Patent US4887088A successfully refreshed from Google Patents.
US4887088A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signal processing and radio ranging system
Assignee: MBDA UK Ltd
•
Filing: 1988-11-23
•
Granted: 1989-12-12
•
Expires: 2008-11-23
Abstract
Abstract A radio slant ranging system having a bank of range gates producing outputs X I to X N which comprise ground clutter components on a thermal noise pedestal. The clutter components are regarded as defining a single sinusoidal ripple envelope on the noise pedestal and a clutter centroid tracking signal is derived by using a digital filter to calculate the real and imaginary components A 1R and A 1I of the transform: ##EQU1## and then forming the arctangent of A 1I /-A 1R . The signal processing method used in the system may have general application.
Inventors
- 👤 Andrew R. Beckett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:35
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/02; G01S13/50; G01S13/58; G01S13/583; G01S13/584; G01S13/06; G01S13/08; G01S13/32; G01S13/34; G01S13/341; G01S13/64
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
112 words
A method of radio ranging comprising the steps of: receiving a radar return signal; discriminating the radar return signal to form a plurality N of range channel signals X 1 to X N representative of return signal components associated with respective ones of N consecutive range cells; and determining the location of the centroid of a peak in the ripple envelope defined by the range channel signals by filtering those signals to form the real and imaginary components A 1R and A 1I , respectively, of the A 1 transform of a discrete Fourier transform: ##EQU7## and then calculating a range error signal from the arctangent of A 1I /-A 1R .
Claim 2
Independent Claim
112 words
A method of radio ranging comprising the steps of: receiving a radar return signal; discriminating the radar return signal to form a plurality N of range channel signals X 1 to X N representative of return signal components associated with respective ones of N consecutive range cells; and determining the location of the centroid of a peak in the ripple envelope defined by the range channel signals by filtering those signals to form the real and imaginary components A 1R and A 1I , respectively, of the A 1 transform of a discrete Fourier transform: ##EQU7## and then calculating a range error signal from the arctangent of A 1I /-A 1R .
Claim 3
Dependent Claim
135 words
A radio ranging system comprising; receiver means for receiving a radar return signal; discriminating means connected to the receiver means for discriminating the radar return signal to form a plurality N of range channel signals X 1 to X N representative of components of said return signal associated with respective ones of N consecutive range cells; filter means connected to the discriminating means for forming respective signals representative of the real and imaginary components A 1R and A 1I , respectively, of the A 1 transform of a discrete Fourier transform: ##EQU8## and calculating means connected to the filter means for calculating a range error signal from the arctangent of A 1I /-A 1R so as to determine the location of the centroid of a peak in the envelope defined by the range channel signals.
Claim 4
Dependent Claim
135 words
A radio ranging system comprising; receiver means for receiving a radar return signal; discriminating means connected to the receiver means for discriminating the radar return signal to form a plurality N of range channel signals X 1 to X N representative of components of said return signal associated with respective ones of N consecutive range cells; filter means connected to the discriminating means for forming respective signals representative of the real and imaginary components A 1R and A 1I , respectively, of the A 1 transform of a discrete Fourier transform: ##EQU8## and calculating means connected to the filter means for calculating a range error signal from the arctangent of A 1I /-A 1R so as to determine the location of the centroid of a peak in the envelope defined by the range channel signals.
Claim 5
Dependent Claim
161 words
A radio ranging system for use on board an airborne weapon to determine the slant range from the weapon to the ground, the system comprising: radar means for illuminating the ground and for receiving clutter returns from the ground; range gate means connected to the radar means for discriminating the clutter returns to form a plurality N of range channel signals X 1 to X N representative of clutter returns received from within respective ones of N range cells; and centroid locating means connected to the range gate means for determining the location of the centroid of a peak in the ripple envelope defined by the range channel signals, said centroid locating means comprising filter means for forming respective signals A 1R and A 1I , respectively, of the A 1 transform of a discrete Fourier transform: ##EQU9## and calculating means connected to the filter means for determining a range error signal from the arctangent of A 1I /-A 1R .
Claim 6
Dependent Claim
161 words
A radio ranging system for use on board an airborne weapon to determine the slant range from the weapon to the ground, the system comprising: radar means for illuminating the ground and for receiving clutter returns from the ground; range gate means connected to the radar means for discriminating the clutter returns to form a plurality N of range channel signals X 1 to X N representative of clutter returns received from within respective ones of N range cells; and centroid locating means connected to the range gate means for determining the location of the centroid of a peak in the ripple envelope defined by the range channel signals, said centroid locating means comprising filter means for forming respective signals A 1R and A 1I , respectively, of the A 1 transform of a discrete Fourier transform: ##EQU9## and calculating means connected to the filter means for determining a range error signal from the arctangent of A 1I /-A 1R .
References Cited (Backward Citations)
US31509A
Cited
US4232315A
Cited
US3889261A
Cited
US4028700A
Cited
USRE31509E
Cited
US4079377A
Cited
US4042925A
Cited
US4176351A
Cited
US4567484A
Cited
US4665401A
Cited
US4388622A
Cited
US4450444A
Cited
US4536763A
Cited
US4639733A
Cited
US4620192A
Cited
US4637941A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-12-11 | 1993-06-12 | 1993-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-11 | 1997-06-12 | 1997-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-11 | 2001-06-12 | 2001-12-12 | $7700.00 | Window Closed / Lapsed |