KR20080065658A - Detection of lightning - Google Patents

Abstract

A lightning detector for lightning detection and a lightning detection method, wherein the mobile lightning detector is provided with an antenna, an amplifier front-end, an A/D converter and a digital signal processor, and wherein the lightning detector is a mobile RF device provided with an audio codec whereby the preamplifier of the codec is used for amplification of the detected lightning signal, the A/D converter of the codec is used for the A/D conversion of the amplified lightning signal, and whereby the digital audio processing unit of the codec is used for the signal processing of the lightning detection.

Description

Detection of lightning

The present invention relates to a lightning detector. In particular, the present invention relates to a mobile lightning detector provided with an antenna, an amplifier front-end, an A / D converter, and a digital signal processor. It is about. The invention also relates to a method of detecting lightning.

Thunderstorms are a major weather hazard, but are difficult to predict. It travels at speeds of 20 km / h to 40 km / h, and lightning strokes can occur at a distance of more than 10 km ahead of the rain clouds, and some distance behind them. Lightning strikes are generated by clouds or weather fronts, but in fact most dangerous lightning strikes occur when there is no cloud visible above as a warning for thunderstorms. Thus, if there is a system that warns of the possibility of harmful thunderstorms, approximately 10 minutes before thunderstorms can be seen, it may be considered a major safety concern.

There are many people who can benefit from such safety considerations. For some, it can only be provided as informative daily information. For many people, however, threats from storms and lightnings will have significant implications for property loss, increased risk or fatal consequences. For example, people who spend a lot of time outdoors, astronauts, navigators, etc. have a special interest in lightning alert systems. Even when the weather appears to be perfectly calm and clear, a system that provides warnings of lightning can enable a person to take safety measures, such as seeking shelter and the like at the right time.

Although many single-purpose lightning detectors are known in the prior art, they have some disadvantages in commercial terms.

Scientific lightning detectors used in meteorology are very large and span hundreds of kilometers.

High-end lightning detectors, which also use a single radio frequency (RF) band, are large and relatively expensive compared to mobile telephones, for example. In addition, they generally need to be oriented on a wall or tabletop stand to have a specific orientation, for example, in order to achieve the desired accuracy or directionality. Thus, they are not suitable for use in true mobility. Moreover, typically these devices should be placed vertically and stably supported for a few minutes until the detection of thunderstorms is reliable.

Furthermore, there are currently low performance lightning detectors that are completely portable in size, do not require a particular orientation and are relatively inexpensive. However, these detectors are very vulnerable to electromagnetic emissions related to electromagnetic compatibility (EMC) and therefore tend to generate false alarms, especially in cities or near highways.

The present invention contemplates that lightning strikes are not only visual signals and partially audible pressure signals, but also a single flash that generates electromagnetic pulses over short but strong and widely varying wavelengths. depart. Typical electromagnetic pulses caused by lightning strike are distributed at frequencies between 10 Hz and 5 GHz, ie, audio frequency range, with peaks approximately 500 Hz. At a normalized distance of 10 km, the amplitude of such pulses ranges from 107 mV / m to 1 mV / m at a bandwidth of 1 kHz. The strongest signal of the electromagnetic pulse is the induced electric field caused by the vertical current in the lightning strike, which is the most commonly measured parameter in large equipment that detects the bearing and distance of lightning.

However, due to the complexity of the lightning phenomena, there are strong signals in the extremely low frequency (ELF) range of several hundred Hz or less, and weak signals in the range of GHz and above.

Since the related meteorological mechanisms are slightly different, it is well understood that the time spectrum and exact characteristics of the electromagnetic interference (EMI) signature in the MHz range differ from those in the kHz and Hz range. It is a known fact.

However, for the purposes of the present invention, it is sufficient to note that lightning strikes involve an electromagnetic interference pulse that can be identified at a place several kilometers away for all frequencies of interest.

