Internet compatibility is important for GPS function. For instance, searching for a business in your general vicinity is completed by a signal from your smartphone or mobile device to find relevant locations for your current location. The combining of GPS technology and the Internet allows your location to be revealed, but in most cases, GPS must be enabled on your device to work properly.
This is revolutionary in the industry because it proves that technology evolves with society and that adaptation occurs to add convenience to everyday life. Computer programs are developed to work in coordination with GPS locating systems. In most cases, the location is within a city block, which is rather accurate given how geographical grids work. Plans were made for roughly satellites to orbit for GPS purposes. A total of 32 satellites is currently in orbit, having an immense impact on life as a whole.
GPS technology is used around the world. Signals sent from space help scientific research. Without orbiting satellites, knowing the exact location of a space station would be impossible. It would also be impossible to follow airplanes and passenger planes as well. Logistics management, when distracted driving is an issue, helps fleets locate vehicles to update vendors and customers regarding shipments.
Fleet managers can also track the habits of their drivers to see how each person drives if they follow traffic laws and if the equipment is subject to any kind of abuse. Global positioning systems have had a major impact on the way society lives. The technology is relevant in every industry in the world in some capacity. Social media platforms have integrated GPS software to allow for geotagging and location posting.
Essentially, GPS technology is making the happenings of the world detectable, capable of being tracked and more preventable. Advances in GPS devices has made them more accurate and useful. Military Targeting Military targeting is made possible from GPS devices being attached to airborne items to track missile paths, bombing patterns and track aircraft flight patterns. Safety While Boating Using GPS devices for marine use such as satellite weather reports, satellite phone communications, and even depth reading technology is ideal.
Logistics Logistics management, when distracted driving is an issue, helps fleets locate vehicles to update vendors and customers regarding shipments. AJ Agrawal. See AJ Agrawal's Profile. AJ Agrawal is a writer, speaker, and entrepreneur. It was the first GNSS system fully available to the users, through the creation of a constellation of satellites.
All the considerations provided here for the GPS system are extensive to the other ones, with minor modifications. The first is available to all users, regardless of the application, while the second is restricted only to DoD authorized users, being accessed via cryptographic techniques Balvedi Unlike these kinds of GPS signals, which are encrypted and can be authenticated, the civilian ones and those who do not have the DoD authorization were never intended for safety- and security-critical applications.
However, currently, the GPS system supports many critical applications not only for military, but also for civilian and commercial users worldwide.
Fourteen of sixteen critical sectors of the economy depend on the GPS signals navigation, precision agriculture, financial market, communication, etc. However, as demonstrated previously in Faria et al. These actions result from its high sensitivity, becoming vulnerable to high signals.
Nowadays, on internet open sources , it is very easy to find not only jamming equipment, but also spoofing ones to buy, at lower prices than expected. Besides, several tutorials can be found on websites and YouTube, detailing how to spoof and jam vectors, especially drones. It is just to google it and one can find security experts raising alarm over online drone hacking instructions Russon In addition, successful spoofing experiments on standard receivers have been increasingly reported Tippenhauer et al.
The increased availability of programmable radio platforms, as will be shown later, leads to a reduced cost of attacks and to a high vulnerability of GPS systems. In this context, this article aims to evaluate the susceptibility of complex GPS-dependent systems to spoofing, which is shown as an advanced technique of interference, where corrupted PNT signals are transmitted to the receiver, overlaying the true GPS signals. This procedure presents a high potential of damage, so that is very difficult to identify and to countermeasure.
Information on the capabilities, limitations, and operational procedures helps to identify vulnerable points and detection strategies, reasons that justify this work. In order to illustrate the high vulnerability of such systems, it stands out the case of the US RQ Sentinel. Figure 1 depicts the incident, not presenting accurate information of the procedures and infrastructure that Iran used to perform such task.
It is worth noting that US uses an encrypted GPS code, hindering the success of interference, but, in this case, not being sufficient to prevent the Iranian action.
For that, right-circularly polarized waves are continuously emitted in three carrier frequencies, L1, L2 and L5 respectively The PRN code is a binary sequence, which, in addition to identifying the satellite, makes the spread spectrum signal, allowing all satellites to transmit at the same frequency. The transit time is calculated from the received signal correlated with its replica, generated in the receiver, enabling the calculation of its position. This is possible when establishing communication with, at least, four satellites. In addition to the PRN codes, the navigation message also modulate the carriers, including information of the broadcast ephemeris, satellite clock corrections, almanac data, ionosphere information and satellite health status.
