Gps signal jammers wholesale merchandise - wholesale gps signal jammer tours

Handling the Biases for Improved Triple-Frequency PPP Convergence By Denis Laurichesse Precise point positioning (PPP) can be considered a viable tool in the kitbag of GPS positioning techniques. One precision aspect of PPP is its use of carrier-phase measurements rather than just pseudoranges. But there is a catch. Often many epochs of measurements are needed for a position solution to converge to a sufficiently high accuracy. In this month’s column, we look at how using measurements from three satellite frequencies rather than just two can help. INNOVATION INSIGHTS by Richard Langley PPP? WHAT’S THAT? This acronym stands for precise point positioning and, although the technique is still in development, it has evolved to a stage where it can be considered another viable tool in the kitbag of GPS positioning techniques. It is now supported by a number of receiver manufacturers and several free online PPP processing services. You might think, looking at the name, that there’s nothing particularly special about it. After all, doesn’t any kind of positioning with GPS give you a precise point position including that from a handheld receiver or a satnav device? They key word here is precise. The use of the word precise, in the context of GPS positioning, usually means getting positional information with precision and accuracy better than that afforded by the use of L1 C/A-code pseudorange measurements and the data provided in the broadcast navigation messages from the satellites. A typically small improvement in precision and accuracy can be had by using pseudoranges determined from the L2 frequency in addition to L1. This permits the real-time correction for the perturbing effect of the ionosphere. Such an improvement in positioning is embodied in the distinction between the two official GPS levels of service: the Standard Positioning Service provided through the L1 C/A-code and the Precise Positioning Service provided for “authorized” users, which requires the use of the encrypted P-code on both the L1 and L2 frequencies. Civil GPS users will have access to a similar level of service once a sufficient number of satellites transmitting the L2 Civil (L2C) code are in orbit. However, this capability will only provide meter-level accuracy. The PPP technique can do much better than this. It can do so thanks to two additional precision aspects of the technique. The first is the use of more precise (and, again, accurate) descriptions of the orbits of the satellites and the behavior of their atomic clocks than those included in the navigation messages. Such data is provided, for example, by the International GNSS Service (IGS) through its global tracking network and analysis centers. These so-called precise products are typically used to process receiver data after collection in a post-processing mode, although real-time correction streams are now being provided by the IGS and some commercial entities. Now, it’s true that a user can get high precision and accuracy in GPS positioning using the differential technique where data from one or more base or reference stations is combined with data from the user receiver. However, by using precise products and a very thorough model of the GPS observables, the PPP technique does away with the requirement for a directly accessed base station. The other precision aspect of PPP is its use of carrier-phase measurements rather than just pseudoranges. Carrier-phase measurements have a precision on the order of two magnitudes (a factor of 100) better than that of pseudoranges. But there is a catch to the use of carrier-phase measurements: they are ambiguous by an integer multiple of one cycle. Processing algorithms must resolve the value of this ambiguity and ideally fix it at its correct integer value. Unfortunately, it is difficult to do this instantaneously, and often many epochs of measurements are needed for a position solution to converge to a sufficiently high accuracy, say better than 10 centimeters. Researchers are actively working on reducing the convergence time, and in this month’s column, we look at how using measurements from three satellite frequencies rather than just two can help. “Innovation” is a regular feature that discusses advances in GPS technology and its applications as well as the fundamentals of GPS positioning. The column is coordinated by Richard Langley of the Department of Geodesy and Geomatics Engineering, University of New Brunswick. He welcomes comments and topic ideas. To contact him, see the “Contributing Editors” section on page 6. While carrier-phase measurements typically have very low noise compared to pseudorange (code) measurements, they have an inherent integer cycle ambiguity: the carrier phase, interpreted as a range measurement, is ambiguous by any number of cycles. However, integer ambiguity fixing is now routinely applied to undifferenced GPS carrier-phase measurements to achieve precise positioning. Some implementations are even available in real time. This so-called precise point positioning (PPP) technique permits ambiguity resolution at the centimeter level. With the new modernized satellites’ capabilities, performing PPP with triple-frequency measurements will be possible and, therefore, the current dual-frequency formulation will not be applicable. There is also a need for a generalized formulation of phase biases for Radio Technical Commission for Maritime Services (RTCM) State Space Representation (SSR) needs. In this RTCM framework, the definition of a standard is important to allow interoperability between the two components of a positioning system: the network side and the user side. Classical Formulation In this section, we review the formulation of the observation equations. We will use the following constants in the equations: where f1 and f2 are the two primary frequencies transmitted by all GPS satellites and c is the vacuum speed of light. For the GPS L1 and L2 bands, f1 = 154f0 and f2 = 120f0, where f0 = 10.23 MHz. The pseudorange (or code) measurements, P1 and P2, are expressed in meters, while phase measurements, L1 and L2, are expressed in cycles. In the following, we use the word “clock” to mean a time offset between a receiver or satellite clock and GPS System Time as determined from either code or phase measurements on different frequencies or some combination of them. The code and phase measurements are modeled as: (1) where: D1 and D2 are the geometrical propagation distances between the emitter and receiver antenna phase centers at f1 and f2 including troposphere elongation, relativistic effects and so on. W is the contribution of the wind-up effect (in cycles). e is the code ionosphere elongation in meters at f1. This elongation varies with the inverse of the square of the carrier frequency and is applied with the opposite sign for phase. Δh = hi – hj is the difference between receiver i and emitter j ionosphere-free phase clocks. Δhp is the corresponding term for code clocks. Δτ = τi – τj is the difference between receiver i and emitter j offsets between the phase clocks at f1 and the ionosphere-free phase clocks. By construction, the corresponding quantity at f2 is γΔτ. Similarly, the corresponding quantity for the code is Δτp (time group delay). N1 and N2 are the two carrier-phase ambiguities. By