As a result of the electromagnetic interference pulse, the RF channel is briefly interrupted during nearby lightning strikes. Disturbance to RF receivers due to electromagnetic interference caused by lightning strikes can be caused by static, clicks, scratches, pictures, by AM / FM radios, TVs, or power lines. It may be experienced in the form of picture interference, or loss of sound. Disturbance in radio frequency channels caused by lightning strikes can be detected over very long distances. Specialized and large-scale lightning detectors can detect so-called sferics at a distance of several hundred kilometers from lightning strikes, but these detectors are typically radio frequency signals, as in the present invention. Or it works by measuring the induced electric field rather than measuring interference in the audio signal.

Common AM radios are known to suffer from electromagnetic interference from lightning strikes at distances of up to 30 km or more, which may be heard directly in the audio signal as various clicks. At frequencies higher than the AM bands (SW, LW, MW), it is common for the signal to be much weaker due to atmospheric attenuation and different causation mechanisms, but nevertheless can be detected over long distances. have.

In known mobile wireless devices, such as ordinary mobile telephones, electromagnetic interference in a received radio frequency signal is immediately removed by filtering or as a result of the adopted modulation, but is observed in the present invention ( It is proposed to evaluate such electromagnetic interference in a monitored radio frequency channel. When the detected interference appears to be caused by lightning strikes, for example, an alarm can be sounded to the user of the mobile telephone. For example, when the interference exceeds a predetermined threshold or when it has a frequency spectrum that is characteristic of a lightning strike, it may be assumed that the interference is caused by the lightning strike. The detection of lightning can be on as long as radio frequency detection is on.

Thus, the present invention can be implemented in a mobile wireless device such as, for example, a mobile phone, and provides new safety features.

In many cases, the desire to detect nearby lightning strikes will not be large enough to bear the difficulty and cost of carrying a dedicated lightning detector, but in any case is already carried by the device, especially the mobile phone. A low cost detection system integrated into a device such as would be appreciated. The known art does not provide for the integration of detection of lightning as a new function in known mobile wireless devices.

In most known commercial lightning detectors, electromagnetic signals from lightning are detected in relatively low frequency bands, i.e., audio frequencies, compared to radio frequencies. Audio codecs in mobile wireless devices typically amplify signals from 40 to 60 dB in bandwidths up to 48 kHz, so audio codecs amplify signals from lightning detection front-ends. And may be used for further processing. The audio codec also includes a high quality A / D converter, which can be used for lightning detection. In addition to amplification and A / D conversion, some portions of the digital audio processing blocks in the codec may be used for signal processing in lightning detection.

Therefore, according to one aspect of the present invention, the present invention provides a function as a lightning detector based on using an audio codec in a mobile wireless device.

According to a first aspect of the invention there is therefore provided a lightning detector, which is a mobile wireless device provided with an audio codec, the preamplifier of the codec amplifying the detected lightning signal. The codec's A / D converter is used for A / D conversion of the amplified lightning signal, and the digital audio processing unit of the codec is used for signal processing of lightning detection. Is used.

In a preferred embodiment of the invention, the lightning detection front-end is in parallel with the microphone such that the microphone input of the audio codec is used jointly by lightning detection and other applications. Connected.

In a second preferred embodiment of the present invention, the microphone input is used as the lightning detection front-end interface, which microphone input would not have been used if not.

According to another embodiment of the present invention,

The speech codec of the mobile wireless device is utilized for lightning detection, the A / D converted lightning signal is processed in the speech codec path, and the symbols detected and output by the speech codec are digital signal processing ( Analyzed in terms of lightning detection using digital signal processing (DSP).

According to another embodiment of the invention, the amplification path of the audio codec is used in conjunction with the AM or FM radio receiver of the mobile wireless device in lightning detection.

According to another embodiment of the present invention, lightning detection is performed as a detection combination on at least two frequency channels.

