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Is a LocataLite a Pseudolite?

Thursday, 1 November 2012

No.  Many experts, upon hearing that Locata networks “terrestrially replicate GPS”, immediately jump to the incorrect conclusion that Locata technology is based around a device the industry has long known as a pseudolite.

These “pseudo-satellites” were designed in the 1970’s to be just that – satellite stand-ins when the USAF needed to terrestrially test GPS-like signals before there were GPS satellites in the sky.

A pseudolite transmitter outputs a ranging signal, traditionally one of the GPS signals on, or near, the GPS frequencies. However pseudolites do not synchronize to each other, which is a critical requirement for the creation of a radio-positioning system.

A pseudolite has no knowledge of neighboring pseudolites and therefore cannot synchronize to other pseudolites.

Many attempts have been made by countless companies and researchers over the years to synchronize pseudolites through the use of GPS time, cables or atomic clocks. However, in the 40+ years spanning the existence of pseudolite devices, there have been no successful commercial applications. In fact, none of the many different approaches has ever delivered a widely-accepted, real-world operational system, despite the enormous technical effort, time and money put into pseudolite development.

Locata had developed a TimeLoc synchronization technology (see CORE TECHNOLOGY section above) that solves the fundamental problem of deploying a ground-based equivalent of GPS, something that pseudolites clearly have not achieved in the 40+ years they have existed.

A LocataLite is not a pseudolite. A LocataLite is “ a device that generates TimeLoc”.

Importantly, Locata signals are not the same as GPS or any other satellite signals. The Locata system architecture is designed to create a ground-based positioning system which is a true GPS-replica, not a ground-based test capability for a satellite system (which is what pseudolites were originally designed to do). The Locata system was designed from the outset with the goal of working exactly like a satellite system, as observed by the “User Segment” – a LocataNet user sees the Locata system as a “terrestrial GPS constellation”.

Put in classic GPS terms, the LocataNet handles both the Space segment and the Ground segment via the LocataLite transceivers and TimeLoc. A user sees a system that is a one-way ranging system providing pseudorange and carrier-phase measurements from a network of synchronized transmitters. This is exactly the same description used to describe the GPS satellite constellation.

Locata is the only technology in the world that can do this.