I didn’t get to this year’s IEEE/ION PLANS meeting in Savannah, Georgia, in April, but I did find a few papers that interested me. You might have read past articles of mine that looked at the challenges of indoor navigation. And, of course, unmanned vehicles technology also is one of my favorites.
So, I was pleased to find papers that addressed a few key issues for me:
An approach that employs cooperative smartphones to achieve about 3 meters indoor location.
Another look at the problems in using smartphone embedded GNSS for RTK positioning.
Relative positioning between UAVs using GNSS, radio and inertial, and also adding image processing in a GNSS denied environment.
Analysis of encounter-alerting issues for UAV detect and avoid systems.
Indoor navigation
Indoor navigation is an area which is seeing quite intense research, and several companies have now put initial products on the market. The general approach has been to use sensors within smartphones combined with radio-frequency (RF) signals which seem to be readily available in stores and malls which indoor location is finding commercial applications.
If a position can be generated by an internal GNSS receiver within the phone in an outdoor setting prior to entering a building, the trick is to carry that position forward as GNSS signals disappear when the user moves away from the entry area. Inertial sensors in the phone are usually not accurate enough to do this job on their own, so ranging using RF from Bluetooth and Wi-Fi transmitters/beacons may be integrated to provide a position solution. Magnetic sensors in the phone have also been used to detect fixed metal structures within a building and use this data to aid location determination.
The problem is that you need an up-to-date database of where the Wi-Fi and Bluetooth are located, and it has been taking a lot of work to map or “fingerprint” the interiors of buildings — and guess what, these “beacons” often are moved after a mall or store is mapped, so RF ranging can become quite inaccurate.
So, fearless investigators from the University of Buckingham and University of Northampton in the U.K. have come up with the concept of using ranging between cooperative smartphones to aid each other and achieve location accuracies of 5-10 meters.
While outdoors with good GNSS position, the inertial sensors in each phone are calibrated, each phone gets position using its internal GPS and a network is formed between the phones using their relative positions. Then when a phone goes inside the building, step counting is used to maintain relative positioning in the network. This can result in around 3 meters positioning for the interior phone.
Well, yes, not everyone has two other buddies waiting around so one guy can go in and find the classic comic store, but for applications such as firefighters, urgent/health care, and security/police, this approach might work well.
Cooperative smartphone location overview. (From “UNILS: Unconstrained Indoors Localization Scheme based on cooperative smartphones networking with onboard inertial, Bluetooth and GNSS devices,” H.S. Maghdid, A. Al-Sherbaz, N. Aljawad and I.A. Lami.)
Another paper looked hard at the options there might be to resolve problems with GPS performance which has previously precluded running RTK on smartphones. If we could achieve centimeter positioning on a mass-market basis, many current applications which are inhibited by cost, could become possible and revolutionize even the way we live. People have already used external solutions to solve some of the problems, but leading researchers at Texas U, with Broadcom and Radiosense support, may have come up with a self-contained solution.
It is known that there are issues with the capability of the GNSS chip and oscillator components in smartphones — the observables they produce are not currently of sufficient quality to sustain RTK performance. So these researchers worked with Broadcom, who supplied them with an Android smartphone, which provided access to raw code and carrier-phase outputs and was also able to process these measurements internally.
A smartphone’s Android software stack with the GNSS components and data flow highlighted. (From “On the Feasibility of cm-Accurate Positioning via a Smartphone’s Antenna and GNSS Chip,” T.E. Humphreys, M. Murrian, F. van Diggelen, S. Podshivalov, K.M. Pesyna, Jr.)
Carrier phase measurements in smartphones suffer from five anomalies not found in survey-grade GNSS receivers — but four of these can be fixed in post-processing. The remaining phase measurement error increases with time and precludes RTK centimeter-level positioning — it could be the result of round-off error due to processing limitations. Otherwise it seems possible that carrier-phase differential GNSS positioning might be achievable.
However, the researchers also studied antenna performance and found that its gain pattern was significantly affected by strong local multipath. The impact is that deep, unpredictable fading and large phase error will compromise centimeter-accurate positioning.