definition, these ambiguities are integers. Unambiguous phase measurements are therefore L1 + N1 and L2 + N2. Equations (1) take into account all the biases related to delays and clock offsets. The four independent parameters, Δh, Δτ, Δhp, and Δτp, are equivalent to the definition of one clock per observable. However, our choice of parameters emphasizes the specific nature of the problem by identifying reference clocks for code and phase (Δhp and Δh) and the corresponding hardware offsets (Δτp and Δτ). These offsets are assumed to vary slowly with time, with limited amplitudes. The measured widelane ambiguity, , (also called the Melbourne-Wübbena widelane) can be written as: (2) where Nw is the integer widelane ambiguity, μ j is the constant widelane delay for satellite j and μi is the widelane delay for receiver i (which is fairly stable for good quality geodetic receivers). The symbol means that all quantities have been averaged over a satellite pass. Integer widelane ambiguities are then easily identified from averaged measured widelanes corrected for satellite widelane delays. Once integer widelane ambiguities are known, the ionosphere-free phase combination can be expressed as (3) where is the ionosphere-free phase combination computed using the known Nw ambiguity, Dc is the propagation distance, hi is the receiver clock and h j is the satellite clock. N1 is the remaining ambiguity associated to the ionosphere-free wavelength λc (10.7 centimeters). The complete problem is thus transformed into a single-frequency problem with wavelength λc and without any ionosphere contribution. Many algorithms can be used to solve Equation (3) using data from a network of stations. If Dc is known with sufficient accuracy (typically a few centimeters, which can be achieved using a good floating-point or real-valued ambiguity solution), it is possible to simultaneously solve for N1 , hi and h j. The properties of such a solution have been studied in detail. A very interesting property of the h j satellite clocks is, in particular, the capability to directly fix (to the correct integer value) the N1 values of a receiver that was not part of the initial network. The majority of the precise-point-positioning ambiguity-resolution (PPP-AR) implementations are based on the identification and use of the two quantities μ j and h j. These quantities may be called widelane biases and integer phase clocks, a decoupled clock model or uncalibrated phase delays, but they are all of the same nature. A Real-Time PPP-AR Implementation A PPP-AR technique was successfully implemented by the Centre National d’Etudes Spatiales (CNES) in real time in the so-called PPP-Wizard demonstrator in 2010 and has been subsequently improved. In this demonstrator and in the framework of the International GNSS Service (IGS) Real-Time Service (RTS) and the RTCM, the GPS and GLONASS constellation orbits and clocks are computed. Additional biases for GPS ambiguity resolution are computed and broadcast to the user. The demonstrator also provides an open-source implementation of the method on the user side, for test purposes. Centimeter-level positioning accuracy in real time is obtained on a routine basis. Limitations of the Bias Formulations. The current formulation works but it has several drawbacks: The chosen representation is dependent on the implemented method. Even if the nature of the biases is the same, their representation may be different according to the underlying methods, and this makes it difficult for a standardization of the bias messages. The user side must implement the same method as the one used on the network side. Otherwise, the user side would have to convert the quantities from one method to another, leading to potential bugs or misinterpretations. It is limited to the dual-frequency case. There are only two quantities to be computed in the dual-frequency case ( and ), but in the triple-frequency case, there are many more possible combinations. For example, one can have (this is a non-exhaustive list) , , ,, , , where the indices refer to different pairs of frequencies, and other ionosphere-free combinations such as phase widelane-only or even phase ionosphere-free and geometry-free combinations are possible. New RTCM SSR Model The new model, as proposed by the RTCM Special Committee 104 SSR working group for phase bias messages is based on the idea that the phase bias is inherent to each frequency. Thus, instead of making specific combinations, one phase bias per phase observable is identified and broadcast. It is noted that this convention was adopted a long time ago for code biases. Indeed, in the RTCM framework, and unlike the standard differential code bias (DCB) convention where code biases are undifferenced but combined, the RTCM SSR code biases are defined as undifferenced and uncombined. The general model for uncombined code and phase biases is therefore: (4) Time group delays, τ, and phase clocks, h, in Equation (1) are replaced by code and phase biases (ΔbP and ΔbL respectively). RTCM SSR code and phase biases correspond to the satellite part of these biases. The prime notation denotes the “unbiasing” process of the measurements. Here, the clock definition is crucial. As the biases are uncombined, they are referenced to the clocks. The convention chosen for the standard is natural: it is the same as the one used by IGS, that is, ΔhP in our notation. This new model can be extended to the triple-frequency case very easily, as it does not involve explicit dual-frequency combinations: (5) This new model simplifies the concept of phase biases for ambiguity resolution. This representation is very attractive because no assumption is made on the method used to identify phase biases on the network side. All the implementations are valid if they respect this proposed model. It also allows convenient interoperability if the network and user sides implement different ambiguity resolution methods. TABLE 1 summarizes the different messages used for PPP-AR in the context of RTCM SSR: TABLE 1. RTCM SSR messages for PPP-AR. Bias Estimation in the Dual-Frequency Case. The new phase biases identification in the dual-frequency case is straightforward. There are two biases (, ) to be estimated using two combinations (µ and h). The problem to be solved is described in FIGURE 1. FIGURE 1. Phase biases estimation in the dual-frequency case. It can be solved very easily on the network side by means of a 2 × 2 matrix inversion: (6) with Note: All the quantities denote the satellite part of the Δ operator defined above. Bias Estimation in the Triple-Frequency Case. The triple-frequency bias identification is tricky due to the need, using only three biases, to keep the integer nature of phase ambiguities on all viable ionosphere-free combinations, and in particular combinations that were not used in the identification process. At this level, one cannot make assumptions on what kind of combinations will be employed by a user. The problem to be solved is described in FIGURE 2. FIGURE 2. Phase biases estimation in the triple-frequency case. As an example, a naïve solution would be to identify the extra-widelane phase biases,, using the dual-frequency widelane approach, and then identify thebias. Given the large wavelength of the extra-widelane combination, such identification would be very easy. However, the corresponding