According to another embodiment of the invention, there are at least two microphone inputs available for lightning detection, the lightning detection being performed in two different audible frequency bands.

According to another embodiment of the present invention, two orthogonally arranged antenna coils are used to implement a detector capable of detecting the direction of lightning.

According to another embodiment of the invention, the wireless device comprises means for determining the orientation of the mobile wireless device at the point of lightning strike.

According to another embodiment of the invention, detected lightning strike information including an event time is stored in a memory to determine an estimated lightning distance from a mobile device.

According to another embodiment of the present invention, a mobile wireless device may store additional weather information received from a network in the storage device.

According to another embodiment of the present invention, weather information may be displayed on a display indicating relative, true direction to intensity, distance, and thunderstorm.

The features of the lightning detector and method of detecting lightning according to the invention are set out in detail in the appended claims.

The present invention makes it possible to create an integrated system utilizing existing architectures, modules, and signal processing or computational capabilities within a mobile wireless device.

Furthermore, when the amplification path and possibly other parts of the audio codec in the mobile wireless device are used for lightning detection, the cost and space required are significant because no extra hardware is required for lightning detection. Is reduced.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

1 is a schematic block diagram of a system according to the invention.

2 shows the frequency spectrum of the electromagnetic signal caused by lightning at a distance of 10 km.

3 shows an exemplary circuit of microphone (MIC) input circuitry, where the microphone circuit is divided by a microphone and a lightning detection front-end.

4 shows an implementation of a lightning detection front-end at an audible frequency.

Embodiments of how two lightning detection antenna coils can be used are shown in FIGS. 5A-5C: detection at two different frequencies is shown in FIG. 5A, and two orthogonal in FIG. 5B. Detection and direction estimation using coils are shown, and omni-directional detection is shown in FIG. 5C.

6 shows a propriatory port used for mobile wireless terminals, a removable functional cover of the mobile terminal, and a battery charging coil used for lightning detection, and / or an RFID coil used for lightning detection. Is shown.

7A and 7B show two orientations of the lightning detection antennas, where FIG. 7A shows that the orientation of the antenna is vertical, and FIG. 7B shows that the orientation of the antenna is horizontal.

In FIG. 8, an ambiguous forward / backward detection situation is schematically illustrated.

1 is a schematic block diagram of a cellular communication system capable of lightning warning in accordance with the present invention. The system may be for example a GSM system.

The cellular communication system includes a cellular phone 10 and a base station 20 of a cellular communication network.

The mobile phone 10 includes a receiving RX antenna 11, which is connected to a microprocessor 13 via a radio frequency module 12. The mobile phone 10 further includes a microphone 14 and a speaker 15 as well as an audio codec 16 for the formation of an audio amplification path, A / D conversion, and further digital signal processing of the audio signal. The microprocessor 13 is also connected to the display unit 17. This indicator may be partitioned 18 for multiple applications. The mobile phone may further comprise an electronic compass 19, a storage device 21 partitioned for a plurality of applications. Cell phone 10 also includes other components that are not shown but are known to be included in conventional cell phones.

As shown in FIG. 2, most of the electromagnetic energy emitted by the lightning is at a frequency close to 5 to 10 kHz (ie, audible frequency). Therefore, it is reasonable to perform lightning detection at relatively low frequencies. However, the man-made EMC level is highest at such low frequencies but rapidly fades with frequency, thus using a somewhat higher lightning detection frequency, or alternatively first using a higher detection frequency. It is advantageous to downconvert to baseband so that lightning detection can be made without interference from artificial EMC.

The present invention is based on using the audio codec of the mobile telephone 10 as an amplification path for A / D conversion and digital processing of lightning signals in lightning detection. The technical idea is to connect an antenna (e.g. a coil) or a front-end 31 comprising a plurality of components or frequency converting means necessary for lightning detection by using an input 34 of an audio codec. will be. The lightning detection front end 31 can be connected in parallel with the microphone, so that the microphone input 32 of the audio codec 35 has two applications, namely the lightning detection front end 31 and the microphone 14. It is shared by (see FIG. 3).