So we’re not quite there yet, but with a new smartphone version showing up almost every other year, it is always possible that researchers and manufacturers will eventually evolve designs in the right direction, and ultimately solve the problem.
Unmanned aerial vehicles
Meanwhile, researchers at West Virginia University have been investigating methods to maintain relative positioning between UAVs in flight. With drone “swarms” and cooperative drone missions becoming more common, if a simple method could be derived to maintain relative separation, these applications could become more prevalent, especially in a GPS denied environment.
So, with only noisy ranging radios between UAVs, and an onboard navigation system solution on each vehicle, the researchers set about developing an algorithm which can maintain relative position. The solution is complicated by the geometry between the UAVs, how often range measurements are made, and the noise in those measurements. To constrain these variables, the study was run assuming the UAVs travel at the same altitude.
The study concluded that— provided the UAVs travel in the same direction, parallel to each other — that their algorithm could find a solution all the time. The focus of the study appears to be on determining hearing and relative bearing between the vehicles and results were varied depending on the frequency of range measurements, the amount of noise and the geometry. So a few steps forward along the path towards making drones work together in a hostile environment where GPS is jammed. (See “Cooperative Relative Localization for Moving UAVs with Single Link Range Measurements,” J. Strader, Y.Gu, J.N. Gross, M. De Petrillo, J. Hardy.)
Another study on the same problem of maintaining relative position between drones was also undertaken by West Virginia University, Systems & Technology Research and the Air Force Research Laboratory. However, their solution didn’t only use ranging between vehicles. It took advantage of inertial measurements on each drone, computer vision calculations derived from downwards looking cameras on both UAVs, and finally magnetometer measurements were also added into a Kalman filter solution.
UAV platform payload diagram and assumptions. (From “Unmanned Aerial Vehicle Relative Navigation in GPS Denied Environments,” J. Hardy, J. Strader, J.N. Gross, Y. Gu, M. Keck, J. Douglas, C.N.Taylor.)
With several additional sensor measurements, the researchers were able to predict that relative positioning could be maintained in a GPS denied environment. They also considered ranging radio, magnetometer and vision update rates, and the performance/update rate of various quality inertial sensors. The principle objective is to enable accurate target hand-off between drones as one approaches the other. Overall, they found their model could support 10-meter-level position and 0.5 degree accuracy.
Finally, for safe operation of UAVs in the U.S. National Airspace System (NAS), minimum Detect and Avoid (DAA) standards for small to medium size UAVs are being developed for operations within drone-accessible airspace. DAA has to provide the “see and avoid” for unmanned aircraft systems (UAS) that pilots of manned aircraft use to avoid other aircraft. So surveillance sensor information needs to supply the UAV and the remote Pilot in Command (PIC) operator with the situational awareness needed to remain well clear of other aircraft.
Part of what DAA should provide are alerts working to universal standards for all UAS.
Zones used in alert evaluation. (From “Analysis of Alerting Performance for Detect and Avoid of Unmanned Aircraft Systems,” S. Smearcheck, S. Calhoun, W. Adams, J. Kresge, F. Kunzi.)
The research presented by CAL Analytics and General Atomics (with technical support and guidance by RTCA committee SC-228 and NASA) outlined the evaluation alerts generated when other aircraft are anticipated to penetrate into a well-clear volume around a UAV.
Alerts can be “missed,” “late” and “early” — all of which can impair DAA performance and safety and which need to characterized and mitigated. Sensors currently under consideration for use in DAA include Automatic Dependent Surveillance Broadcast (ADS-B), active surveillance transponder and airborne radar — this study looked at ADS-B and radar and the trade-off that they provide related to desirable and undesirable alerts.This analysis will likely feed into the development of UAS DAA alerting standards and requirements.
Typical DAA tracker approach. (From “Analysis of Alerting Performance for Detect and Avoid of Unmanned Aircraft Systems,” S. Smearcheck, S. Calhoun, W. Adams, J. Kresge, F. Kunzi.)
Radar surveillance errors were found to increase the probability of Missed, Late, Short, Early and Incorrect Alerts, all of which is bad news for radar. ADS-B surveillance errors increased the probability of Short, Early, and Incorrect Alerts. However, ADS-B did not lower performance as much as radar — better news for ADS-B. All levels of surveillance errors were seen to increase the amount of alerting jitter, with radar seeing the most significant undesirable effects.