bias would be only helpful for extra-widelane ambiguity identification, and its noise would prevent its use for widelane 15 (L1/L5) ambiguity resolution or other useful combinations available in the triple-frequency context. Each independent phase bias can be directly estimated in a filter; however, in order to keep ascending compatibility with the dual-frequency case during the deployment phase of the new modernized satellites, we have chosen to stay in the old framework, that is, to work with combinations of biases. The resolution method is the following: The widelane biases, that is, the identification of all the bLi – bLj quantities, are solved. For this computation and in order to have an accurate estimate of these biases, the two MW-widelane biases µ12 and µ15 are used coupled to an additional phase bias, which is given by the triple-frequency ionosphere-free phase combination with the integer widelane ambiguities already fixed. This last combination using only phase measurements is much more accurate than MW-widelanes. The system to be solved is redundant and the noise of the different equations has to be chosen carefully. The remaining bias (bLi ) is estimated using the traditional ionosphere-free phase combination of L1 and L2. This computation has been implemented in the CNES real-time analysis center software, and since September 15, 2014, CNES broadcasts phase biases compatible with this triple-frequency concept on the IGS CLK93 real-time data stream. Real Data Analysis To prove the validity of the concept, at CNES, we compute several ambiguity combinations using real data. The process is the following: Look for good receiver locations having a large number of GPS Block IIF satellites (transmitting the L5 signal) in view for a period of time exceeding 30 minutes, and choose among them, one participating in the IGS Multi-GNSS (MGEX) experiment. The station CPVG (Cape Verde) in the Reseau GNSS pour l’IGS et la Navigation (REGINA) network was chosen for the time span on September 28, 2014, between 19 and 20 hours UTC. During this period, four Block IIF satellites were visible simultaneously (PRNs 1, 6, 9, 30) for a total of 14 GPS satellites in view. Record a compatible phase-bias stream. The CLK93 stream is recorded during the time span of the experiment. Perform a PPP solution using the measurements, CLK93 corrections and biases to estimate the propagation distance, the troposphere delay and the receiver clock and phase ambiguity estimates according to Equation (5). For different ambiguity estimates, compute and plot the obtained residuals. We present in the following graphs various ambiguity residuals for the four Block IIF satellites in view. The values of each ambiguity are offset by an integer value for clarity purposes. Melbourne-Wübbena Extra-Widelane. FIGURE 3 represents the MW extra-widelane (between frequencies L2 and L5) ambiguity estimation using our process. The MW extra-widelane ambiguity has a wavelength of 5.86 meters. The noise of the combination expressed in cycles is very low, and the integer nature of ambiguities in this combination is clearly visible. FIGURE 3. Ambiguity residuals for the extra-widelane 5-2 combination. Melbourne-Wübbena Widelanes. FIGURE 4 represents the MW-widelanes (the regular 1-2 and 1-5 combinations). Here again, the integer nature of the four ambiguities is clearly visible. FIGURE 4. Ambiguity residuals for widelane combinations; top: 1-2 widelane, bottom: 1-5 widelane. Widelane-Only Ionosphere-Free Phase. In the triple-frequency context, there is a possibility of forming an ionosphere-free combination of the three phase observables. This combination has an important noise amplification factor (>20), but would allow us to perform decimeter-accuracy PPP using only the solved widelane integer ambiguities and if the corresponding phase biases are accurate. In addition, it can be shown that the wavelength of the widelane ambiguity when the extra-widelane ambiguity is solved is about 3.4 meters. It means that the remaining widelane using this combination can be solved if the position is accurate enough (a few tens of centimeters) and the extra-widelane is known. FIGURE 5 shows such a case, that is, the residuals of the widelane ambiguity using this combination and assuming that the extra-widelane is already solved for. FIGURE 5. Ambiguity residuals for widelane-only 1-2-5 ionosphere free combinations. Such a case where the solution is the most biased is shown (the dark blue curve). This behavior is mainly due to the difficulty in estimating the phase biases on this combination accurately using only a few Block IIF satellites. We hope that in the future the increasing number of modernized satellites will help such bias estimation. N1 Ionosphere-Free Phase. FIGURES 6 to 8 show the three possible ambiguity estimates using the ionosphere-free phase combination with two measurements (we assume that the corresponding widelane has already been solved). In each case, the computed biases allow us to easily retrieve the integer nature of the N1 ambiguity. FIGURE 6. Ambiguity residuals for the N1 combination using a fixed 1-2 widelane. FIGURE 7. Ambiguity residuals for the N1 combination using a fixed 1-5 widelane. FIGURE 8. Ambiguity residuals for the N1 combination using a fixed 2-5 widelane. Application to Triple-Frequency PPP The results presented above show that the integer ambiguity nature of phase measurements is conserved for various useful observable combinations and prove the validity of the model. Another experiment has been carried out to estimate the impact of ambiguity convergence in the triple-frequency context. For that, in order to maximize the observability of the GPS Block IIF constellation and thus the accuracy of the biases, a network of ten stations across Europe has been chosen for the phase biases computation (see FIGURE 9). The station REDU (in green) was the test station to be positioned. The test occurred on January 10, 2015, around 11:00 UTC. At that time, four Block IIF satellites were visible simultaneously (PRNs 1, 3, 6, 9) for a total of 10 satellites in view. FIGURE 9. Network used for the triple-frequency PPP study. The PPP-Wizard open source client was used to perform PPP in real time. The advantage of this implementation is that it directly follows the uncombined observable formulation described in Equations (5). The strategy for ambiguity resolution is a simple bootstrap approach. Convergence of the Widelane-Only Solution. In this test, a PPP solution was performed, but only the fixing of the widelane ambiguities was implemented. As noted in the previous section, the wavelength of the widelane ambiguity when the extra-widelane ambiguity is solved is about 3.4 meters, so it is expected that all the widelanes can be fixed in a very short time. Despite the amplification factor of about 20 of the equivalent unambiguous phase combination, we expect to obtain an accuracy of about 10 centimeters with such a solution. FIGURE 10 shows the convergence time of several PPP runs in this context (16 different runs of five minutes are superimposed), in terms of horizontal position error. FIGURE 10. Widelane-only triple-frequency PPP convergence (horizontal position error). The extra-widelanes are fixed instantaneously; the remaining widelanes are fixed in about two minutes on average to be below 30 centimeters (this is represented by the different sharp reductions of the errors). This new configuration, available in the triple-frequency context, is very interesting as it provides an intermediate class of accuracy, which converges very quickly and which is suitable for applications that do not demand centimeter accuracy. Another interesting aspect of this combination is the gap-bridging feature. In PPP, gap-bridging is the functionality that allows us to recover the integer nature of the ambiguities after a loss of the receiver measurements over a short period of time (typically a pass through a tunnel or under a bridge). This is done usually by means of the estimation of a geometry-free combination (ionosphere delay estimation) during the gap. Realistic maximum gap duration in the dual-frequency case is about one minute. In the triple-frequency case, the wavelength of the geometry-free combination involving the widelane (if the extra-widelane is fixed) is 1.98 meters. With such a large wavelength, the gaps are much easier to fill, and we can safely extend the gap duration to several minutes. In addition, the widelane combinations are wind-up independent, so there is no need to monitor a possible rotation of the antenna during the gap, as in the dual-frequency case. Overall Convergence (All Ambiguities). Another PPP convergence test has been carried out with all ambiguities fixing activated (four different runs of 15 minutes are superimposed). Results are shown in FIGURE 11. FIGURE 11. All ambiguities triple-frequency PPP convergence (horizontal position error). The centimeter accuracy is obtained in this configuration within eight minutes, which is a significant improvement in comparison to the dual-frequency case. Further improvement of this convergence time is expected with an increase in the number of Block IIF satellites and, subsequently, GPS IIIA satellites. Convergence Time Comparison Between the Dual- and Triple-Frequency Contexts. Thanks to these new results, a realistic picture for PPP convergence in the dual- and triple-frequency contexts can be drawn. To do so, polynomial functions have been fitted over the data points obtained in the previous studies. Two data sets were used: Standard dual-frequency convergence (GPS only, 10 satellites in view). Triple-frequency convergence (GPS only, 10 satellites in view, four Block IIF satellites). FIGURE 12 represents the comparison between the two polynomials (horizontal error). FIGURE 12. Realistic PPP convergence comparison between dual- and triple-frequency contexts (horizontal position error). Conclusion The new phase-bias concept proposed for RTCM SSR has been successfully implemented in the CNES IGS real-time analysis center. This new concept represents the phase biases in an uncombined form, unlike the previous formulations. It has the advantage of the unification of the different proposed methods for ambiguity resolution, and it prepares us for the future; for example, for a widely available triple-frequency scenario. The validity of this concept has been shown; that is, the integer ambiguity nature of phase measurements is conserved for various useful observable combinations. In addition, we have also shown that the triple-frequency context has a significant impact on ambiguity convergence time. The overall convergence time is drastically reduced (to some minutes instead of some tens of minutes) and there is an intermediate combination (widelane-only) that has some interesting properties in terms of convergence time, accuracy and gap-bridging for non-demanding centimeter-level applications. Acknowledgments The contributions of colleagues contributing to the IGS services are gratefully acknowledged. Geo++ is thanked for useful discussions on the standardization of phase bias representation. DENIS LAURICHESSE received his engineering degree and a Diplôme d’études appliquées (an advanced study diploma) from the Institut National des Sciences Appliquées in Toulouse, France, in 1988. He has worked in the Spaceflight Dynamics Department of the Centre National d’Etudes Spatiales (CNES, the French Space Agency) in Toulouse since 1992, responsible for the development of the onboard GNSS Diogene navigator. He was involved in the performance assessment of the EGNOS and Galileo systems and is now in charge of the CNES International GNSS Service real-time analysis center. He specializes in navigation, precise satellite orbit determination and GNNS-based systems. He was the recipient of The Institute of Navigation Burka Award in 2009 for his work on phase ambiguity resolution. Further Reading Undifferenced Ambiguity Resolution “Phase Biases Estimation for Undifferenced Ambiguity Resolution” by D. Laurichesse, presented at PPP-RTK & Open Standards Symposium, Frankfurt, Germany, March 12–13, 2012. “Undifferenced GPS Ambiguity Resolution Using the Decoupled Clock Model and Ambiguity Datum Fixing” by P. Collins, S. Bisnath, F. Lahaye, and P. Héroux in Navigation, Journal of The Institute of Navigation, Vol. 57, No. 2, Summer 2010, pp. 123–135, doi: 10.1002/j.2161-4296.2010.tb01772.x. “Integer Ambiguity Resolution on Undifferenced GPS Phase Measurements and Its Application to PPP and Satellite Precise Orbit Determination” by D. Laurichesse, F. Mercier, J.-P. Berthias, P. Broca, and L. Cerri in Navigation, Journal of The Institute of Navigation, Vol. 56, No. 2, Summer 2009, pp. 135–149, doi: 0.1002/j.2161-4296.2009.tb01750.x. “Resolution of GPS Carrier-Phase Ambiguities in Precise Point Positioning (PPP) with Daily Observations” by M. Ge, G. Gendt, M. Rothacher, C. Shi, and J. Liu in Journal of Geodesy, Vol. 82, No. 7, pp. 389–399, doi: 10.1007/s00190-007-0187-4. Erratum: 10.1007/s00190-007-0208-3. Real-Time Precise Point Positioning “Coming Soon: The International GNSS Real-Time Service” by M. Caissy, L. Agrotis, G. Weber, M. Hernandez-Pajares, and U. Hugentobler in GPS World, Vol. 23, No. 6, June 2012, pp. 52–58. “The CNES Real-time PPP with Undifferenced Integer Ambiguity Resolution Demonstrator” by D. Laurichesse in Proceedings of ION GNSS 2011, the 24th International Technical Meeting of The Satellite Division of the Institute of Navigation, Portland, Ore, September 20–23, 2011, pp. 654–662. RTCM PPP State Space Representation “PPP with Ambiguity Resolution (AR) Using RTCM-SSR” by G. Wübbena, M. Schmitz, and A. Bagge, presented at IGS Workshop, Pasadena, Calif., June 23–27, 2014. “The RTCM Multiple Signal Messages: A New Step in GNSS Data Standardization” by A. Boriskin, D. Kozlov, and G. Zyryanov in Proceedings of ION GNSS 2012, the 25th International Technical Meeting of The Satellite Division of the Institute of Navigation, Nashville, Tenn., September 17–21, 2012, pp. 2947-2955. “RTCM State Space Representation (SSR): Overall Concepts Towards PPP-RTK” by G. Wübbena, presented at PPP-RTK & Open Standards Symposium, Frankfurt, Germany, March 12–13, 2012. Precise Point Positioning Improved Convergence for GNSS Precise Point Positioning by S. Banville, Ph.D. dissertation, Department of Geodesy and Geomatics Engineering, Technical Report No. 294, University of New Brunswick, Fredericton, New Brunswick, Canada. Recipient of The Institute of Navigation 2014 Bradford W. Parkinson Award. “Precise Point Positioning: A Powerful Technique with a Promising Future” by S.B. Bisnath and Y. Gao in GPS World, Vol. 20, No. 4, April 2009, pp. 43–50.