Alternatively, a microphone input that is not used for other purposes may be dedicated to the lightning detection front-end. To obtain sufficient performance characteristics, depending on the performance of the audio coded, filtering and amplification may be required at the lightning detection front-end before the signal is input to the audio codec.

Analog lightning detection signals from the front-end are amplified and A / D converted in the audio codec. The audio codec also includes an analog or digital filter. After A / D conversion and filtering, the lightning detection signal may be analyzed using a digital signal processing (DSP) method, and the information about the detected lightning may be analyzed by the user interface of the device (i.e., display and / or). Speaker).

An audio codec with one or several microphone inputs may be utilized, for example, by jointly using a headset accessory and an input by a lightning front-end. Alternatively, the lightning detector front-end accessory may be attached to the same input / output connector (eg, POP port) used for the headset and handsfree accessory. Such a propriatory Nokia POP connector is shown as 63 in FIG. 6. All accessories attachable to the Nokia POP port can include any circuitry (ACI chip), which stores the parameters necessary for optimal use of the DSP. By using the parameters in the ACI, the DSP is configured to better support the use of accessories attached to the POP port.

Alternatively, the lightning detector front-end accessory may be included in the functional cover 62 of the portable terminal 60, which may be removed by the user, or contactless charging using the battery charging coil (s) 61. It may be embedded in a circuit used for.

One issue in terms of implementation is the implementation of lightning detection antennas at audible frequencies. Traditionally, antennas have been implemented as separate coils. However, coils require a great deal of area and space, and therefore it is essential to find an effective way to implement coil (s) in the target device. In the present invention, the amplification path of the audio codec may be used in conjunction with the auxiliary coil or coils 61 used for inductive battery charging.

The lightning detection front-end may be implemented on audio frequencies, for example as shown in FIG. 4. The lightning detection antenna coil L and the front-end may be embodied, for example, in the topology presented. Coil (L) and capacitor (C) form a band-pass filter, and diodes (D ₁ , D ₂ ) have gain stage (from too large voltage peak). This is necessary to protect the gain stage. To obtain sufficient gain in the entire amplification path, an optional operational amplifier stage 41 with gain setting resistors R1, R2 may be needed before the signal can be routed to the route towards the audio codec. .

Low-end lightning detector designs typically have a gain of 76 dB in the detection frequency band. Since known audio codecs typically have a gain of 34 to 59.5 dB, additional amplification may be necessary to obtain sufficient gain in the entire amplification path. However, it may be possible to achieve sufficient gain for lightning detection on an audible frequency without additional amplification path of the audio codec.

It may also be possible to utilize speech codec in lightning detection. A / D converted lightning signals can be processed using the voice codec path, and symbols output and detected by the voice codec can be analyzed in terms of lightning detection using the digital signal processing (DSP) method. have. Other combinations of audio circuits 51 and 52 and voice codec 53 may be utilized to analyze the lightning signal. The advantage of using a speech codec in the detection of lightning is that the speech codec is usually not used for a long time and therefore its utilization rate is increased.

Alternatively, the amplification path of the audio codec may be used in conjunction with an AM or FM radio receiver for lightning detection. It has been mentioned above that the present invention is based on detection on an audible frequency, but the detection can also be made on higher frequencies such as AM radio frequency (150 kHz-30 MHz) and FM radio frequency (87.5-108 MHz). This is possible by down-converting the high frequency signal to an audible frequency with a down-converter. Best results will be obtained by detection combinations on two or more frequency channels that are sufficiently far from each other. Some detection and ranging methods are based on different attenuations of lightning noise at different frequencies, and therefore two or more receivers in combination will provide a better estimate regarding the distance to lightning activity within a thunderstorm.