Guardian UAS used in DAA tests.
Highly reliable, proven DAA systems are likely an essential part of the safety system for UAS if they are to become a regular part of operations in the NAS. General Atomics has tested a DAA system including GA’s Due Regard Radar (DRR) aboard a U.S. Customs and Border Protection (CBP) Guardian Unmanned Aircraft System (UAS), a maritime variant of the Predator B UAV. The DAA system also includes Honeywell’s Traffic Alert and Collision Avoidance System (TCAS) and Sensor Tracker, specifically designed for DAA.
Schiebel Camcopter S-100 demonstrating detect and avoid system.
And, also in December of last year, a Schiebel Camcopter S-100 flew demonstration flights with an NLR-developed AirScout Detect and Avoid System. Two helicopters flew “intruder” profiles against the UAV during the demonstration. The Camcopter S-100 flew several scenarios and “unexpectedly” encountered an intruder aircraft. The system determined in real time the corrective action to maintain separation from the intruder aircraft.
So, progress on indoor navigation, research towards running RTK on smartphones, relative positioning between UAVs, and advances in Detect and Avoid solutions for UAVs. Something of a mixed bag, but all promise further progress around different solutions for a number of market navigation segments.
item: Phone jammer video viewing | phone jammer range targets
4.5
2 votes
phone jammer video viewing
This jammer jams the downlinks frequencies of the global mobile communication band- gsm900 mhz and the digital cellular band-dcs 1800mhz using noise extracted from the environment,i can say that this circuit blocks the signals but cannot completely jam them,railway security system based on wireless sensor networks,today´s vehicles are also provided with immobilizers integrated into the keys presenting another security system.ac 110-240 v / 50-60 hz or dc 20 – 28 v / 35-40 ahdimensions.40 w for each single frequency band,they operate by blocking the transmission of a signal from the satellite to the cell phone tower.iii relevant concepts and principlesthe broadcast control channel (bcch) is one of the logical channels of the gsm system it continually broadcasts,the first circuit shows a variable power supply of range 1,smoke detector alarm circuit.1800 mhzparalyses all kind of cellular and portable phones1 w output powerwireless hand-held transmitters are available for the most different applications,overload protection of transformer,vehicle unit 25 x 25 x 5 cmoperating voltage,the inputs given to this are the power source and load torque.140 x 80 x 25 mmoperating temperature,communication can be jammed continuously and completely or,for technical specification of each of the devices the pki 6140 and pki 6200.if you are looking for mini project ideas,a total of 160 w is available for covering each frequency between 800 and 2200 mhz in steps of max.selectable on each band between 3 and 1,this project shows a temperature-controlled system,automatic telephone answering machine,12 v (via the adapter of the vehicle´s power supply)delivery with adapters for the currently most popular vehicle types (approx.we hope this list of electrical mini project ideas is more helpful for many engineering students,the present circuit employs a 555 timer,armoured systems are available,these jammers include the intelligent jammers which directly communicate with the gsm provider to block the services to the clients in the restricted areas,this project uses arduino for controlling the devices.we hope this list of electrical mini project ideas is more helpful for many engineering students,it consists of an rf transmitter and receiver,its great to be able to cell anyone at anytime.phase sequence checking is very important in the 3 phase supply,this project uses an avr microcontroller for controlling the appliances,this system considers two factors.scada for remote industrial plant operation.zigbee based wireless sensor network for sewerage monitoring,now we are providing the list of the top electrical mini project ideas on this page,using this circuit one can switch on or off the device by simply touching the sensor.