The analysis presented in the present paper is restricted to the study of the effects on the L1 carrier signals, which is the frequency used by the SPS users, the great majority of civil and military institutions outside the United States. The GPS system specification provides, for transmission, a power about 27 watts or These low power level signals explain the high susceptibility to intentional jamming and spoofing.
The antenna of a GPS system has omnidirectional characteristics. Its radiation pattern should provide reception of all GPS signals within the reception hemisphere of the antenna from horizon to horizon, at all elevations.
follow link On the other hand, interfering signals generally have low elevation angles, where receiving antennae present lower gains, on the horizon. The gain does not vary with the azimuth, but with the elevation angle, as can be seen in Fig. This technique is quite complex and cause major damage to military and high-value civilian operations when not identified.
Because of the high risk that it offers, just a few detailed information is open-access, although some of them can be found Tippenhauer et al. The simplest form of spoofing, or spoofing level 1, uses a GPS signal simulator to generate a false signal, containing multiple satellite GPS signals. After generating the signal, radio frequency is radiated toward a victim receiver. The main deficiency shown in this technique is the desynchronization between the false and the true GPS signals, since they will not present the same phase. This desynchronization does not allow the processing of the false signal, so acting as noise and, if the power level is enough, it can cause the victim receiver to miss the original signal, thus acting as a simple jammer and alerting the operator to a possible spoofing Warner and Johnston A more efficient variation of spoofing, also known as spoofing level 2, is the one in which the attacker previously knows the position and speed of the victim receiver.
This attack can be accomplished using a simulator and a portable GPS signal receiver receiver-spoofer , which must be positioned close to the target, so that they receive the same signal. Based on this signal, the receiver-spoofer creates a false one.
If this technique is performed correctly, the victim receiver will display all PNT information, based on malicious signal. In order to conduct a spoofing task, initially a correlation between the corrupted and the original signal must be performed. When the peak of correlation of the corrupted signal is aligned with the original one, the power of malicious signal is increased. Although this technique is highly complex, experiments show that it is possible and feasible to be implemented Warner and Johnston Figure 3 depicts the process of control of the receiver DLL, where it is possible to observe the correlation between the code generated in the receiver and the GPS signals original and corrupted ones.
As can be seen, after the correlation of the signals, the malicious one mocks the victim receiver, becoming the main signal provide information to the receiver. Finally, a third spoofing technique, known as spoofing level 3, is based on a set of receivers-spoofers, in a coordinated way to remove some possible countermeasures that can be implemented based on spatial discrimination.
This technique is the most complex and therefore the most expensive and difficult to achieve. In Humphreys et al.
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Meaconing shows to be less expensive but generates time delays between signals Tippenhauer et al. GPS spoofing is discussed analytically in Kuhn , showing that it is possible to manipulate military and civilian GPS signals by pulse-delaying, or replaying individual navigation signals with a delay.
These different possible models of attack require a variety of countermeasures focusing on avoiding collateral effects, what is discussed in John ; Kuhn ; Papadimitratos and Jovanovic a ; b ; Warner and Johnston In a close future, countermeasures shall rely only on modifications of the receivers, once those that could be implemented in the signals, or in the satellites themselves, have low probability of implementation, due to the high complexity.
In literature, just a few publications Motella et al. Aiming to check and validate the previously described concepts, some experiments were designed, addressing different levels of intentional interference spoofing in different kind of receivers, from the simplest automotive receivers to more complex ones aeronautical receivers.
Thus, spoofing level 1 could be evaluated, as well as the power level required to an effective interference. Initially, a test was designed with modulated signal spoofing to verify the robustness of different kinds of receivers. The experimental setup, as depicted in Fig. In order to isolate the receivers from any interference or of original GPS satellite signals, the tests were performed in a semi-anechoic chamber. This experiment aimed to test each one of the receivers for their susceptibility to spoofing level 1, radiating the GPS signal generated by the NB software.
The power of each one of the satellites can also be controlled, as well as the relative power scale, the pseudo-range, the Doppler shift and the multipath.