Precise Point Positioning is becoming an attractive alternative technique to RTK, removing GNSS system errors to provide global high accuracy positioning, HERE has recently introduced the service HERE HD GNSS Positioning, a cloud-based service that provides sub-meter positioning for devices equipped with GNSS receivers.
Precise Point Positioning, new possibilities for mass market applications
Precise Point Positioning (PPP) correction services have been in the market for a long time to either assist vessels maneuver at ports or for measuring instruments for construction and geodesy. Today, highly precise positioning goes beyond industrial use cases and is available to mass market applications and devices.
Precise Point Positioning services remove GNSS system errors to provide higher accuracy positioning using a single receiver. PPP solutions rely on GNSS satellite clock and orbit corrections, generated from a network of global Continuously Operating Reference Stations (CORS). Once the corrections are calculated, they are delivered to the user via satellite or the internet resulting in dm-level or better real-time positioning without the need for a local base station. PPP enables device users to be located within 0.2-1 meter in an open sky environment, instead of the average 3-5 meters to bring higher accuracy. To achieve ambiguity resolution a PPP service might require some time to converge to decimeter accuracy, but it can reach sub meter accuracy in less than a minute. The convergence time required is dependent on the quality of the corrections and how they are applied in the receiver but for many applications is not an issue.
With multi-constellation being the rule rather than the exception, relying on the additional accuracy provided by Galileo and with the use of PPP corrections, businesses can offer decimeter accuracy for safety critical applications such as autonomous or assisted driving.
A recent example of leveraging PPP correction services is HERE HD GNSS Positioning, introduced earlier in 2020 by HERE Technologies. HERE HD GNSS Positioning is a cloud-based service that provides sub-meter positioning for devices equipped with GNSS receivers, so that it can substantially improve positioning accuracy for average mass market devices globally. With HERE HD GNSS Positioning, joggers have a precise location when running in parks, drivers can enjoy accurate lane-level navigation to take the right highway exit, drones can be tracked with greater precision and fleet operators can accurately re-create routes taken by fleets to aid in post-trip analysis. The service works without any expensive equipment and turns regular mobile devices and GNSS-receivers into precise positioning instruments.
As PPP and PPP-RTK providers are already upgrading to Galileo, the introduction of Galileo High Accuracy Service (HAS) in the future will open up a wide variety of opportunities for the creation of new location-based services. HAS will allow users to obtain a positioning error below two decimetres and it will be based on the free transmission of PPP corrections through the Galileo E6-B signal. The corrections will be available over the internet too.
The main specifications of the Galileo E6-B and E6-C codes became available in January 2019 to the Galileo User Community. These codes can be used for accessing the future Galileo High Accuracy Service (HAS) and Galileo Commercial Authentication Service (CAS). For more details, visit the Galileo GNSS documents section.
Source: GSA