Further, to detect and classify lightning signals, use the front-end of an AM or FM radio receiver and use an audio codec coding (TX) path as part of the detection chain. It is possible to detect the signal from lightning by using the produced code as an input for a digital signal processing (DSP) method or by using the same codec decoding (RX) path for this purpose.

If more than one microphone inputs are available, lightning detection can be done on two different audio frequency bands, which makes the detection and analysis more accurate. See FIG. 5A for the principle of implementation. Two orthogonally arranged antenna coils 54, 55 can be used to implement the detector, which can also detect the direction of lightning (see FIG. 5B). Direction detection is based on a comparison of the levels received from orthogonal coils. In addition, two coils may be used to obtain the omnidirectional lightning detector (see FIGS. 5A-5C). The omnidirectional detector is implemented by using separate channels for signals 54 and 55 from coils L1 and L2 as in FIG. 5B, or the signals from the two coils are combined together as in FIG. 5C. After getting through 58, possibly filtering in filter 59, it can be analyzed as a signal. Of course, the combined signal from summer 56 does not give any information about the direction of the lightning strike. Even when using orthogonal coils as shown in Fig. 8, the determination of the direction is unclear. Without an additional antenna, it is impossible to determine whether the signal is received from the front direction 81 or from the rear direction 82. However, by combining weather information received from the network, or simply having the user enter the wind direction, this ambiguity can be resolved. One coil or two coils shown in FIGS. 5A-5C may be inductive charging coils, similar to the charging coil 61 of FIG. 6. Otherwise, the coils may be coils used for some other purpose, for example for the purpose of RFID.

The audio codec used in the present invention may be of a type generally used in mobile wireless devices and commercially available. Such audio codecs include, for example, a UEME comprising a microphone input stage consisting of inputs for three signals, a 3/1 multiplexer, and a differential microphone amplifier, And the TLV320AIC23B from Texas Instruments, a stereo audio codec with an integrated headphone amplifier.

The present invention may include the technical idea for improving the current consumption and measurement performance of the device by utilizing the orientation of the detector device. Referring to FIGS. 7A and 7B, both the horizontal orientation 72 and the vertical orientation 73 of the detection antenna are shown.

Since the antenna gain of the loop antennas varies significantly as a function of the angular position with respect to the radio frequency source 71, the orientation of the detector can be used to improve the range of detection and / or directional measurement performance.

In virtually all known lightning detection devices that rely on the detection of the magnetic component H of the magnetic field, there is one coil or two orthogonal coils used to receive the radiofrequency signals emitted by the lightning strike. Since radiation from lightning is strongest at frequencies below 50 MHz, the only alternative receiving antenna alternative that can be integrated into a mobile device is basically a small loop antenna.

One major characteristic of the coil antenna is the directivity pattern. The pattern looks similar to donuts 74 and 75, the axis of which is parallel to the axis of the ferrite core 76. If only one detection antenna is used for the detection, the situation is similar to the situation shown in Figs. 7A and 7B. Variation in angular attitude to detected lightning strikes results in a deviation of 10 to 30 dB with respect to the induced signal. This deviation occurs when the axis of the coil is kept horizontal. If the axis has a vertical orientation, the derived signal may even be less than 30 dB relative to the optimal orientation.

If only one coil antenna is used, the main difficulty in estimating the distance (and the detection itself) is that the antenna gain changes with the receiving direction of the emission. In theory, when radio frequency emissions from lightning are received, the gain may vary from 0 dB (angle 0 ° or 180 °) to, for example, -30 dB (angle 90 ° or 270 °) depending on the angle of reception. have. If the antenna gain changes significantly (between two successive measurements) and there is no attitude information, is the deviation of the amplitude dependent on the radial distance between the storm and the detector, or is it of the detector that causes the deviation in the antenna gain? It is very difficult to find out if it is the amplitude deviation caused by the angular change (using only one coil antenna).

