Abstract:
The present invention features a system and method for detecting and predicting lightning strikes via specialized electrostatic detection using highly sensitive atmospheric static electric detection, interpretation, and alarm signal distribution. The system employs a detection means which includes a designated lightning sensor having a surface which carries a high impedance static voltage reference charge. This reference charge, called the pilot voltage, is a static charge delivered to the lightning sensor at very low currents. The pilot voltage influences the relative charge in the molecules found in the atmosphere immediately surrounding the lightning sensor. There is a gradual transition in the charge between the lightning sensor&#39;s surface and the molecules in the atmosphere that surrounds the sensor. It is this varying molecular state that creates a modulation process which the present invention uses to determine a lighting strike.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to electrical detector circuitry, and more particularly, to an apparatus for detecting lightning. 
     2. Discussion of the Prior Art 
     The prior art is replete with devices that attempt accurate detection of lightning in the atmosphere. For example, the U.S. Patent to Murtha, Jr., et al., issued Nov. 2, 1999, (U.S. Pat. No. 6,061,216) for a Lightning Detection Apparatus and Methodology makes use of an antenna and amplifier configuration for receiving electrostatic discharges of lightning and electrical noise to output an analog electrical signal representative of the discharge. This analog signal is applied to a threshold detection circuit whose output is activated when the input signal rises above a predetermined level. Herein a computer or similar device examines the output to determine an open event window. It is the pulses of the event window that are given signatures which are compared. If the pulse signature correlates with that of lightning, then an alert signal is generated. 
     The U.S. Patent to Fuqua, III, U.S. Pat. No. 6,061,216, issued May 9, 2000, teaches of the protection of electrical or electronic equipment from lightning. The device detects amplitude modulation RF signals emitted from an electrical storm, via a detector which sends energy to signal a trigger relay to activate an internal timer and relay systems to disconnect the device, thereby protecting it from lightning damage. 
     In U.S. Pat. No. 6,246,367, to Markson, et al., for a Lightning Locating System, a device is disclosed that detects the initial discharge of the leader stroke of a lightning flash. Sensors are employed that use time difference of arrival information to determine the range of an initial lightning discharge. 
     The U.S. Patent to Guerra (U.S. Pat. No. 6,038,118) issued Mar. 14, 2000, is for a Lightning Protector System. A radio frequency detector assembly, which receives input from an antenna and a line sensor, senses signatures of electrical environmental events, such as lightning strikes and transient line events caused by power grid loss, etc. This protector circuit uses a central processing unit (CPU) to isolate the equipment from the volatile power grid and switches the power source to a local storage cell device. 
     The U.S. Patent to Young (U.S. Pat. No. 5,923,516) issued Jul. 13, 1999, is for an Apparatus for Protecting Electrical and Electronic Equipment and Associated Method. Herein, another protection apparatus is disclosed which includes a device that is switchable between a protected state and an operating site. The apparatus protects the electrical equipment form disturbances carried by the external electrical conductors. 
     The Distributed Lightning Detection System disclosed in U.S. Pat. No. 5,699,245, to George issued on Dec. 16, 1997, teaches of a plurality of lightning detection stations located at different positions with respect to a common frame of reference, with the position of at least one detection station being mobile. Each station includes a lightning strike detector, first and second receivers, a processor, and a transmitter. The receivers are adapted to receive signals from the GPS system for establishing a common lightning position and occurrence time from a point of reference for all stations. The transmitter reports strikes over a data link to other lightning detectors and provides this data to the central processor. The processor correlates received strike reports with detected strike reports to determine reports generated from common lightning strikes and computes a range from the station to each of the common lightning strikes based on the data of the correlated strike reports corresponding thereto. 
     The disclosed Incipient Lightning Detection and Device Protection device of Young, U.S. Pat. No. 5,521,603, issued May 28, 1996, teaches of an apparatus that continuously and automatically protects electrical devices from potential threats of damaging voltage levels. This apparatus employs the use of a detector for detecting a threat, and a protection switching circuit for grounding the electrical device and the detector upon detection. 
     Smith et al., disclose a Method and Apparatus for Predicting Lightning Threats Based on Radar and Temperature Data, patented on Jun. 11, 2002 as U.S. Pat. No. 6,405,134, teaching of a system for predicting areas where lightning strikes are likely to occur by evaluating radar and temperature data. Radar volume data is analyzed to locate cloud tops that extend above a height corresponding to a particular temperature line. Areas where cloud tops extend above the height of −10 degrees C and that have a radar composite reflectivity greater than 30 bDZ are designated as probable lightning threat areas. Radar movement is tracked across at least two time periods and a correlation algorithm predicts the future location of lighting threat areas at predetermined time periods based on predicted radar values. Then, a computer display shows predicted locations where lightning damage is likely to occur. 