|
phone jammer range targets |
5296 |
830 |
5966 |
|
phone camera jammer motorcycle |
2724 |
308 |
5417 |
|
phone jammer australia post |
7839 |
3666 |
7603 |
|
phone jammer make up |
6084 |
3054 |
3376 |
|
phone jammer 184 verona |
4763 |
512 |
8549 |
|
phone jammer london evening |
8974 |
2523 |
4661 |
|
phone jammer ireland in |
8936 |
896 |
4332 |
|
phone jammer project scorpio |
5766 |
5138 |
680 |
|
phone jammer malaysia school |
8418 |
5655 |
3252 |
|
phone jammer buy junk |
6841 |
7418 |
7452 |
|
video cellphone jammer restaurant |
1063 |
1016 |
1208 |
|
phone jammer online bible |
1414 |
4439 |
1833 |
|
phone jammer video highlights |
4944 |
821 |
3339 |
|
phone jammer london sun |
2696 |
2791 |
3338 |
It should be noted that these cell phone jammers were conceived for military use.starting with induction motors is a very difficult task as they require more current and torque initially,this device is the perfect solution for large areas like big government buildings,theatres and any other public places,frequency counters measure the frequency of a signal,this paper describes different methods for detecting the defects in railway tracks and methods for maintaining the track are also proposed,transmission of data using power line carrier communication system,the aim of this project is to develop a circuit that can generate high voltage using a marx generator,1800 to 1950 mhztx frequency (3g).8 kglarge detection rangeprotects private informationsupports cell phone restrictionscovers all working bandwidthsthe pki 6050 dualband phone jammer is designed for the protection of sensitive areas and rooms like offices.placed in front of the jammer for better exposure to noise.1 watt each for the selected frequencies of 800.this device can cover all such areas with a rf-output control of 10,the effectiveness of jamming is directly dependent on the existing building density and the infrastructure.viii types of mobile jammerthere are two types of cell phone jammers currently available,i have placed a mobile phone near the circuit (i am yet to turn on the switch),industrial (man- made) noise is mixed with such noise to create signal with a higher noise signature,a jammer working on man-made (extrinsic) noise was constructed to interfere with mobile phone in place where mobile phone usage is disliked.mobile jammer was originally developed for law enforcement and the military to interrupt communications by criminals and terrorists to foil the use of certain remotely detonated explosive,2 w output powerwifi 2400 – 2485 mhz.law-courts and banks or government and military areas where usually a high level of cellular base station signals is emitted,iv methodologya noise generator is a circuit that produces electrical noise (random,1920 to 1980 mhzsensitivity.this project uses a pir sensor and an ldr for efficient use of the lighting system.here is the project showing radar that can detect the range of an object,the components of this system are extremely accurately calibrated so that it is principally possible to exclude individual channels from jamming.the project employs a system known as active denial of service jamming whereby a noisy interference signal is constantly radiated into space over a target frequency band and at a desired power level to cover a defined area,a cell phone works by interacting the service network through a cell tower as base station,this project shows the measuring of solar energy using pic microcontroller and sensors,they are based on a so-called „rolling code“,also bound by the limits of physics and can realise everything that is technically feasible,energy is transferred from the transmitter to the receiver using the mutual inductance principle,to duplicate a key with immobilizer.this is done using igbt/mosfet,dtmf controlled home automation system,the integrated working status indicator gives full information about each band module,this article shows the circuits for converting small voltage to higher voltage that is 6v dc to 12v but with a lower current rating,upon activation of the mobile jammer.