This embodiment describes a device that can be carried in a hand with at least one magnetic coil, and some method of determining the orientation of the device. The latter method may be manual (the user needs to determine the orientation of the device). Combination is used to provide a better distance estimate for the lightning source (and possibly to find a direction).

Once the orientation is known, the directionality problem of the coil can be solved or at least minimized. In addition, a quick change in orientation can be used to detect conditions in which accurate measurements are not possible.

The technical idea of the present invention is to utilize the attitude, orientation, and / or motion information of the lightning detector to compensate for the non-idealities of the antenna used to detect radio frequency emissions from lightning strikes. Since radio frequency emissions from lightning strikes are mostly vertically polarized and most intense at low frequencies (<100 MHz), they are the most space-effective to be used in receiving low frequency pulses. The solution is a small loop antenna. High directionality is a typical feature of small loop antennas, so the level of the received signal varies much depending on the orientation of the antenna relative to its source.

If a suitable or optimal detection posture for a lightning detector can be defined and some other orientations are very impractical, the device may move greatly (ie the antenna gain changes rapidly) or the device's orientation is not suitable for detection. It is not reasonable to detect lightning when it is not (ie, the antenna gain is small). In such a situation, for example, the lightning detector can be turned off for power saving, and the detection can continue after the device is kept stationary or in a more optimal orientation from the point of view of lightning detection.

In practice, it is not essential how the orientation information of the device is identified. The easiest way would be to measure azimuth by using magnetometer or accelerometer sensors, which would be applied to a mobile detector in the same way as the fluxgate compass 19 shown in FIG. Will be integrated. In practical use, tilt compensation should be made for this compass in order to enable use in a plane other than the horizontal plane without loss of direction accuracy. Another viable alternative is to obtain an indication as input by the user from the user interface as to the orientation of the device in terms of lightning detection, which may be combined with such weather information received from the network when there is additional weather information. It is also intended to be related.

The basic technical idea of the present embodiment can be utilized in many individual embodiments, and different detection principles are described in the following embodiments. The list begins with the simplest embodiments, and more complex combinations are listed at the end of the list of embodiments. The typical characteristic of a small loop antenna is valid in all embodiments, and information from sensors or other sources (eg from a user) indicating the orientation or attitude of the device is used in various ways.

In the simplest and possible embodiment, azimuth and / or motion detectors are used to determine if the device is stationary. The measurement is only made when the device is floating, since the gain is constant.

The simplest embodiment of the invention utilizes only information as to whether or not the detector remains floating. Since the radiation pattern of the coil antenna is directional, the detection environment cannot be considered constant if the device is moving. If an implementation of a simple lightning detection algorithm, for example, requires the device to be floating, such as some commercial lightning indicators, then an indication of the movement of the detector device is needed. .

If the detector is moving and there is uncertainty in the detection accuracy, the detection function can be turned off. Another alternative is to be in triggering mode, where only static lightning-like pulses are detected and for example distance measurements are taken.

If one or two coil antennas are used to receive the radio frequency emissions from the lightning strike, an optimal attitude may be defined in terms of detection. The optimal orientation may be the orientation where the axes of the coil antennas are horizontal. This is because when the most intense radiation is polarized vertically, the axis of the antenna coil is nearly vertical and the coupling between the lightning channel and the antenna coil is small (or the connection from the lightning channel is more inconsistent than the vertical one). (in the case of origin from horizontal channel components) means that there is no value in detecting or measuring lightning.

In practical cases this is a two-dimensional device (e.g., when the detector device is held in the bag / bag with its side lying down (in this case it has a zero value in the direction in which the main signal arrives). In other words, the detector device including only one coil) becomes unavailable.

In a more advanced implementation (i.e., an implementation comprising two orthogonal coils with two separate receive channels) one of the channels may be turned off when the detection orientation is not practical (switch-off ( switch off).