     None of these patents either teaches or suggests the detection of molecular changes in the atmosphere using a plate sensor carrying a static, pilot voltage with a high impedance to determine the probability of a lightning strike or determines a prediction of local lightning activity within a one-half mile range. 
     SUMMARY OF THE INVENTION 
     The present invention features a system and method for detecting and predicting lightning strikes via specialized electrostatic detection using highly sensitive atmospheric static electric detection, interpretation, and alarm signal distribution. The system employs a detection means which includes a designated lightning sensor having a surface which carries a high impedance static voltage reference charge. This reference charge, called the pilot voltage, is a static charge delivered to the lightning sensor at very low currents. The pilot voltage influences the relative charge in the molecules found in the atmosphere immediately surrounding the lightning sensor. There is a gradual transition in the charge between the lightning sensor&#39;s surface and the molecules in the atmosphere that surrounds the sensor. It is this varying molecular state that creates a modulation process which the present invention uses to determine a lighting strike within a one-half mile radius. The actual static voltage on the lightning sensor&#39;s plate surface will be brought back to the original set pilot voltage value as prescribed by software and hardware settings of the system. 
     It is therefore an object of the invention to provide a system and method for detecting and predicting lightning strikes. 
     It is another object of the invention to provide a 
     a system and method for accurately predicting lightning strikes for at least a one-half mile radius. 
     It is also an object of the invention to provide a 
     system for detecting lighting strikes by detecting atmospheric changes on an electro-molecular level for efficiently detecting lighting strikes. 
     It is a further object of the invention to provide 
     a method and system for accurate lightning strike detection and prediction with a two-level alarm system for notification to avoid disasters. 
     It is an additional object of the invention to provide a system and method that overcomes very short alarm indication problems by sensing the actual lightning conditions for a local lightning strike. 
     These and other objects, features and advantages will be more apparent from a study of the enclosed text and the appended drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A complete understanding of the present invention may be obtained by reference to the accompanying drawings, when taken in conjunction with the detail description thereof and in which: 
     FIG. 1 is an environmental perspective of the lightning prediction and alarm device. 
     FIG. 2 is a schematic diagram showing an embodiment of the sensor electronics in accordance with the present invention. 
     FIG. 3 is a schematic diagram showing an alternate embodiment of the sensor electronics wherein capacitive coupling is employed, in accordance with the present invention. 
     FIG. 4 is a schematic diagram showing an alternate embodiment of the sensor electronics wherein digital to analog conversion means are employed, in accordance with the present invention. 
     FIG. 5 is a schematic diagram showing an alternate embodiment of the sensor electronics wherein a micro-controller is employed, in accordance with the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     This disclosure of the invention is submitted in furtherance of the constitutional purposes of the U.S. Patent Laws “to promote the progress of science and useful arts” (Article 1, Section 8). 
     Generally speaking this invention relates to a lightning detection and prediction alarm device  10  (LDPAD) as shown in FIG.  1 . During an electrical storm, the electrical dynamics of the atmosphere become unsettled and turbulent. The normal average static charge in the air begins to swing to more negative and positive potentials. Lightning creates a shock wave effect on the average static charge in the atmosphere&#39;s relative electric state, creating a static voltage spike. These spikes trigger the LDPAD  10  to send a lightning detection alarm signally. 
     Rapid changes in the charge in the atmosphere are a result of local discharges of lightning bolts in a more rapid positive to negative charge swings relative to the ground. This rapid change is detected by the sensor electronics  300  which in turn send a lightning detection alarm signal by a strobe light  105 . In a preferred embodiment, the strobe light  105  is used to indicate the presence of lightning nearby and the audible horn  140  is used if conditions warrant a lightning prediction. A rapid change in the negative charge level in the atmosphere indicates a lightning prediction audible alarm signal via audible horn  140 . 
     The LPDAD  10  is located outdoors, embedded in the earth&#39;s surface  200 . The LPDAD  10  is supported by an external housing support  110 . Located atop of housing  110  is the Ion Charge Plate Sensor (ICPS)  100 , which is used to sense the electrical activity in the atmosphere. The LPDAD  10  is preferably located away from trees, buildings and other objects to maximize sensitivity of the ICPS  100  being able to sense very faint and natural static electrical charges contained in the molecules of the atmosphere. The atmosphere&#39;s static charge level is constantly changing the static charge on the ICPS&#39;s  100  surface. 
     The natural static charge level contained in the immediate atmosphere surrounding the ICPS  100  may be affected by the relative humidity, temperature, the sun, the lack of sunlight, local electrical noise generated by electrical power, humans and animals walking by, and other natural phenomena. 
