Patent US6232882B1 successfully refreshed from Google Patents.
US6232882B1
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US
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Warning system and method for detection of tornadoes
Assignee: Spectrum Electronics Inc
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Filing: 2000-07-19
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Granted: 2001-05-15
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Expires: 2020-07-19
Abstract
Abstract To differentiate between lightning strikes and tornado generated electromagnetic signals, a tornado detection system and method is made up of RF receiving circuits which receive signals at two frequencies, while implementing a time variable automated calibration and the use of special algorithms, to reliably detect tornado events and to signal an alarm. A network of such systems can be implemented, using a plurality of antennas which are capable of discerning a directional vector, and integrating the directional information from multiple units by effecting a triangulation calculation in a server terminal to determining a position and path of an approaching tornado.
Inventors
- 👤 Aharon Ze'ev Hed
- 👤 Richard Pavelle
- 👤 Sol Aisenberg
- 👤 George Freedman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 06:32
CPC Classifications
G; G01; G01W; G01W1/00; G01W1/10; G01W1/16; Y; Y02; Y02A; Y02A50/00
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
162 words
A system for detecting tornadoes, comprising: a first RF receiving circuit adapted to be connected to an antenna and comprising a resonant circuit tuned to receive an RF signal at a first predetermined frequency; a second RF receiving circuit adapted to be connected to an antenna and comprising a resonant circuit tuned to receive an RF signal at a second predetermined frequency; memory means storing a pair of predetermined threshold values and an algorithm to distinguish between an electromagnetic signature of a tornado, intermittent electromagnetic signals and manmade signals; and processing means connected to said first and second RF receiving circuits, for receiving respective amplitude signals indicating amplitudes of the RF signals at said first and second predetermined frequencies, said processing means further comprising means for applying said algorithm to said amplitudes of the RF signals at said first and second frequencies to detect a tornado, said processing means further comprising means to emit a signal when said algorithm detects a tornado.
Claim 2
Independent Claim
162 words
A system for detecting tornadoes, comprising: a first RF receiving circuit adapted to be connected to an antenna and comprising a resonant circuit tuned to receive an RF signal at a first predetermined frequency; a second RF receiving circuit adapted to be connected to an antenna and comprising a resonant circuit tuned to receive an RF signal at a second predetermined frequency; memory means storing a pair of predetermined threshold values and an algorithm to distinguish between an electromagnetic signature of a tornado, intermittent electromagnetic signals and manmade signals; and processing means connected to said first and second RF receiving circuits, for receiving respective amplitude signals indicating amplitudes of the RF signals at said first and second predetermined frequencies, said processing means further comprising means for applying said algorithm to said amplitudes of the RF signals at said first and second frequencies to detect a tornado, said processing means further comprising means to emit a signal when said algorithm detects a tornado.
Claim 3
Dependent Claim
22 words
The system according to claim 1 , further comprising alarm and/or display means and said emitted signal activates said alarm and/or display.
Claim 4
Dependent Claim
30 words
The system according to claim 1 , wherein said predetermined threshold values are continuously updated according to the background electromagnetic noise prevailing at the system site at said two frequencies.
Claim 5
Dependent Claim
84 words
The system according to claim 1 , wherein the algorithm comprises the steps of: comparing the RF amplitudes received at said two frequencies to their respective threshold values; updating said threshold value to exceed background noise and manmade signals at said frequencies; and determining the presence of a tornado if and only if both amplitudes are greater than their respective threshold values for a period greater than a predetermined time interval, said interval being longer than that of natural intermittent signals such as lightening.
Claim 6
Dependent Claim
25 words
The system according to claim 1 , wherein said first and second frequencies are both within a range of from 30 MHz to 60 MHz.
Claim 7
Dependent Claim
48 words
The system according to claim 5 , wherein said first frequency is set within a range of a frequency spectrum publicly used for carrying AM video image signals, and said second frequency is set within a range of the frequency spectrum publicly used for carrying FM audio signals.
Claim 8
Dependent Claim
25 words
The system according to claim 6 , wherein said first frequency is set at 55.25 MHz and said second frequency is set at 59.75 MHz.
Claim 9
Dependent Claim
72 words
The system according to claim 4 , wherein said processing means further comprises: means for sampling said respective amplitudes of said first and second frequencies for a predetermined sampling interval; and means for counting a predetermined number of consecutive sampling intervals during respective measurement cycles at which said RF amplitudes at said first and second frequencies exceed said predetermined threshold values, wherein said predetermined time interval is determined by said predetermined number.