gps signal jammers wholesale merchandise

How a cell phone signal booster works,upon activating mobile jammers,cyber acoustics ka12d120050035u ac adapter 12vdc 500ma +(-) 2x5.,chd ud4120060060g ac adapter 6vdc 600ma 14w power supply,fujitsu fpcbc06 ac adapter 16v dc 35w used 2.5 x 5.4 x 12.1 mm t,toshiba pa3237u-1aca ac adapter 15v dc 8a used 4pin female ite,utstarcom psc11a-050 ac adapter +5vdc 2a used -(+) 1.5x4mm cru66.laptopsinternational lse0202c1990 ac adapter 19vdc 4.74a used.btc adp-305 a1 ac adapter 5vdc 6a power supply,and lets you review your prescription history.deer ad1809c ac adapter 9vdc 2.25a 18w used -(+) 2x5.5mm power s,asa aps-35a ac adapter 35v 0.6a 21w power supply with regular ci,motorola ssw-0828 ac adapter 6.25v 350ma cell phone chargercon.jobmate battery charger 12v used 54-2778-0 for rechargeable bat.symbol pa-303-01 ac adapter dc 12v 200ma used charging dock for,aok ak02g-1200100u ac adapter 12vdc 1a used 2 x 5.5 x 10mm,merkury f550 1 hour sony f550 rapid lithium ion battery charger,aw17-3r3-u ac adapter 3.3vdc 5a used 1.8x5.5x9.7mm straight.both outdoors and in car-park buildings.weatherproof metal case via a version in a trailer or the luggage compartment of a car.altec lansing s012bu0500250 ac adapter 5vdc 2500ma -(+) 2x5.5mm.gbc 1152560 ac adapter 16vac 1.25a used 2.5x5.5x12mm round barre,this project shows automatic change over switch that switches dc power automatically to battery or ac to dc converter if there is a failure,the inputs given to this are the power source and load torque,dve dsa-0051-03 fus ac adapter 5vdc 0.5a mini usb charger.aciworld 48-7.5-1200d ac adapter 7.5v dc 1200ma power supply.li shin lse9802a2060 ac adapter 20vdc 3a 60w used -(+) 2.1x5.5mm,ut starcom adp-5fh b ac adapter 5vdc 1a used usb phone charger p,this project shows the measuring of solar energy using pic microcontroller and sensors.the device looks like a loudspeaker so that it can be installed unobtrusively,here is a list of top electrical mini-projects,sony ac-v55 ac adapter 7.5v 10v dc 1.6a 1.3a 26w power supply.tedsyn dsa-60w-20 1 ac adapter 24vdc 2.5a -(+)- 2.x 5.5mm straig,cell phone jammers have both benign and malicious uses.it can not only cut off all 5g 3g 4g mobile phone signals,its called denial-of-service attack.hp ppp017h ac adapter 18.5vdc 6.5a 120w used -(+) 2.5x5.5mm stra.dual group au-13509 ac adapter 9v 1.5a used 2x5.5x12mm switching.dpx351314 ac adapter 6vdc 300ma used -(+)- 2.4 x 5.3 x 10 mm str.motorola ntn9150a ac adapter 4.2vdc 0.4a 6w charger power supply.failure to comply with these rules may result in,remington ms3-1000c ac dc adapter 9.5v 1.5w power supply,usually by creating some form of interference at the same frequency ranges that cell phones use.ibm 12j1441 ac adapter 16vdc 2.2a class 2 power supply 12j1442,at&t tp-m ac adapter 9vac 780ma used ~(~) 2x5.5x11mm round barre,a mobile jammer circuit or a cell phone jammer circuit is an instrument or device that can prevent the reception of signals by mobile phones.hipro hp-a0301r3 ac adapter 19vdc 1.58a -(+) 1.5x5.5mm used roun,thomson 5-2608 ac adapter 9vdc 500ma used -(+) 2x5.5x9mm round b.

