Vol.:(0123456789) Acta Geodaetica et Geophysica https://doi.org/10.1007/s40328-019-00261-9 1 3 ORIGINAL STUDY Review of NavIC signals under class II jamming based on power and auto‑correlation function monitoring Priyanka L. Lineswala 1  · Shweta N. Shah 1 Received: 4 February 2019 / Accepted: 24 June 2019 © Akadémiai Kiadó 2019 Abstract In the near future, the upcoming Navigation through Indian Constellation (NavIC) system will be used for navigation services in India. All services provided by the NavIC receiver must be reliable and resistant to threats. Therefore, the real-time NavIC signal is exam- ined under intentional software defned radio based chirp-jamming by diferent methods. Since the NavIC signal is available for all the time, jamming scenario has been analysed through power spectral density by calculating the spectral energy distribution per unit time. Furthermore, the received signal is examined through the auto-correlation function and the signal strength monitored at receiver. The dynamic jamming scenario is used for sur- vey and lead to the main observations. For example, the satellites IRNSS-1E, 1F and 1G are more susceptible to interference in such scenario and if the dynamic receiver is closer to interference source, the jammer becomes a serious threat which can block the NavIC signal. Keywords Navigation through Indian Constellation (NavIC) · Interference · Jammers · Power spectral density (PSD) · Auto correlation function (ACF) · Carrier to noise density ratio (C/N 0 ) 1 Introduction The upcoming Navigation through Indian Constellation (NavIC) will support India’s criti- cal infrastructure such as law enforcement, transportation, communications and fnancial transactions, etc. In the future, it will be a vital source of information with signifcant eco- nomic benefts for India. The NavIC is an Indian Regional Navigation System (IRNSS) developed by the Indian Space Research Organization (ISRO). The IRNSS constellation is fully operational with seven satellites named as “IRNSS1”-B, C, D, E, F, G and I. These satellites transmit navigation signals for Standard Positioning Service (SPS) users and Restricted Service (RS) users on both L5 and S band. The SPS signals are based on Code Division Multiple Access (CDMA) with a Binary Phase Shift Key (BPSK (1)) modulation. * Priyanka L. Lineswala plineswala@gmail.com 1 Electronics and Communication Department, SVNIT, Surat, India