Claim 10
Dependent Claim
18 words
The system according to claim 8 , wherein said sampling interval is between 0.1 ms and 50 ms.
Claim 11
Dependent Claim
14 words
The system according to claim 8 , wherein said respective amplitudes are sampled simultaneously.
Claim 12
Dependent Claim
25 words
The system according to claim 8 , wherein a standby time interval, during which sampling is not performed, occurs between sampling of said respective amplitudes.
Claim 13
Dependent Claim
33 words
The system according to claim 4 , wherein said threshold values comprise first and second threshold values each comprising the product of an average of previously received amplitude signals times a scaling constant.
Claim 14
Dependent Claim
111 words
The system according to claim 12 , further comprising default threshold values T 1 (d) and T 2 (d) associated with each of said first and second threshold values, wherein said first and second threshold values T 1 and T 2 are calculated according to the following equations: T 1 =max{ k 1 A a1 , T 1 ( d )} T 2 =max{ k 2 A a2 , T 2 ( d )} where k 1 and k 2 are scaling constants for each of said first and second threshold values, and A a1 and A a2 are respective averages of previously received amplitudes at said first and second frequencies.
Claim 15
Dependent Claim
42 words
The system according to claim 13 wherein said respective averages are updated during each measurement cycle, unless during the preceding measuring cycle said amplitude values for both of said first and second frequencies have exceeded the first and second threshold values, respectively.
Claim 16
Independent Claim
151 words
A method of detecting tornadoes by distinguishing the electromagnetic signature of a tornado from manmade signals and intermittent natural signals comprising the steps of: setting a first RF receiving circuit, adapted to be connected to an antenna and comprising a resonant circuit, to be tuned at a first predetermined frequency; setting a second RF receiving circuit, adapted to be connected to an antenna and comprising a resonant circuit, to be tuned at a second predetermined frequency; storing a pair of predetermined threshold values that are greater than present ambient manmade signals; receiving with said first and second RF receiving circuits, respective amplitude signals indicating amplitudes of the RF signals at said first and second predetermined frequencies; comparing said amplitude signals with said predetermined thresholds values; and emitting a signal indicating detection of a tornado when both of said amplitude signals exceed said predetermined threshold values for a predetermined duration of time.
Claim 17
Independent Claim
151 words
A method of detecting tornadoes by distinguishing the electromagnetic signature of a tornado from manmade signals and intermittent natural signals comprising the steps of: setting a first RF receiving circuit, adapted to be connected to an antenna and comprising a resonant circuit, to be tuned at a first predetermined frequency; setting a second RF receiving circuit, adapted to be connected to an antenna and comprising a resonant circuit, to be tuned at a second predetermined frequency; storing a pair of predetermined threshold values that are greater than present ambient manmade signals; receiving with said first and second RF receiving circuits, respective amplitude signals indicating amplitudes of the RF signals at said first and second predetermined frequencies; comparing said amplitude signals with said predetermined thresholds values; and emitting a signal indicating detection of a tornado when both of said amplitude signals exceed said predetermined threshold values for a predetermined duration of time.
Claim 18
Dependent Claim
25 words
A method according to claim 15 , further comprising an alarm means and/or display means, and said signal activates said alarm means and/or display means.
Claim 19
Dependent Claim
30 words
A method according to claim 15 , wherein said predetermined threshold values are continuously updated according to the background electromagnetic noise prevailing at the system site at said two frequencies.
Claim 20
Dependent Claim
25 words
The method according to claim 15 , wherein said first and second frequencies are both within a range of from 30 MHz to 60 MHz.
Claim 21
Dependent Claim
68 words
The method according to claim 15 , further comprising the steps of: setting said first RF receiving circuit to be tuned to said first frequency within a range of a frequency spectrum used publicly for carrying AM video image signals; and setting said second RF receiving circuit to be tuned to said second frequency within a range of the frequency spectrum used publicly for carrying FM audio signals.
Claim 22
Dependent Claim
25 words
The method according to claim 19 , wherein said first frequency is set at 55.25 MHz and said second frequency is set at 59.75 MHz.
Claim 23
Dependent Claim
65 words
The method according to claim 15 , further comprising the steps of: sampling said respective amplitudes of said first and second frequencies for a predetermined sampling interval; and counting a predetermined number of sampling intervals during respective measurement cycles at which both of said first and second frequencies exceed said predetermined threshold values, wherein said predetermined duration of time is determined by said predetermined number.
Claim 24
Dependent Claim
18 words
The method according to claim 21 , wherein said sampling interval is between 0.1 ms and 50 ms.