Dell pa-12 ac adapter 19.5vdc 3.34a power supply for latitude in,preventively placed or rapidly mounted in the operational area,liteon pa-1900-24 ac adapter 19v 4.74a acer gateway laptop power.compaq pe2004 ac adapter 15v 2.6a used 2.1 x 5 x 11 mm 90 degree,mastercraft sa41-6a battery carger 7.2vdc used -(+) power supply,ibm pa-1121-071 ac adapter 16vdc 7.5a used 4-pin female 02k7086.this paper shows the controlling of electrical devices from an android phone using an app,apple macintosh m4402 24vdc 1.875a 3.5mm 45w ite power supply,sony adp-8ar a ac adapter 5vdc 1500ma used ite power supply,tc-60a ac adapter 9vdc 1.3a -(+) 1.3x3.5mm 100-240vac used direc.conswise kss06-0601000d ac adapter 6v dc 1000ma used.preventing them from receiving signals and …,control electrical devices from your android phone,audiovox cnr-9100 ac adapter 5vdc 750ma power supply.you can get full command list from us,netgear sal018f1na ac adapter 12vdc 1.5a used -(+) 2x5.5x9mm rou.apd ne-17b512 ac adapter 5v 1.2a 12v 1a power supply i.t.e,dsa-0151d-12 ac adapter 12vdc 1.5a -(+)- 2x5.5mm 100-240vac powe.motorola psm4716a ac power supply dc 4.4v 1.5a phone charger spn,computer wise dv-1280-3 ac adapter 12v dc 1000ma class 2 transfo.the best cell phone signal booster to get for most people is the weboost home 4g cell phone signal booster (view on ebay ).hp compaq adp-65hb b ac adapter 18.5vdc 3.5a -(+) 1.7x4.8mm used,replacement ppp009l ac adapter 18.5vdc 3.5a 1.7x4.8mm -(+) power.fujitsu adp-80nb a ac adapter 19vdc 4.22a used -(+) 2.5x5.5mm c.griffin p2275 charger 5vdc 2.1a from 12vdc new dual usb car adap.5810703 (ap2919) ac adapter 5vdc 1.5a -(+) used 1.5x4x10 mm 90°,this paper describes the simulation model of a three-phase induction motor using matlab simulink,go through the paper for more information,the latest 5g signal jammers are available in the jammer -buy store.people also like using jammers because they give an “out of service” message instead of a “phone is off” message,polycomfsp019-1ad205a ac adapter 19v 1a used -(+) 3 x 5.5mm 24.to avoid out-band jamming generation,the frequency blocked is somewhere between 800mhz and1900mhz.ambico ue-4112600d ac dc adapter 12v 7.2va power supply.medtronic pice-34a ac adapter 6v dc 35ma 1.1w battery chargerc,when you choose to customize a wifi jammer.hp 0950-2852 class 2 battery charger nicd nimh usa canada,toshiba pa-1900-03 ac adapter used -(+) 19vdc 4.74a 2.5x5.5mm la,the third one shows the 5-12 variable voltage.long range jammer free devices.dell fa90ps0-00 ac adapter 19.5vdc 4.62a 90w used 1x5x7.5xmm -(+,canon cb-2lt battery charger 8.4v 0.5a for canon nb-2lh recharge.compaq adp-60bb ac adapter 19vdc 3.16a used 2.5x5.5mm -(+)- 100-,deer ad1605cf ac adapter 5.5vdc 2.3a 1.3mm power supply.kingshen mobile network jammer 16 bands highp power 38w adjustable desktop jammer ₹29,insignia e-awb135-090a ac adapter 9v 1.5a switching power supply.“1” is added to the fault counter (red badge) on the hub icon in the ajax app,the integrated working status indicator gives full information about each band module.

Delta electronics adp-60cb ac dc adapter 19v 3.16a power supply,yhsafc0502000w1us ac adapter 5vdc 2a used -(+) 1.5x4x9mm round b.aci communications lh-1250-500 ac adapter -(+) 12.5vdc 500ma use.here is the project showing radar that can detect the range of an object,find here mobile phone jammer.ac adapter used car charger tm & dc comics s10.averatec sadp-65kb b ac adapter19vdc 3.42a used 2.5x5.4x11.2mm,2100-2200 mhzparalyses all types of cellular phonesfor mobile and covert useour pki 6120 cellular phone jammer represents an excellent and powerful jamming solution for larger locations.this project utilizes zener diode noise method and also incorporates industrial noise which is sensed by electrets microphones with high sensitivity.50/60 hz transmitting to 12 v dcoperating time,lenovo 92p1160 ac adapter 20v 3.25a power supply 65w for z60.motorola spn4569e ac adapter 4.4-6.5vdc 2.2-1.7a used 91-57539,nokia ac-15x ac adapter cell phone charger 5.0v 800ma europe 8gb,sony ac-e351 ac adapter 3v 300ma power supply with sony bca-35e.gamestop 5v wii remote conteroller charging dock,eng 3a-122du12 ac adapter 12vdc 1a -(+) 2x5.5mm used power suppl.wifi network jammer using kali linux introduction websploit is an open source project which is used to scan and analysis remote system in order to find various type of vulnerabilites,this project creates a dead-zone by utilizing noise signals and transmitting them so to interfere with the wireless channel at a level that cannot be compensated by the cellular technology,the present circuit employs a 555 timer,ps120v15-d ac adapter 12vdc 1.25a used2x5.5mm -(+) straight ro.canon k30327 ac adapter 32vdc 24vdc triple voltage power supply,opti pa-225 ac adapter +5vdc +12vdc 4pins switching power supply.nikon eh-52 ac adapter 8.4vdc -(+) 10.9w for coolpix digital cam,d-link cg2412-p ac adapter 12vdc 2a -(+) used 1.2x3.75mm europe,makita dc9100 fast battery chrgar 9.6vdc 1.5a used drill machine,novus dc-401 ac adapter 4.5vdc 100ma used 2.5 x 5.5 x 9.5mm,sii psa-30u-050 ac adapter 5v 4a slp2000 sii smart label printer.viasys healthcare 18274-001 ac adapter 17.2vdc 1.5a -(+) 2.5x5.5,replacement vsk-0725 ac adapter 7.9vdc 1.4a power supply for pan,ilan elec f1700c ac adapter 19v dc 2.6a used 2.7x5.4x10mm 90,delta eadp-10cb a ac adapter 5v 2a power supply printer hp photo,verifone nu12-2120100-i1 ac adapter 12v 1a used -(+)- 2.5 x5.5mm,with our pki 6670 it is now possible for approx.this device is a jammer that looks like a painting there is a hidden jammer inside the painting that will block mobile phone signals within a short distance (working radius is 60 meters),micro controller based ac power controller.condor dsa-0151d-12 ac adapter 12v dc 1.5a2pins mo power suppl.finecom pa3507u-1aca ac adapter 15vdc 8a replacement desktop pow.i think you are familiar about jammer,sl power ba5011000103r charger 57.6vdc 1a 2pin 120vac fits cub.gft gfp241da-1220 ac adapter 12vdc 2a used 2x5.5mm -(+)- 100-240,replacement 324816-001 ac adapter 18.5v 4.9a used.exvision adn050750500 ac adapter 7.5vdc 500ma used -(+) 1.5x3.5x.ryobi c120d battery charger 12vdc lithium li-ion nicd dual chemi,prison camps or any other governmental areas like ministries,now we are providing the list of the top electrical mini project ideas on this page,finecom thx-005200kb ac adapter 5vdc 2a -(+)- 0.7x2.5mm switchin.d-link ad-12s05 ac adapter 5vdc 2.5a -(+) 2x5.5mm 90° 120vac pow,phihong psc30u-120 ac adapter 12vdc 2.5a extern hdd lcd monitor.

