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Jammer's kinematic disturbances (jammer in the vehicle). Speed of the Vehicle Time at Which the Vehicle Passed the Instruments (UTC)
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Understanding the factors that might intentionally influence the reception of global navigation satellite system (GNSS) signals can be a challenging topic today. The focus of this research is to evaluate the vulnerability of geodetic GNSS receivers under the use of a low-cost L1/E1 frequency jammer. A suitable area for testing was established in Sl...
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... maximum distances between the jammer and the GNSS instruments were about 400 m (between A and B, as well as between B and C). The speed of the vehicle and the moment the vehicle passed the instruments are shown in Table 4 Jammer localisation relies on lateration using the best estimations of the distance from the pairs of synchronized geolocated GNSS receivers, as presented on Figure 6. ...Citations
... The intentional nature of jamming distinguishes it from natural interference; it is a deliberate act, with the objective of disrupting communication or navigation systems relying on GNSS signals. UAVs heavily rely on GNSS signals for accurate navigation, and jamming poses a significant threat to UAV operations by causing navigation errors, loss of control, or even complete failure of the UAV's navigation system [42]. Beyond the immediate operational impact, jamming raises security concerns, especially in scenarios where UAVs are deployed for surveillance, emergency response, or other critical applications. ...
... Mitigating the risks associated with jamming requires a combination of technological solutions, regulatory measures, and awareness. Researchers and industry professionals work towards developing resilient navigation systems that can withstand jamming attempts, and regulatory bodies enforce measures to prevent and penalize jamming activities [39][40][41][42][43]. ...
Spoofing, alongside jamming of the Global Navigation Satellite System signal, remains a significant hazard during general aviation or Unmanned Aerial Vehicle operations. As aircraft utilize various support systems for navigation, such as INS, an insufficient Global Navigation Satellite System signal renders Unmanned Aerial Vehicles nearly uncontrollable, thereby posing increased danger to operations within airspace and to individuals on the ground. This paper primarily focuses on assessing the impact of the budget friendly Software-Defined Radio, HackRF One 1.0, on the safety of Unmanned Aerial Vehicles operations. Considering the widespread use of Software-Defined Radio devices today, with some being reasonably inexpensive, understanding their influence on Unmanned Aerial Vehicles safety is crucial. The generation of artificial interference capable of posing a potential threat in expanding Unmanned Aerial Vehicles airspace is deemed unacceptable.
... One major interference is the multi-path effect. Signals might face obstacles in their path and are often obstructed and reflected by buildings, trees, or other large objects [6]. Because of reflection and diffraction, the signals can find their way to the receiver in multiple ways. ...
Global navigation satellite systems (GNSSs) and ultra-wideband (UWB) ranging are two central research topics in the field of positioning and navigation. In this study, a GNSS/UWB fusion method is investigated in GNSS-challenged environments or for the transition between outdoor and indoor environments. UWB augments the GNSS positioning solution in these environments. GNSS stop-and-go measurements were carried out simultaneously to UWB range observations within the network of grid points used for testing. The influence of UWB range measurements on the GNSS solution is examined with three weighted least squares (WLS) approaches. The first WLS variant relies solely on the UWB range measurements. The second approach includes a measurement model that utilizes GNSS only. The third model fuses both approaches into a single multi-sensor model. As part of the raw data evaluation, static GNSS observations processed with precise ephemerides were used to define the ground truth. In order to extract the grid test points from the collected raw data in the measured network, clustering methods were applied. A self-developed clustering approach extending density-based spatial clustering of applications with noise (DBSCAN) was employed for this purpose. The results of the GNSS/UWB fusion approach show an improvement in positioning performance compared to the UWB-only approach, in the range of a few centimeters to the decimeter level when grid points were placed within the area enclosed by the UWB anchor points. However, grid points outside this area indicated a decrease in accuracy in the range of about 90 cm. The precision generally remained within 5 cm for points located within the anchor points.
... The main goal of this study was to find and investigate in detail interference-induced anomalies for different jamming devices in simultaneous open-field experiments of jamming smartphones and geodetic GNSS receivers. Similar studies were conducted previously at the University of Ljubljana, Slovenia, to compare the response of different surveying instruments to the L1/E1 jammer in static [4,5] and kinematic [6] positioning. This followup study uses multi-frequency jammers and includes dual-frequency smartphones from different manufacturers. ...