Claim 25
Dependent Claim
14 words
The method according to claim 21 , wherein said respective amplitudes are sampled simultaneously.
Claim 26
Dependent Claim
25 words
The method according to claim 21 , wherein a standby time interval, during which sampling is not performed, occurs between sampling of said respective amplitudes.
Claim 27
Dependent Claim
42 words
The method according to claim 17 , further comprising setting said threshold values as first and second threshold values, wherein said first and second threshold values each comprise the product of an average of previously received amplitude signals times a scaling constant.
Claim 28
Dependent Claim
113 words
The method according to claim 25 , further comprising the steps of: setting default threshold values T 1 (d) and T 2 (d) associated with each of said first and second threshold values; calculating said first and second threshold values T 1 and T 2 according to the following equations: T 1 =max{ k 1 A a1 , T 1 ( d )} T 2 =max{ k 2 A a2 , T 2 ( d )} where k 1 and k 2 are scaling constants for each of said first and second threshold values, and A a1 and A a2 are respective averages of previously received amplitudes at said first and second frequencies.
Claim 29
Dependent Claim
45 words
The method according to claim 26 , further comprising the step of updating respective averages during each measurement cycle, unless during a prior measuring cycle said amplitude values for both of said first and second frequencies have exceeded the first and second threshold values, respectively.
Claim 30
Independent Claim
272 words
A system for detecting tornadoes, comprising: a plurality of tornado detectors, wherein each of said tornado detectors comprises: a first RF receiving circuit adapted to be connected to an antenna and comprising a resonant circuit tuned to receive an RF signal at a first predetermined frequency; a second RF receiving circuit adapted to be connected to an antenna and comprising a resonant circuit tuned to receive an RF signal at a second predetermined frequency; memory means storing a pair of predetermined threshold values and an algorithm to distinguish between an electromagnetic signature of a tornado, intermittent electromagnetic signals and manmade signals; and processing means connected to said first and second RF receiving circuits, for receiving respective amplitude signals indicating amplitudes of the RF signals at said first and second predetermined frequencies, said processing means further comprising means for applying said algorithm to said amplitudes of the RF signals at said first and second frequencies to detect a tornado, said processing means further comprising means to emit a signal when said algorithm detects a tornado; a digital communications network interconnecting said RF receiving units and a server terminal, wherein said tornado detectors each further comprise processing means for determining the direction of maximum signal, when a tornado is detected, and means for emitting a signal indicating a directional vector at which an amplitude of the RF signal is maximum, and wherein said directional vectors from each of said tornado detectors are transmitted through said communications network to said server terminal, said server terminal having means for determining an intersection of at least two directional vectors for detecting a position of the detected tornado.
Claim 31
Independent Claim
272 words
A system for detecting tornadoes, comprising: a plurality of tornado detectors, wherein each of said tornado detectors comprises: a first RF receiving circuit adapted to be connected to an antenna and comprising a resonant circuit tuned to receive an RF signal at a first predetermined frequency; a second RF receiving circuit adapted to be connected to an antenna and comprising a resonant circuit tuned to receive an RF signal at a second predetermined frequency; memory means storing a pair of predetermined threshold values and an algorithm to distinguish between an electromagnetic signature of a tornado, intermittent electromagnetic signals and manmade signals; and processing means connected to said first and second RF receiving circuits, for receiving respective amplitude signals indicating amplitudes of the RF signals at said first and second predetermined frequencies, said processing means further comprising means for applying said algorithm to said amplitudes of the RF signals at said first and second frequencies to detect a tornado, said processing means further comprising means to emit a signal when said algorithm detects a tornado; a digital communications network interconnecting said RF receiving units and a server terminal, wherein said tornado detectors each further comprise processing means for determining the direction of maximum signal, when a tornado is detected, and means for emitting a signal indicating a directional vector at which an amplitude of the RF signal is maximum, and wherein said directional vectors from each of said tornado detectors are transmitted through said communications network to said server terminal, said server terminal having means for determining an intersection of at least two directional vectors for detecting a position of the detected tornado.
Claim 32
Dependent Claim
19 words
The system according to claim 28 , wherein said antennas associated with each tornado detector comprise directional loop antennas.
Claim 33
Dependent Claim
36 words
The system according to claim 28 , wherein at least one of said tornado detectors is mobile and the said threshold values associated with each said tornado detector are updated at least once every 5 seconds.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-05-14 | 2004-11-13 | 2005-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-05-14 | 2008-11-13 | 2009-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-05-14 | 2012-11-13 | 2013-05-15 | $7700.00 | Window Closed / Lapsed |