The information on orbital parameters, navigation signals and technical characteristics of systems and networks in the radionavigation-satellite service (RNSS) (space-to-Earth, space-to-space) operating in the bands 1 164-1 215 MHz, 1 215-1 300 MHz, and 1 559-1 610 MHz are presented in this Recommendation.

Today global navigation systems have become a part of our everyday life. It is part of many useful things and assisted people in many ways. It is part of the marine, aircraft and traffic issues – from private user up to logistic cooperation. Also it is used in agricultural companies for precise farming as well as for information systems in all kind of tasks like geology, archeology, hydrology and a lot more. In the sector of engineering, it supports and guides the construction machines.

As of February 2007, a Tide Gauge (TG) was set up in the Pasaia Harbour, in northern Spain (Figure 1). The main reason for such location was the existence of a Permanent GNSS Station and the access to the Internet and electricity in the AZTifacilities 15 m away.

BeiDou is the Chinese pronunciation of the Big Dipper, which consists of seven stars located exactly at the north sky. Chinese people used BeiDou for identifying directions as long back as the ancient times. They also invented the world’s first navigation device based on terrestrial magnetism, the ancient compass, whose Chinese pronunciation is Sinan.

The project involves the establishments of a full complement of SBAS consisting of 15 Indian Reference Stations (INRES), 3 Indian Land Up-link Stations (INLUS), 2 Indian Master Control Centers (INMCC), 2 Geo-Stationary Navigation Payloads and with all the associated software and communication links.

Some of this publicity relates to the UK’s developments in the area of detecting GNSS interference, specifically the GAARDIAN program (for GNSS Availability, Accuracy, Reliability anD Integrity Assessment for Timing and Navigation). This was a wide collaboration between government, academia, and industry to develop a robust system for analyzing interference phenomena associated with GPS and eLoran systems and the effects on their use in safetyand mission-critical applications.

WAAS provides very precise navigation service, with both horizontal and vertical guidance over the Continental United States (CONUS) and a large portion of Alaska, Canada, and Mexico. Other countries and regions of the world also have fielded or are fielding similar systems. WAAS and each of these other systems are known as a Satellite Based Augmentation System, or SBAS. As envisioned at its inception, WAAS today provides service from enroute through approach.

Consciously or not, all humans are navigators, so it is without wonder that satellite navigation has swiftly become a backbone of modern civilisation. All of the sudden, situation awareness and management become significantly improved by introduction of the helpful and inexpensive technology that provides positioning services of unprecedented quality.

GNSS 2D positioning accuracy is well defined. According to the receiver model, the software, the positioning Mode, the available corrections used, the 2D positioning accuracy vary from few meters to mm. However the altimetry positioning with GNSS is less accurate than 2D one. Without an accurate Geoid reference earth surface, the levelling survey by GNSS couldn’t be done with sufficient accuracy needed for several fields of survey like construction or water management projects.

Despite the good performance of GPS, there are more than a few GNSS vulnerabilities and threats. Categorisation into unintentional and intentional is sometimes done to aid understanding. Unintentional disruptions include natural phenomena such as high levels of ionospheric disturbance and solar flares, as well as man-made phenomena including system errors (satellite or signal), and unwanted radio frequency transmissions (TV, microwave communications, radar, …).