Smartphones now dominate the Global Navigation Satellite System (GNSS) devices capable of collecting raw data. However, they also offer valuable research opportunities in intentional jamming, which has become a serious threat to the GNSS. Smartphones have the potential to locate jammers, but their robustness and sensitivity range need to be investigated first. In this study, the response of smartphones with dual-frequency, multi-constellation reception capability, namely, a Xiaomi Mi8, a Xiaomi 11T, a Samsung Galaxy S20, and a Huawei P40, to various single- and multi-frequency jammers is investigated. The two-day jamming experiments were conducted in a remote area with minimal impact on users, using these smartphones and two Leica GS18 and two Leica GS15 geodetic receivers, which were placed statically at the side of a road and in a line, approximately 10 m apart. A vehicle with jammers installed passed them several times at a constant speed. In one scenario, a person carrying the jammer was constantly tracked using a tacheometer to determine the exact distance to the receivers for each time stamp. The aim was, first, to determine the effects of the various jammers on the smartphones’ positioning capabilities and to compare their response in terms of the speed and quality of repositioning with professional geodetic receivers. Second, a method was developed to determine the position of the interference source by varying the signal loss threshold and the recovery time on the smartphone and the decaying carrier-to-noise ratio (CNR). The results indicate that GNSS observations from smartphones have an advantage over geodetic receivers in terms of localizing jammers because they do not lose the signal near the source of the jamming, but they are characterized by sudden drops in the CNR.
... For the second part of the selection process, two IoT platforms (alternatives) were chosen -Azure IoT Microsoft and ThingWorx PTC because these platforms were perceived as the most popular by end users [7]. Evaluation of set criteria (populating of decision matrix) was done based on published comparison, as well as qualitative reviews (ibid). ...
... -multipath effects, which are very high on pseudo-range and carrier phase, -cycle slips are common, -carrier-phase availability in really bad conditions is low, and -the satellite geometry is weak. The statistical properties of signal reception conditions vary greatly in different types of positioning scenarios, which differ up to the local environment and surrounding objects, as well as local interference conditions [7], [8]. It depends on a GNSS receiver to detect local obstacles for proper positioning algorithms. ...
Recently, increased interest in the smart city concept has opened up new research and business-like questions. When considering the implementation of Internet of Things (IoT) platform in smart cities it is important that it is chosen adequately. Thus, this paper identifies relevant criteria for IoT platform selection. End users and vendors have evaluated the importance of the proposed criteria. The selection procedure was demonstrated using the PROMETHEE method. Results accredit vendors to offer more suitable platforms, and enable end users and decision makers to better understand and
improve the selection of IoT platforms according to smart city needs.
... Jamming is usually used to prevent a vehicle being tracked through GNSS; however, when used a jammer also impacts other devices that are used for positioning and timing services, including continuously operating reference station infrastructure, which is used for geodetic purposes or autonomous navigation. Earlier studies at the University of Ljubljana showed that none of the professional geodetic and low-cost GNSS receivers used in the experiments had an effective type of full jamming suppression adapted to the chirp jammer, but receivers of newer generations showed a dramatic improvement against jamming [26,27]. This was particularly true for the GLONASS satellite signals, but in some cases also for Galileo and BeiDou, which were found to be less susceptible to interference from the L1 chirp jammer. ...
... In the context of this state-of-the-art overview, the driving motivation for the research presented in this paper is to conduct further experiments, starting with detecting and locating jammers [29], and especially, as a follow-up to the 2019 and 2020 experiments [26,27], by using static jamming of receivers that are in kinematic mode, and to analyse the results so that a better understanding of some of the main factors that influence signal reception during jamming can be obtained. The research is based on the results of previous studies conducted at the University of Ljubljana, which showed that the response of receivers from different manufacturers and generations is unique for each type of receiver tested; however, the newer generation of professional geodetic receivers is much more resistant to jamming [26,27]. ...
... In the context of this state-of-the-art overview, the driving motivation for the research presented in this paper is to conduct further experiments, starting with detecting and locating jammers [29], and especially, as a follow-up to the 2019 and 2020 experiments [26,27], by using static jamming of receivers that are in kinematic mode, and to analyse the results so that a better understanding of some of the main factors that influence signal reception during jamming can be obtained. The research is based on the results of previous studies conducted at the University of Ljubljana, which showed that the response of receivers from different manufacturers and generations is unique for each type of receiver tested; however, the newer generation of professional geodetic receivers is much more resistant to jamming [26,27]. ...