     An insulated coaxial cable  132  supplies the plate sensor  100  with the static pilot voltage. Coaxial cable  132  also electrically couples the plate sensor  100  with the sensor electronic circuitry  300  (discussed in detail below). A weatherproof housing support  110  is used as the structural support for the system  10 . 
     FIGS. 2-5 are schematic diagrams further illustrating the electronic components of the LPDAD  10 . The ICSP  100  may be coupled to the sensor electronics  300  by either capacitive coupling or resistive coupling. FIG. 2 shows an embodiment of resistive coupling between the ICPS  100  and the sensor electronics  300 . Alternatively, FIG. 3 shows an embodiment wherein ICPS  100  is capacitive coupled. Although FIGS. 4 and 5 illustrate resistive coupling, it may be appreciated by those of ordinary skill in the art that capacitive coupling (as in the FIG. 3 embodiment) may be likewise employed. 
     Since it is known that the natural atmosphere can be more positively or negatively charged at any time, it is of utmost importance to stabilize the circuit relative to the pilot voltage applied to the ICPS  100 . For example, after sunset, in the summer local atmospheric static electricity assumes a more positive charge as negative ions decrease. This local atmospheric static electricity also changes due to season and climatic changes. This stabilization is performed by a very high mega ohm resistor. The shape of the ICPS  100  allows the circuitry of the sensor electronics  300  to be as immune to RF frequencies as possible, thereby picking up on the electrostatic component of electrical activity. 
     The circuitry of the sensor electronics  300  allows for constant and slow achievement of equilibrium, wherein equilibrium is defined around the value of the pilot voltage. The sensor electronics circuitry  300  allows for the rejection of unwanted signals by filtering them out. The ICPS&#39;s  100  actual surface electrical static charge level is the product resulting from the ICPS  100  regulated static charge level maintained by the pilot voltage in conjunction with the static charge level of the ICPS&#39;s  100  surface. 
     In the presence of an electric storm, a negative, static charge signature is produced. This change is characterized by an increasing, stepped ladder of electricity. This negative, static electrical charge signature is detected via the Static Charge Level Logic Control (SCLLC)  350 . The PILOT VOLTAGE CONTROL CIRCUITRY  350  automatically controls the pilot voltage level changes to slowly maintain this nominal static voltage value (equilibrium) in response to the ongoing gradual changing normal ion average electrical level which occurs from day to night and from season to season. 
     These gradually changing ion electrical values do not represent electrical turbulence characteristic of lightning. It is this nominal, equilibrium value that the PILOT VOLTAGE CONTROL CIRCUITRY  350  regulates. The ion atmospheric charge potential is collected on the ICPS&#39;s  100  metal surface and either this ion charge adds to or subtracts form the normal charge bias which is applied to the charged ICPS  100 . Rapid changes in the ICPS  100  bias level indicates the presence of electrical turbulence in the vicinity of the LPDAD  10 . This nominal charge bias is supplied by the coaxial cable  132  via the sensor circuitry  300  and not the ICPS  100 . 
     These changes are amplified using an N-channel FET device, or other amplifier device. In the preferred embodiment of this invention, the changes are amplified by a very high impedance MOSFET transistor  305 . MOSFET  305  greatly amplifies the charge potential located on the ICPS  100  in order to expand the variations in voltage potential electrically and to supply these voltages to the comparator. 
     The nominal pilot voltage level across the MOSFET&#39;s  305  drain D is maintained to develop a drain voltage at a desired level. In some embodiments, this level may be in the range of 1-8 volts, with respect to the earth&#39;s ground, however this value may vary greatly depending on the model specifications. The source voltage potential S of the FET  305  is of a specific value above the ICPS&#39;s  100  common ground (not shown) which is not the earth&#39;s common ground  150 . The FET&#39;s  305  source S is grounded to the Earth&#39;s ground  150  to use as a stable reference. Furthermore, the MOSFET&#39;s  305  gate node is buffered by a gas lamp  302  which serves as in a transient protector and a high voltage short-switch. The gas lamp  302  may be a neon gas lamp. 
     In operation, if the voltage appearing at the FET&#39;s  305  drain D becomes more positive, relative to a desired voltage, the ICPS  100  has become more negatively charged due to the interaction of more negatively charged ions from the atmosphere surrounding the LPDAD  10 . If the voltage appearing at the FET&#39;s drain becomes more negative, relative to a desired voltage, the ICPS  100  has become more positively charged due to the interaction of more positively charged ions from the atmosphere surrounding the LPDAD  10 . 
