Global Navigation Satellite Systems Engineering, Policy, and Design
Integrity for Navigation Land Users (INLU) addresses the difficult task of adapting air-based position integrity solutions to land-based activities such as vehicle and rail travel.
By Inside GNSS
In the past two decades, satellite navigation systems have undergone great development. The development of new generations of global navigation satellite systems (GNSS), represented by GPS III, Galileo, and the BeiDou global system (BDS), is rapidly advancing.
By Inside GNSS
Figures 1 – 10Q: Do modern multi-frequency civil receivers eliminate the ionospheric effect?
By Mark Petovello
Equations 1 – 4
EquationsGNSS is the technology of choice in most applications due to its dedicated infrastructure, Earth coverage, medium to high accuracy, and large market penetration. Most of the applications, including those we download on our smartphones, are in the category of Location Based Services (LBS). However, there are many other services and businesses that rely heavily on GNSS performance and reliability. For instance, Intelligent Transportation Systems (ITS) make extensive use of GNSS technology and this dependence will only grow in the future.
By Inside GNSS
Two aircraft flying at the same altitude
Figures 3 & 4Motivation and Background
By Inside GNSS
EquationsThe advent of multiple constellations provides the opportunity to eliminate geometry weakness as a source of satellite-based augmentation system (SBAS) unavailability. GPS users occasionally encounter areas where an insufficient density of satellites exists to support all desired operations. This most often occurs when a primary slot satellite is out of service. However, adding one or more constellations easily compensates for this geometric shortcoming. In fact, we may now experience the opposite problem of having more satellites that can be tracked by a receiver.
By Inside GNSS