As already shown in FIG. 7B, the orientation in which the axis of the coil antenna is vertical is not the most useful in terms of lightning detection. The channel of lightning is typically vertical, and therefore the radio frequency emission from the lightning can be considered primarily vertically polarized. If the axis of the coil antenna is not horizontal, its connected signal strength can be compensated for by using an angle.

In a mobile device with a user interface, it is possible to instruct the user to move the device and to set the orientation optimally. The optimal orientation is the orientation with the least interference. This assumes that there is a local source of interference (such as a fluorescent lamp). In other words, the detector device is positioned so that the interference source is in a direction parallel to the coil axis.

If more accurate distance estimation is desired, the user may be prompted to maintain the detector in two orthogonal poses. This actually creates a "virtual orthogonal coil pair" using only one coil. In an implementation using one coil, the distance can be estimated in the two different postures, for example, from two consecutive lightning strikes.

The measurement situation is similar to that described with respect to FIGS. 7A and 7B. The detector device is guided to maintain the two orthogonal orientations shown in FIGS. 7A and 7B. An algorithm that needs to accurately measure the distance to consecutive lightning strikes may require several detected lightning strikes in both orientations. The user can be guided to reorient his device according to the estimation and detection algorithm.

If the lightning detector utilizes two (or three) orthogonal coils as receive antennas, the direction information for lightning strikes may be obtained. However, if only the correlations of the signals from the orthogonal coils are used, the use of only two orthogonal coils leaves 180 ° of uncertainty in the direction measurement for the storm (lightning strikes 81 or If it occurs at position 82 the detected signal will be similar). Direction information can be obtained by using three coils.

If the detector can define the direction information for the center of the lightning or storm, the orientation information of the detection can be used to collect the orientation data of the device during successive measurements, and the direction to the lightning will be obtained more accurately. Can be.

As a suggestion to overcome the 180 ° uncertainty in defining the direction to lightning, in many cases it is already sufficient information if the directions 83, 84 where no lightning is occurring can be defined. will be. Another alternative is to enter the wind direction. In either case, if the user moves in the direction 83 or 84, the user is likely to have more time to avoid an approaching storm or to find a shelter. Of course, the direction estimate may be updated when the storm approaches or goes away in the future.

One embodiment uses two modes, with a triggering mode that launches when any interference (interference that may be related to lightning, at least) is found. The triggering mode then activates a real sensing mode and, if necessary, changes the display mode according to the selection. The user is instructed to set the orientation of the device correctly (e. G. Flat on the table). Distance estimates are made only when this orientation is correct.

If it is assumed that the user is in some constant motion, that angle covers all possible angles and the gain parameter is removed. This requires a fairly long time for good statistical evaluation. A simple variant of this allows the user to rotate the device several times on the table so that most angles are covered. In particular, if the user keeps the device in one orientation for a while and then changes by 90 degrees, the minimum and maximum gains can be covered.

Finally, the front-end may be integrated into a mobile wireless device, but it may be a separate indicator device or may be integrated outside of the wireless device, such as the so-called functional cover 62 shown in FIG. 6, for example. It may be. The functional cover, which may be modified by such a user and includes the lightning detection front-end 31, may be sold as an accessory.

Those skilled in the art will clearly appreciate that different embodiments of the present invention are not limited to the examples described above, but may be modified within the scope of the appended claims.

The present invention can be used in a lightning detector.

