The government told a three-judge bench headed by Justice Dipak Misra that installation of jammers in school buses was “not possible” and they were coming out with steps to deal with the menace of child pornography in its entirety.
The GPS jammer affecting GNSS can be intentional and unintentional ones. Intentional jammers include deceiving jammers and suppressing jammers, of which the suppression jammers are dominant, and they suppress the navigation signals by emitting high power signals, such as broadband, narrowband or continuous wave (CW) . Therefore, this paper focuses on the reduction of the suppressing jamming signals.
Generally, an antenna array for interference suppression is a spatial filter. It is a signal- processing method which makes use of the spatial selectivity of antenna array to filter out the jammers and to improve the SNR. The anti-jamming algorithms based on antenna array are divided into two categories according to their goals. One is the Digital Beam Forming (DBF), which adjusts the main beam automatically to the desired signals. The other is the Adaptive Nulling algorithm], which points the nulls to jammers. The DBF requires the direction information of GNSS signals and its computation is quite complex. As a result, its jamming mitigation performance will degrade severely if errors of the estimation on GNSS signals’ direction increase.
According to a senior ECIL official, the German cell phone jammer were found to be very effective when installed for VVIP security, in prisons and other sensitive establishments. “We have installed them in Chhattisgarh and Jharkhand central prisons where a large number of Maoists are lodged in high security blocks. The security protocol of the Jharkhand Chief Minister includes these gadgets…they have placed order for more jammers now,” the official who preferred not to be quoted said.
The Federal Aviation Administration and the Federal Communications Commission spent two years — from March 2009 to April 2011 — locating just one GPS jammer used on the New Jersey Turnpike. That jammer interfered with an FAA system that provides enhanced navigation signals to aircraft in the vicinity of the airport for precision approach, departure procedures and terminal area operation