having a transmission site located at an altitude e above a reflecting surface, for emitting pulses of radiation;
- a radar receiver having a reception site in proximity to said transmission site for detecting said pulses of radiation reflected from a target located at an altitude h above said reflecting surface;
means for measuring the pulse width variation τ
B from pulse to pulse of said received pulses of radiation;
means for measuring the range R between said radar receiver reception site and said target; and
means for calculating h from the relationship between τ
B, R, e and h
space="preserve" listing-type="equation">h=cR τ
.sub.B /4e wherein c is the speed of light.
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Accused Products
Abstract
A height-determining radar utilizing both direct and multipath signals coising a radar transmitter and receiver and means for measuring the variation of the pulse widths of the received radar signal, the variation being caused by fluctuating multipath contribution to the received signal, and further comprising means for calculating the target height h from the equation h=cRτB /4e, where c is the speed of light, R is the target range, τB is the pulse width variation and e is the radar height. The multipath variation may be enhanced by varying the linear polarization of the emitted radar signal.
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Citations
10 Claims
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1. A height-determining radar, comprising a radar transmitter having a transmission site located at an altitude e above a reflecting surface, for emitting pulses of radiation;
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a radar receiver having a reception site in proximity to said transmission site for detecting said pulses of radiation reflected from a target located at an altitude h above said reflecting surface; means for measuring the pulse width variation τ
B from pulse to pulse of said received pulses of radiation;means for measuring the range R between said radar receiver reception site and said target; and means for calculating h from the relationship between τ
B, R, e and h
space="preserve" listing-type="equation">h=cR τ
.sub.B /4ewherein c is the speed of light. - View Dependent Claims (2)
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3. A height-determining radar, comprising:
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a radar transmitter having a transmission site located at an altitude e above a reflecting surface, for emitting pulses of radiation including means for varying the linear polarization of said emitted pulses from pulse to pulse; a radar receiver having a reception site coincident with said transmission site for detecting said pulses of radiation reflected from a target located at an altitude h above said reflecting surface; means for measuring the pulse width variation τ
B from pulse to pulse including an edge-triggered pulse duration circuit for comparing said pulse width variations;means for measuring the range R between said radar reception site and said target; and means for calculating said target altitude h from the relationship
space="preserve" listing-type="equation">h=cR τ
.sub.b /4ewherein c is the speed of light. - View Dependent Claims (4)
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5. A height-determining radar, comprising:
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a radar transmitter having a transmission site located at an altitude e above a reflecting surface, for emitting pulses of radiation, including means for varying the linear polarization of said emitted radiation from pulse to pulse; a radar receiver having a reception site coincident with said transmission site for detecting said pulses of radiation reflected from a target located at an altitude h above said reflecting surface; an edge-triggered pulse duration circuit for measuring the pulse width of said received pulses; means for determining the pulse width variation τ
B of said measured pulse widths from pulse to pulse;means for measuring the range R between said radar receiver reception site and said target; and means for calculating said altitude h from the equation
space="preserve" listing-type="equation">h=cR τ
.sub.B /4ewherein c is the speed of light, and generating a signal representative thereof. - View Dependent Claims (6, 7)
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8. A methdd for determining the altitude of a target, comprising the steps of:
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emitting a series of radar pulses from a transmission site located at an altitude e above a reflecting surface; detecting said series of radar pulses reflected from a target located at an altitude h above said reflecting surface at a reception site in proximity to said transmission site; measuring the pulse widths of said received radar pulses; measuring the pulse width variation τ
B of said measured pulse widths; andcalculating said altitude h from the equation
space="preserve" listing-type="equation">h=cR τ
.sub.B /4ewherein c is the speed of light and generating a signal representative thereof.
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9. A method for determining the altitude of a target, comprising:
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transmitting a series of radar pulses of substantially different linear polarizations from a transmission site located at an altitude e above a reflecting surface; detecting said series of radar pulses reflected from a target located at an altitude h above said reflecting surface at a reception site coincident with said transmission site; measuring the pulse widths of said received radar pulses; measuring the pulse width variation τ
B of said pulse widths;measuring the range R of said target from said transmitting site; and calculating said altitude h from the equation
space="preserve" listing-type="equation">h=cR τ
.sub.B /4ewherein c is the speed of light and generating a signal representative thereof. - View Dependent Claims (10)
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Specification