Robust autonomous driving, as long as it relies on satellite-based positioning, requires carrier-phase-based algorithms, among other types of data sources, to obtain precise and true positions, which is also primarily true for the use of GNSS geodetic receivers, but also increasingly true for mass-market devices. The experiment was conducted under line-of-sight conditions on a straight road during a period of no traffic. The receivers were positioned on the roof of a car travelling at low speed in the presence of a static jammer, while kinematic relative positioning was performed with the static reference base receiver. Interference mitigation techniques in the GNSS receivers used, which were unknown to the authors, were compared using (a) the observed carrier-to-noise power spectral density ratio as an indication of the receivers’ ability to improve signal quality, and (b) the post-processed position solutions based on RINEX-formatted data. The observed carrier-to-noise density generally exerts the expected dependencies and leaves space for comparisons of applied processing abilities in the receivers, while conclusions on the output data results comparison are limited due to the non-synchronized clocks of the receivers. According to our current and previous results, none of the GNSS receivers used in the experiments employs an effective type of complete mitigation technique adapted to the chirp jammer.
... A common theme for these investigations of jamming is the focus on code-based GNSS positioning. Carrier phase-based positioning has been investigated by [23] in a real-world experiment where several geodetic receivers were subjected to both static and kinematic L1/E1 band jamming. Positioning accuracy of the receivers in a real-time kinematic (RTK) positioning scenario was examined, and it was shown that, with sufficient jamming power, all receivers would eventually lose the ability to determine a position. ...
... It should be emphasized that, while jamming is not a big issue in the cases analyzed herein, interference and PPD jamming may well be an issue for other receivers. For instance, even if the reference station is not affected, a jammer on the rover side might severely impact the positioning solution, as was also shown in [23]. Several authors, including [14,15], also showed that this was the case for code-based receivers. ...
GNSS signals arriving at receivers at the surface of the Earth are weak and easily susceptible to interference and jamming. In this paper, the impact of jamming on the reference station in carrier phase-based relative baseline solutions is examined. Several scenarios are investigated in order to assess the robustness of carrier phase-based positioning towards jamming. Among others, these scenarios include a varying baseline length, the use of single- versus dual-frequency observations, and the inclusion of the Galileo and GLONASS constellations to a GPS only solution. The investigations are based on observations recorded at physical reference stations in the Danish TAPAS network during actual jamming incidents, in order to realistically evaluate the impact of real-world jamming on carrier phase-based positioning accuracy. The analyses performed show that, while there are benefits of using observations from several frequencies and constellations in positioning solutions, special care must be taken in solution processing. The selection of which GNSS constellations and observations to include, as well as when they are included, is essential, as blindly adding more jamming-affected observations may lead to worse positioning accuracy.
... They produce receivers with signal degradation mitigation solution or equip with addition sensors. Besides significant improvements, local interference from nearby receiver persists, which means the problems need to be resolved in the future [6]. ...
Global Navigation Satellite Systems or GNSS is a space technology that has become an essential element nowadays for positioning, navigation & timing (PNT) with wide range of applications in many civilian sectors as well as across military. The reliability, accuracy and availability of GNSS are highly important especially for critical and precise positioning applications. However, the signals from space are weak and it can be easily blocked, disrupted or compromised by several other threats including intentional and unintentional interferences or jamming. GPS jammer is widely available off the shelf with an affordable price and capable of interfering the GPS signal, and many authorities worldwide have raised concerns and a lot of efforts and research have been put in place to reduce and mitigate the threats. In Malaysia, understanding and countering threats to GNSS/GPS based applications will be a new and unfamiliar discipline for public and organizations. This study intended to provide an overview of the GNSS interferences environment in a local study area, in terms of interference type and the number of activity pattern that were detected. A system called Detector V1 has been used in this study. The result showed that significant interference cases happened in the study area and some of the high power interferences may impact GNSS tracking and precision of the positioning output. The role objective of having this done is to create a public awareness regarding the threat of GNSS interferences to the local users. The content also includes the proposed initiative to overcome the issue.
... Only recently has the development of measurement techniques taken place, allowing for the execution of TSB measurements. Among them, the following may be distinguished: Unmanned Surface Vehicles (USV), which are characterized by high maneuverability and small sizes [11][12][13][14][15][16][17][18], Global Navigation Satellite System (GNSS) geodetic networks providing services of both real-time, as well as post-processing [19][20][21][22][23] and miniature devices for depth measurements [24][25][26][27][28]. Thanks to them, it is possible to carry out bathymetric measurements in ultra-shallow waters with up to centimeter accuracy [29][30][31], as well as in a rapid and reliable manner. Moreover, photogrammetric methods are often used to analyze coastal zone changes, using unmanned [32][33][34][35][36] and manned aircrafts [37], as well as analyzing multispectral images of high [38][39][40][41] and moderate [42,43] resolution. ...