     The electrical signature of lightning would result in quick, positive leading, increasing voltage spikes appearing on the FET&#39;s  305  gain G followed immediately by a negative spike. This rapid more positive voltage on the FET&#39;s  305  gate G causes an amplified, much lower impedance signal in reverse (more negative) to appear at the FET&#39;s  305  drain D, which is then processed for alarm monitoring. This electrical atmospheric signature indicates a lightning discharge detection. 
     A rapid increase of more positive voltage across the FET&#39;s  305  drain D indicates a much higher level of negatively charged ions surrounding the ICPS  100 , which is transferred to the FET&#39;s  305  gate G. This electrical atmospheric signature indicates a very highly charged cloud in the vicinity. 
     Both a rapid negative voltage spike along with a more generally positive voltage appearing on the FET&#39;s  305  drain D, is representative of an electrical atmospheric signature indicative of the two conditions indicating lightning activity. This signature indicates both a high electrical turbulence activity in the clouds in the nearby vicinity and its highly charged state, signifying the danger of the high possibility of a local lightning strike. 
     Local lightning strikes are more of an AC-induced voltage type of electricity, while the presence of a pending lightning strike is more of a negative DC voltage charge. Hence, a notch filter  306  filters out any AC and RF interferences traversing the sensor circuitry  300 . The amplified filtered signals are divided into resistive and capacitive components by R/C Delay  307  and distributed to the inputs of an analog quad IC comparator  308 . 
     The comparator  308  compares the real-time changes of the pilot voltage levels to a stable reference in order to increase the amount of electrical turbulence being received by the ICPS  100 . The sensor circuitry  300  is designed to allow for the rejection of unwanted signals by filtering them out. It is the effect that lightning has on the atmosphere that the LPDAD  10  is sensitive to. The processing of these signals is performed by the pilot voltage control circuitry  350  in one of several ways. 
     The pilot voltage control circuitry  350  may analyze the signals by analog comparator circuitry as shown in FIG.  2 . In an alternate embodiment, a Digital Analog Converter (DAC)  352  with binary up/down counters  353  as shown in FIG. 4 may be employed. Further, a microcontroller  351  may be utilized, as shown in FIG.  5 . Additionally, the microcontroller  352  may be used in conjunction with the analog comparators. The microcontroller  351  uses a pre-set voltage value in firmware to automatically present the voltage reference level at around an equilibrium point. 
     The LPDAD  10  has two levels of lightning alarm conditions, in the preferred embodiment. For the first level, a flashing strobe light  105  indicates that active lightning is within a range of 25 to 300 miles radius, more or less, as adjusted in the field. This range may vary depending on several variables, including but not limited to, the sensor electronics  300  and coupling of the ICPS  100 . For the second level of alarm, a flashing strobe light  105  and audible alarm  140  indicates that a local lightning strike is highly likely in the immediate area. 
     In the non-microcontroller embodiment of the LPDAD  10  (e.g., FIGS.  2 - 4 ), four fixed CMOS  555  timers  312   a-d  are used to create the timing of the alarm indications. Two of the timers  312  are used for timing the duration of each of the two alarm indicators (strobe  105  and siren  140 ) at a designated time. In a preferred embodiment, this time is set at about 2 minutes for lightning detection before reset and twelve seconds for audible lightning prediction alarm. 
     However, it is understood by those of ordinary skill in the art that this time may vary. A third timer is used to inhibit the siren  140  for about 2 minutes from recurring within the 2 minute time-out. The fourth timer is used for the visible flashing LED lamp  400  and to indicate normal operation in an automatic tracking mode. However, in normal operation, flashing LED lamp  400  will only flash when alarm timers  312   a-d  are armed and working and in active signal standby as the LDPAD  10  will stay in an off-standby mode if it has just been turned on by the atmospheric acquisition sensory circuit  149 . This delay may be about 2 minutes allowing the LPDAD  10  to stabilize the pilot voltage delivered to the ICPS  100 . 
     The LPDAD  10  also includes an automatic nighttime shut-off mechanism as a part of circuit  149  which can be used to shut down the LPDAD  10  at night. This mechanism employs the use of a temperature sensor  148  as well as a solar panel  120 . Temperature sensor  148  is used to detect temperatures which preclude the possibility of a lightning storm. Solar panel  120  is equipped with solar cells  125  for receiving photonic energy from the sun&#39;s radiation. This energy is then stored in an on-site battery compartment  128 . Battery compartment  128  may consist of a series of batteries adapted to store electrical energy for reserve power needs. 
     Since other modifications and changes varied to fit a particular operating requirements and environment will be apparent to those skilled in the art, the invention is not considered limited to the example chosen for purposes of disclosure, and covers all changes and modifications which do not constitute a departure from the true spirit and scope of the invention. 
     Having thus described the invention, what is desired to be protected by Letters Patent is presented in the subsequent appended claims.