PPP Systems

Fundamentals
Title	PPP Systems
Author(s)	GMV
Level	Basic
Year of Publication	2011

Precise point positioning (PPP) stands out as an optimal approach for providing global augmentation services using current and coming GNSS constellations. PPP requires fewer reference stations globally distributed rather than classic differential approaches (e.g. RTK), also one set of precise orbit and clock data is valid for all users everywhere, and the solution is largely unaffected by individual reference-station failures. There are always many reference stations observing the same satellite because the precise orbits and clocks are calculated from a global network of reference stations. As a result, PPP gives a highly redundant and robust position solution.

Several software products implementing a PPP processing strategy have been developed recently by government agencies, universities, industries and individuals. Some online PPP services are also available.

PPP Services

Precise Point Positioning (PPP) is a global precise positioning service, since it requires the availability of precise reference satellite orbit and clock products in real-time using a network of GNSS reference stations distributed worldwide.

• GAPS: The University of New Brunswick (UNB) developed the GPS Analysis and Positioning Software (GAPS). According to Leandro et. al. (2007) the algorithms used in GAPS follow more or less standard PPP approaches. GAPS is available as an online processing engine via the web page http://gaps.gge.unb.ca/ppp/. Static as well as kinematic processing is possible. They accept an observation

file in the RINEX 2.10 or 2.11 formats. IGS product files necessary for processing the observations are automatically retrieved from one of the IGS global data centers.