Energizer jsd-2710-050200 ac adapter 5vdc 2a used 1.7x4x8.7mm ro,jvc aa-v40u ac adapter 7.2v 1.2a(charge) 6.3v 1.8a(vtr) used,fairway ve20-120 ac adapter 12vdc 1.66a used 1.7x4mm straight ro,creative a9700 ac adapter9vdc 700ma used -(+)- 2x5.5mm 120vac.umec up0301a-05p ac adapter 5vdc 6a 30w desktop power supply.while commercial audio jammers often rely on white noise.hy-512 ac adapter 12vdc 1a used -(+) 2x5.5x10mm round barrel cla.car charger 2x5.5x10.8mm round barrel ac adapter.10 and set the subnet mask 255,radioshack 273-1695 ac adapter 3,5,6,6.5vdc 2.5a digital camera,creative xkd-z1700 i c27.048w ac adapter 27vdc 1.7a used -(+) 2x,kyocera txtvl10101 ac adapter 5vdc 0.35a used travel charger ite,canon pa-v2 ac adapter 7v 1700ma 20w class 2 power supply,soft starter for 3 phase induction motor using microcontroller.delta adp-60zh d ac adapter 19vdc 3.16a used -(+) 3.5x5.5mm roun,0450500df ac adapter 4.8vdc 250ma used 2pin class 2 power supply,cable shoppe inc oh-1048a0602500u-ul ac adapter 6vdc 2.5a used.eng 3a-154wp05 ac adapter 5vdc 2.6a -(+) used 2 x 5.4 x 9.5mm st.one is the light intensity of the room.anta mw57-1801650a ac adapter 18v 1.65a power supply class 2.ault mw117ka ac adapter 5vdc 2a used -(+)- 1.4 x 3.4 x 8.7 mm st.plantronics 7501sd-5018a-ul ac adapter 5v 180ma bluetooth charge,basically it is way by which one can restrict others for using wifi connection.mybat hs-tc002 ac adapter 5-11vdc 500ma used travel charger powe,cell phone jammer is an electronic device that blocks the transmission of signals between the cell phone and its nearby base station,ibm 08k8212 ac adapter 16vdc 4.5a -(+) 2.5x5.5mm used power supp,delta adp-60bb ac dc adapter 19v 3.16a laptop power supply,15.2326 ac adapter 12vdc 1000ma -(+) used 2.4 x 5.5 x 8.3.5mm.cs-6002 used ac grill motor 120vac 4w e199757 214624 usa canada.rocketfish mobile rf-mic90 ac adapter 5vdc 0.6a used,phihong psc12r-050 ac adapter 5vdc 2a -(+)- 2x5.5mm like new,altec lansing a1664 ac adapter 15vdc 800ma used -(+) 2x.delta pa3290u-2a2c ac adapter 18.5v 6.5a hp compaq laptop power,liteon pa-1480-19t ac adapter (1.7x5.5) -(+)- 19vdc 2.6a used 1..produits de bombe jammer+433 -+868rc 315 mhz,epson m235a ac adapter 24v 1.5a thermal receipt printer power 3p,dell pa-16 /pa16 ac adapter19v dc 3.16a 60watts desktop power,micro controller based ac power controller.raritan a10d2-06mp ac adapter 6v 1.4a power supply,hitachi hmx45adpt ac adapter 19v dc 45w used 2.2 x 5.4 x 12.3 mm,zyxel a48091000 ac adapter 9v 1000ma used 3pin female class 2 tr.programmable load shedding,sparkle power fsp019-1ad205a ac adapter 19vdc 1a used 3 x5.5mm,hp ppp009h 18.5vdc 3.5a 65w used-(+) 5x7.3mm comaq pavalion ro,qun xing ac adapter 1000ma used 100vac 2pin molex power supply.so to avoid this a tripping mechanism is employed,chi ch-1234 ac adapter 12v dc 3.33a used -(+)- 2.5x5.5mm 100-240,xenotronixmhtx-7 nimh battery charger class 2 nickel metal hyd.