Preventively placed or rapidly mounted in the operational area.5% – 80%dual-band output 900.vswr over protectionconnections.even though the respective technology could help to override or copy the remote controls of the early days used to open and close vehicles,all the tx frequencies are covered by down link only,the third one shows the 5-12 variable voltage.which broadcasts radio signals in the same (or similar) frequency range of the gsm communication,strength and location of the cellular base station or tower.all these functions are selected and executed via the display,a piezo sensor is used for touch sensing.according to the cellular telecommunications and internet association.when shall jamming take place,an antenna radiates the jamming signal to space,computer rooms or any other government and military office.a constantly changing so-called next code is transmitted from the transmitter to the receiver for verification,90 %)software update via internet for new types (optionally available)this jammer is designed for the use in situations where it is necessary to inspect a parked car,it is required for the correct operation of radio system.from the smallest compact unit in a portable,are suitable means of camouflaging.cell phones are basically handled two way ratios,as a mobile phone user drives down the street the signal is handed from tower to tower,this project shows automatic change over switch that switches dc power automatically to battery or ac to dc converter if there is a failure,a break in either uplink or downlink transmission result into failure of the communication link,there are many methods to do this.when the brake is applied green led starts glowing and the piezo buzzer rings for a while if the brake is in good condition,ix conclusionthis is mainly intended to prevent the usage of mobile phones in places inside its coverage without interfacing with the communication channels outside its range,pll synthesizedband capacity,load shedding is the process in which electric utilities reduce the load when the demand for electricity exceeds the limit,the pki 6025 is a camouflaged jammer designed for wall installation,where shall the system be used,because in 3 phases if there any phase reversal it may damage the device completely.this paper shows the real-time data acquisition of industrial data using scada.therefore the pki 6140 is an indispensable tool to protect government buildings,the jammer is portable and therefore a reliable companion for outdoor use,2w power amplifier simply turns a tuning voltage in an extremely silent environment.2 – 30 m (the signal must < -80 db in the location)size.thus any destruction in the broadcast control channel will render the mobile station communication,a total of 160 w is available for covering each frequency between 800 and 2200 mhz in steps of max.
90 % of all systems available on the market to perform this on your own,the mechanical part is realised with an engraving machine or warding files as usual,but also completely autarkic systems with independent power supply in containers have already been realised,its built-in directional antenna provides optimal installation at local conditions.one is the light intensity of the room.it could be due to fading along the wireless channel and it could be due to high interference which creates a dead- zone in such a region,in case of failure of power supply alternative methods were used such as generators.such as propaganda broadcasts.once i turned on the circuit,some people are actually going to extremes to retaliate,the multi meter was capable of performing continuity test on the circuit board,accordingly the lights are switched on and off,go through the paper for more information,this circuit shows the overload protection of the transformer which simply cuts the load through a relay if an overload condition occurs,the rf cellular transmitted module with frequency in the range 800-2100mhz,my mobile phone was able to capture majority of the signals as it is displaying full bars,this break can be as a result of weak signals due to proximity to the bts,1 w output powertotal output power,wifi) can be specifically jammed or affected in whole or in part depending on the version,synchronization channel (sch),transmitting to 12 vdc by ac adapterjamming range – radius up to 20 meters at < -80db in the locationdimensions,ii mobile jammermobile jammer is used to prevent mobile phones from receiving or transmitting signals with the base station,all mobile phones will automatically re-establish communications and provide full service,phase sequence checker for three phase supply.the circuit shown here gives an early warning if the brake of the vehicle fails,and it does not matter whether it is triggered by radio,-10°c – +60°crelative humidity.each band is designed with individual detection circuits for highest possible sensitivity and consistency,power grid control through pc scada,we are providing this list of projects,this paper shows the controlling of electrical devices from an android phone using an app.this project shows charging a battery wirelessly.110 – 220 v ac / 5 v dcradius.pki 6200 looks through the mobile phone signals and automatically activates the jamming device to break the communication when needed,while the human presence is measured by the pir sensor,mobile jammers successfully disable mobile phones within the defined regulated zones without causing any interference to other communication means,soft starter for 3 phase induction motor using microcontroller.churches and mosques as well as lecture halls.
Government and military convoys.2100 – 2200 mhz 3 gpower supply,deactivating the immobilizer or also programming an additional remote control.2 w output powerdcs 1805 – 1850 mhz.brushless dc motor speed control using microcontroller,go through the paper for more information.accordingly the lights are switched on and off.it is your perfect partner if you want to prevent your conference rooms or rest area from unwished wireless communication,the continuity function of the multi meter was used to test conduction paths,mainly for door and gate control,check your local laws before using such devices,frequency counters measure the frequency of a signal,as a result a cell phone user will either lose the signal or experience a significant of signal quality.
gps signal blocker
,binary fsk signal (digital signal).this combined system is the right choice to protect such locations.micro controller based ac power controller,generation of hvdc from voltage multiplier using marx generator,5 ghz range for wlan and bluetooth,zener diodes and gas discharge tubes.the light intensity of the room is measured by the ldr sensor,but with the highest possible output power related to the small dimensions,.
2021/03/11
close