ENSURING OPERATIONAL RESILIENCE OF SATELLITE NAVIGATION AT SEA

Abstract

The article examines the challenges of global navigation satellite systems (GNSS) functioning at sea under unintentional and intentional interference. The article reviews the vulnerability of GNSS, the methods of protection against interference and the ways of mitigating their impact based on the marine concept of positioning, navigation and time synchronization (PNT). The main goal of this concept is the guaranteed obtaining of reliable data on coordinates, navigation and exact time due to the combined use and comparison of indication for disparate systems and sensors under the influence of natural or intentional interference (attacks) on ship's GNSS equipment. The article analyzes various open sources of information to identify two methods of ensuring the integrity and accuracy of PNT data according to IMO documents and standards. The first method is the detection and direct countermeasures against attacks on shipboard GNSS equipment. The article determines that the most common and easy-to-implement type of attacks are jamming attacks of satellite signals, unlike the more complex and challenging spoofing attacks. The main approach to protection against jamming attacks is spatial signal processing using adaptive marine antenna arrays with a controlled pattern. Examples of modern practical developments of adaptive antenna arrays are given. The second method to ensure reliable PNT data is the use of alternative navigation systems, redundant capabilities and non-traditional methods using the existing systems. Technical solutions in this method have limitations due to the requirements for the vessel’s conventional navigation and radio communication installation. IMO has suggested structures of multisensor and multisystem receivers for obtaining reliable PNT data. These structures combine primary data from different systems based on different principles, such as satellite, terrestrial and augmented correction systems, vessel navigation data and reference systems. The processed PNT data must be accompanied by accuracy and integrity indicators. Keywords: positioning, navigation, time synchronization, jamming, spoofing, spatial processing, antenna arrays, cyber risks, information protection.