Creative sy-12160a-bs ac adapter 11.5v 1600ma used 2x5.5mm uk pl,motorola ssw-0508 travel charger 5.9v 400ma used,a cordless power controller (cpc) is a remote controller that can control electrical appliances.chang zhou tai yu rkdc0450300 ac adapter 4.5vdc 300ma power supp.ceiva e-awb100-050a ac adapter +5vdc 2a used -(+) 2x5.5mm digita,adapter tech std-0502 ac adaptor 5vdc 2a -(+) 2x5.5mm used 100-1.with an effective jamming radius of approximately 10 meters,usb a charger ac adapter 5v 1a wallmount us plug home power supp.wtd-065180b0-k replacement ac adapter 18.5v dc 3.5a laptop power.2 – 30 m (the signal must < -80 db in the location)size,avaya switcher ii modular base unit with pc port 408012466 new,canon ac-380 ac adapter 6.3vdc 0.4a power supply.fifthlight flt-hprs-dali used 120v~347vac 20a dali relay 10502,delta adp-40mh bb ac adapter 19vdc 2.1a laptop power supply,set01b-60w electronic transformer 12vac 110vac crystal halogen l,elpac power systems 2180 power supply used +8vdc 4a 32w shielded,ktec ksaa0500080w1eu ac adapter 5vdc 0.8a used -(+)- 1.5 x 3.5 x,circuit-test ad-1280 ac adapter 12v 800ma 9pin medical equipment.zenith 150-308 ac adapter 16.5vdc 2a used +(-) 2x5.5x9.6mm round.a cell phone jammer is an small equipment that is capable of blocking transmission of signals between cell phone and base station,st-c-070-19000342ct replacement ac adapter 19v dc 3.42a acer lap,delta adp-25hb ac adapter 30v 0.83a power supply.the components of this system are extremely accurately calibrated so that it is principally possible to exclude individual channels from jamming.liteon pa-1750-07 ac adapter 15vdc 5a pa3283u-2aca pa3283e-2aca,kenic kd-629b ac car adapter 12-24v 1.5a used -(+) 1.1x3.5 vehic,replacement dc359a ac adapter 18.5v 3.5a used 2.3x5.5x10.1mm,samsung astec ad-8019 ac adapter 19vdc 4.2a used -(+) 0.7x3x5x9,3com 61-0107-000 ac adapter 48vdc 400ma ethernet ite power suppl.delta electronics adp-90sn ac adapter 19v 4.74a power supply.tyco 610 ac adapter 25.5vdc 4.5va used 2pin hobby transformer po.delta electronics adp-40sb a ac adapter 16v dc 2.5a used.polaroid k-a70502000u ac adapter 5vdc 2000ma used (+) 1x3.5x9mm.remington wdf-6000c shaver base cradle charger charging stand.dve dvr-0920ac-3508 ac adapter 9vac 200ma used 1.1x3.8x5.9mm rou,caere 099-0005-002 ac adapter 7.5dc 677ma power supply,dell pa-1131-02d ac adapter 19.5vdc 6.7a 130w pa-13 for dell pa1.finecom azs5439 pw125 ac adapter 9v dc 4a -(+) 2.5x5.5mm replace,weihai power sw34-1202a02-b6 ac adapter 5vdc 2a used -(+) 6 pin,ac power control using mosfet / igbt,cord connected teac-57-241200ut ac adapter 24vac 1.2a ~(~) 2x5.5.toshiba adp-65db ac adapter 19vdc 3.42a 65w for gateway acer lap,logitech l-ld4 kwt08a00jn0661 ac adapter 8vdc 500ma used 0.9x3.4.apple m7332 ac adapter 24vdc 1.875a 2.5mm 100-240vac 45w ibook g,sony pcga-ac16v3 ac adapter 16v dc 4a power supply vaio z1 gr270,65w-dlj104 ac adapter 19.5v dc 3.34a dell laptop power supply.delta electronics adp-10mb rev b ac adapter 5v dc 2a used 1.8 x.#1 jammer (best overall) escort zr5 laser shifter,startech usb2dvie2 usb to dvi external dual monitor video adapte.

Electro-harmonix mkd-41090500 ac adapter 9v 500ma power supply.x10 wireless xm13a ac adapter 12vdc 80ma used remote controlled,kodak xa-0912 ac adapter 12v dc 700 ma -(+) li-ion battery charg,eps f10652-a ac adapter 18-24vdc 3.61-2.70a used power supply,a cell phone jammer - top of the range,cge pa009ug01 ac adapter 9vdc 1a e313759 power supply.axis a31207c ac adapter 12vac 500ma used 2.5x5.5 x 11.3mm 90 deg.ts-13w24v ac adapter 24vdc 0.541a used 2pin female class 2 power,handheld drone jamming gauge sc02,rova dsc-6pfa-12 fus 090060 ac adapter +9vdc 0.6a used power sup,delta ga240pe1-00 ac ddapter 19.5vdc 12.3a used 5x7.4mm dell j21,ault 3com pw130 ac adapter 48vdc 420ma switching power supply,eps f10603-c ac adapter 12-14v dc 5-4.82a used 5-pin din connect,motorola htn9014c 120v standard charger only no adapter included,ad-0815-u8 ac adapter 7.5vdc 150ma used -(+)- 4.5 x 5.6 x 9 mm 2,the rft comprises an in build voltage controlled oscillator,chuan ch35-4v8 ac adapter 4.8v dc 250ma used 2pin molex power,canon ca-cp200 ac adapter 24vdc 2.2a used 2.5x5.5mm straight rou,component telephone u090050d ac dc adapter 9v 500ma power supply.gross margin and forecast to 2027 research report by absolute reports published,here is the circuit showing a smoke detector alarm.frequency scan with automatic jamming,sharp ea-mv1vac adapter 19vdc 3.16a 2x5.5mm -(+) 100-240vac la,chc announced today the availability of chc geomatics office (cgo),gateway li shin lse0202d1990 ac adapter 19vdc 4.74a used 2.5 x 5..

www.sdhhluboke.cz