The Territorial Sea Baseline (TSB) allows coastal states to define the maritime boundaries, such as: contiguous zone, continental shelf, exclusive economic zone and territorial sea. Their delimitations determine what rights (jurisdiction and sovereignty) a given coastal state is entitled to. For many years, the problem of delimiting baseline was considered in two aspects: legal (lack of clear-cut regulations and different interpretations) and measurement (lack of research tools for precise and reliable depth measurement in ultra-shallow waters). This paper aimed to define the seasonal variability of the TSB in 2018–2020. The survey was conducted in three representative waterbodies of the Republic of Poland: open sea, river mouth and exit from a large port, differing between each other in seabed shape. Baseline measurements were carried out with Unmanned Surface Vehicles (USV), equipped with Global Navigation Satellite System (GNSS) geodetic receivers and miniature Single Beam Echo Sounders (SBES). The survey has shown that the smallest seasonal variability of TSB (1.86–3.00 m) was confirmed for the waterbody located near the Vistula Śmiała River mouth, which features steep shores. On the other hand, the greatest variability in the baseline (5.73–8.37 m) as observed in the waterbody adjacent to the public beach in Gdynia. Factors conditioning considerable changes in TSB determination were: periodically performed land reclamation works in the area and the fact that the depth of the waterbody increases slowly when moving away from the coastline.
... As we may read from the figure, the maximal power of acquired signals does not exceed 50 dB-Hz. We find that this value is significantly lower when compared to high grade receivers since the latter acquire signals with power reaching even over 50 dB-Hz [6,28,29]. What also transpires from the plots in Figure 2 is that the C/N 0 records are subject to frequent outliers characterized with ultra-low values. This effect holds true for all analyzed smartphones. ...
The new generation of Android smartphones is equipped with GNSS chips capable of tracking multi-frequency and multi-constellation data. In this work, we evaluate the positioning performance and analyze the quality of observations collected by three recent smartphones, namely Xiaomi Mi 8, Xiaomi Mi 9, and Huawei P30 pro that take advantage of such chips. The analysis of the GNSS observation quality implies that the commonly employed elevation-dependent function is not optimal for smartphone GNSS observation weighting and suggests an application of the C/N0-dependent one. Regarding smartphone code signals on L5 and E5a frequency bands, we found that they are characterized with noticeably lower noise as compared to E1 and L1 ones. The single point positioning results confirm an improvement in the performance when the weights are a function of the C/N0-rather than those dependent on the satellite elevation and that a smartphone positioning with E5a code observations significantly outperforms that with E1 signals. The latter is expressed by a drop of the horizontal RMS from 8.44 m to 3.17 m for Galileo E1 and E5a solutions of Xiaomi Mi 9 P30, respectively. The best positioning accuracy of multi-GNSS single-frequency (L1/E1/B1/G1) solution was obtained by Huawei P30 with a horizontal RMS of 3.24 m. Xiaomi Mi 8 and Xiaomi Mi 9 show a horizontal RMS error of 4.14 m and 4.90 m, respectively.
... Today, awareness of the risk of using global navigation satellite systems (GNSS) in our daily lives and in any public or private infrastructure, known as "jamming", is very important. In GNSS positioning, intentional jamming is considered the most disruptive event that drastically affects the reliability and quality of positioning or, in the worst case, makes positioning impossible [1,2]. Receiver manufacturers are well aware of this; hence, they invest a lot of effort in anti-interference features. ...
... In the context of jamming, the driving motivation for the research presented in this paper was to perform some further experiments and to analyse the results in order to better understand some key factors that influence the quality of positioning under different locations of a jammer as well as under different jamming scenarios. Having studied the knowledge of the response of different types of geodetic receivers [2], the researchers extended this study to the problem of the receiver response under the vertical and horizontal jamming profile. The basic research question was, "How do GNSS receivers of the same type react to vertical jamming when the jammer is below or above the horizon of the GNSS receivers?" ...
... The results of a previous study conducted at the University of Ljubljana showed that the response of receivers from different manufacturers and generations is unique for each type of receiver tested [2]. The aim of the present research is to determine the response of several receivers of the same type located in different positions to the same interfering signal. ...
Jamming is becoming a serious threat to various users of global navigation satellite systems (GNSS). Therefore, live monitoring tests are required to estimate the sensitivity range of GNSS receivers under jamming. This study analyses the response of some mass-market and professional-grade receivers to intentional interferences based on different 3D jammer positions. First, the vertical jamming was investigated, followed by a horizontal experiment where the receivers were placed at three locations while the jammer was moving within a triangular area. The aim was to determine a fingerprint of the influence of the L1/E1 chirp jammer on receivers used in the research. The results show that low-cost receivers are much more susceptible to interference, while the latest generation of GNSS geodetic receivers are much more resilient. It is encouraging that positioning in the presence of jamming could be achieved on a larger scale, especially by using professional receivers. An attempt to position the jammer will be left for trials when a more frequency stable device is applied.
