Patent US4595925A successfully refreshed from Google Patents.
US4595925A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Altitude determining radar using multipath discrimination
Assignee: United States Department of the Navy
•
Filing: 1983-03-28
•
Granted: 1986-06-17
•
Expires: 2003-03-28
Abstract
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=cRτ B /4e, where c is the speed of light, R is the target range, τ B 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.
Inventors
- 👤 James P. Hansen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:48
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/02; G01S13/06; G01S13/46
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
117 words
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 h=cR τ.sub.B /4e wherein c is the speed of light.
Claim 2
Dependent Claim
117 words
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 h=cR τ.sub.B /4e wherein c is the speed of light.
Claim 3
Dependent Claim
52 words
A height-determining radar, as recited in claim 1, wherein said means for measuring τ B comprises an edge-triggered pulse duration circuit for measuring the pulse width of said received pulses of radiation and means for comparing said measured pulse widths from pulse to pulse for said pulse width variation τ B .
Claim 4
Dependent Claim
131 words
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 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 h=cR τ.sub.b /4e wherein c is the speed of light.
Claim 5
Dependent Claim
131 words
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 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 h=cR τ.sub.b /4e wherein c is the speed of light.
Claim 6
Dependent Claim
33 words
A height-determining radar, as recited in claim 3, wherein said pulse width variation τ B is the magnitude of the difference of the pulse width between pulses of radiation having orthogonal linear polarizations.
Claim 7
Dependent Claim
144 words
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, 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 h=cR τ.sub.B /4e wherein c is the speed of light, and generating a signal representative thereof.
Claim 8
Dependent Claim
144 words
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, 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 h=cR τ.sub.B /4e wherein c is the speed of light, and generating a signal representative thereof.
Claim 9
Dependent Claim
26 words
A height-determining radar, as recited in claim 5, wherein the difference of the pulse widths is the difference between the widths of pulses of different polarizations.
Claim 10
Dependent Claim
35 words
A height determining radar, as recited in claim 6, wherein said pulse width variation τ B is limited to the magnitude of the maximum difference between the pulse widths of any of said received pulses.
Claim 11
Dependent Claim
106 words
A methdd for determining the altitude of a target, comprising the steps of: 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; and calculating said altitude h from the equation h=cR τ.sub.B /4e wherein c is the speed of light and generating a signal representative thereof.
Claim 12
Dependent Claim
106 words
A methdd for determining the altitude of a target, comprising the steps of: 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; and calculating said altitude h from the equation h=cR τ.sub.B /4e wherein c is the speed of light and generating a signal representative thereof.
Claim 13
Independent Claim
117 words
A method for determining the altitude of a target, comprising: 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 h=cR τ.sub.B /4e wherein c is the speed of light and generating a signal representative thereof.
Claim 14
Independent Claim
117 words
A method for determining the altitude of a target, comprising: 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 h=cR τ.sub.B /4e wherein c is the speed of light and generating a signal representative thereof.
Claim 15
Dependent Claim
43 words
A method for measuring the altitude of a target, as recited in claim 9, wherein said step of measuring said pulse width variation τ B comprises the step of comparing the pulse width of said radar pulses transmitted with substantially different linear polarizations.
References Cited (Backward Citations)
US3014215A
Cited
US2837738A
Cited
US3714654A
Cited
US4090197A
Cited
US4386355A
Cited
US4370656A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-06-16 | 1989-12-16 | 1990-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-16 | 1993-12-16 | 1994-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-16 | 1997-12-16 | 1998-06-17 | $7700.00 | Window Closed / Lapsed |