ABSTRACT GPS-based systems have been widely used in different critical sectors, including civilian and military applications. Despite of being able to provide great benefits, under certain circumstances they show to be highly vulnerable to intentional interferences. In this context, this article aimed to evaluate the susceptibility of different complex GPS-dependent systems to intentional interferences, focusing on the technique known as spoofing. This technique presents a high complexity and a great potential for damaging/deceiving complex systems, besides being difficult to identify and to implement countermeasures. Complex systems, like mobile phones, automobile receivers and aircraft receivers were submitted to different levels of spoofing, in free space and in a semi-anechoic chamber, being corrupted with low power levels of interference.

ABSTRACT The GPS is a satellite navigation system that provides location and time information. Such a system currently supports critical applications for military, civil and commercial users worldwide and is accessible to any operator by using a single GPS receiver. However, although being too dependent on GPS signals, just a few of these applications present some kind of countermeasure to electromagnetic attacks, showing a high level of vulnerability to intentional attacks. In this paper, we pose questions and situations related to security and vulnerability of different kinds of platforms/vectors and systems which directly afflict the situational awareness of operators. Experiments were made with different general GPS receivers as a function of distance and incidence angle, showing that they fail to work even at low jamming powers (−25 and 0 dBm at 10 m). More complex GPS systems, such as aeronautical receivers, were also tested, losing completely the tracking at −30 dBm, when a 0° (levelled) and 10 m far electromagnetic jamming signal is incident on its antenna. A specific open source, free software (JammPy) allows extending these experimental results, providing a roadmap and estimating how much jamming power is necessary to cause damage to these systems.

ABSTRACT: Directed Infrared Countermeasures (DIRCM) are used to protect aircrafts against missiles with infrared (IR) guidance. They are employed by military and civilian aircrafts, drawing away the guidance system of a missile as it attempts to lock onto the IR signature of the turbines. Unfortunately, the protection provided by these devices generates risks and challenges that must be overcome. In this paper, investigations on DIRCM risks to fighter aircraft pilots are carried out. Different kinds of lasers employed in actual DIRCMs are analyzed and the results show that, depending on their frequency (wavelength), damages can occur up to a distance of 4.8 km. The transmittance through the canopy of an F-5 fighter aircraft is evaluated and its effects on the IR propagation are predicted by the use of software called Counter-Measurements in PYTHON (CMePy). Results show that, even when there are interfaces between the pilot and the source of radiation, damages can occur, showing the importance of this investigation to the right understanding of this subject and future mitigations.

ABSTRACT: Contemporary digital systems must necessarily be based on the "System-on-Chip" (SoC) concept. Especially in relation to the aerospace industry, these systems must overcome some additional engineering challenges concerning reliability, safety and low power. An interesting style for aerospace SoC design is the GALS (Globally Asynchronous, Locally Synchronous) paradigm, which can be used for Very Large Scale Integration - Deep-Sub-Micron (VLSI_DSM) design. Currently, the major drawback in the design of a GALS system is the asynchronous interface (asynchronous wrapper - AW) when being implemented in VLSI_DSM. There is a typical AW design style based on asynchronous controllers that provides communication between modules (called ports), but the port controllers are generally subjected to essential hazard, what decreases the reliability and safety of the full system. Concerning to this main drawback, this paper proposes an AW with robust port controller that shows to be free of essential hazard, besides allowing full autonomy for the locally synchronous modules, creating fault tolerant systems as much as possible. It follows the Delay Insensitive (DI) model interacting with the environment in the Generalized Fundamental Mode (GFM) without the need to insert any delay elements. Additional delay elements, although proposed by some previous work found in literature, are not desirable in aerospace applications. The proposed interface allows working on Ib/Ob mode, showing the DI model is more robust than the QDI model and, therefore, it does not need to meet isochronic fork requirements nor timing analysis. Once an interface presenting similar properties was not found in literature, the proposed architecture proved to have great potential of implementation in practical VLSI_DSM designs, including the aerospace ones, once it overcomes the main engineering challenges of this kind of industry.