Claims (27)

A mobile lightning detector with an antenna, amplifier front-end, A / D converter, and digital signal processor, The lightning detector is a mobile wireless device provided with an audio codec, the preamplifier of the codec is used to amplify the detected lightning signal, and the A / D converter of the codec is amplified. And a digital audio processing unit of the codec used for signal processing of lightning detection, wherein the signal is used for A / D conversion of the lightning signal. The method of claim 1, A lightning detection front-end is connected in parallel with the microphone so that the microphone input of the audio codec is jointly used by lightning detection and other applications. Lightning detector. The method of claim 1, A mobile lightning detector, characterized in that a microphone input that would not be used is used as a lightning detection front-end interface. The method of claim 1, Speech codec of the mobile wireless device is utilized for lightning detection, A / D converted lightning signal is processed in the voice codec path, and symbols detected and output by the voice codec are digital signal processing. A mobile lightning detector, characterized in that it is analyzed in terms of lightning detection using signal processing (DSP). The method of claim 1, The amplification path of the audio codec is used in conjunction with the AM or FM radio receiver of the mobile radio for lightning detection, and these high frequency signals are down-converted to an audible frequency by a down-converter. , Portable lightning detector. The method of claim 1, And at least two microphone inputs available for lightning detection, wherein lightning detection is performed in at least two different audible frequency bands. The method of claim 1, The lightning detection is performed as a detection combination on at least two frequency channels. The method of claim 1, And a detector capable of detecting two directions of lightning by using two orthogonally arranged antenna coils. A method of detecting lightning with a portable lightning detector with an antenna, amplifier front-end, A / D converter, and digital signal processor, The lightning detector is a mobile wireless device provided with an audio codec, the preamplifier of the codec is used to amplify the detected lightning signal, and the A / D converter of the codec is amplified. A digital audio processing unit of the codec is used for A / D conversion of the lightning signal, and is used for signal processing of lightning detection. The method of claim 9, Lightning detection front-end is connected in parallel with the microphone so that the microphone input of the audio codec is used jointly by lightning detection and other applications. Detection method. The method of claim 9, A microphone detection method, characterized in that a microphone input which is not used is used as a lightning detection front-end interface. The method of claim 9, Speech codec of the mobile wireless device is utilized for lightning detection, A / D converted lightning signal is processed in the voice codec path, and symbols detected and output by the voice codec are digital signal processing. Lightning detection method characterized in that it is analyzed in terms of lightning detection using signal processing (DSP). The method of claim 9, The amplification path of the audio codec is used in conjunction with the AM or FM radio receiver of the mobile radio for lightning detection, and these high frequency signals are down-converted to an audible frequency by a down-converter. Lightning detection method made with. The method of claim 9, There are at least two microphone inputs available for lightning detection, wherein the lightning detection is performed in at least two different audio frequency bands. The method of claim 9, Lightning detection is performed as a detection combination on at least two frequency channels. The method of claim 9, And a detector capable of detecting two directions of lightning by using two orthogonally arranged antenna coils. The method of claim 6, In addition, two coils may be used to achieve an omni-directional lightning detector, which may be implemented by using separate channels, or the signals from the two coils may be combined and analyzed as a signal. Removable lightning detector, characterized in that can be. The method of claim 14, In addition, two coils may be used to achieve an omni-directional lightning detector, which may be implemented by using separate channels, or the signals from the two coils may be combined and analyzed as a signal. Lightning detection method, characterized in that can be. The method of claim 1, And the wireless device comprises means for determining an orientation of the mobile wireless device. The method of claim 14, Utilizing the orientation of the detector device to improve the current consumption and measurement performance of the device. The method of claim 20, The orientation and / or movement of the detector is used to determine whether the detector device is stationary, and the measurement is performed only when the detector device is floating. The method of claim 14, The detected lightning information, including the event time, is stored in a memory to determine an expected lightning distance from the mobile device. The method of claim 14, And the mobile wireless device can store additional weather information received from a communication network in the storage device. The method of claim 14, A weather detection method, characterized in that weather information showing relative and true direction, distance, and intensity to a thunderstorm can be displayed on a display. The method of claim 1, A mobile lightning detector, characterized in that the front-end is integrated in a mobile wireless device. The method of claim 1, The front-end is a separate indicator device or is characterized in that it is integrated outside of the wireless device, for example as a so-called functional cover. The method of claim 1, And at least one indicator coil is an inductive charging coil or a coil used for any other purpose.

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