Description
Starpoint & Starpoint Pro
PPP
Precise Point Positioning is a method to calculate precise positions at the centimeter level using a single receiver in a global reference framework. PPP delivers real-time centimeter-level corrections anywhere on the planet, without the need for a local base station or RTK network.
It combines precise satellite orbits and clocks with undifferenced dual-frequency observables. In areas where a traditional real-time kinematic (RTK) network does not exist, PPP is a viable solution that enables the user to collect data nearly as efficiently as Network RTK using a single GNSS receiver.
How it works
PPP differs from Double Difference relative positioning used in RTK in that it does not require the observation of the same set of satellites as observed by the base station. PPP provides absolute positioning information to the rover with respect to the base stations. The PPP rover receives precise orbit and clock data information from the processing center which is connected to a network of reference stations.
Time to solution
It will take up to 10-30 minutes for the PPP solution to converge at startup but can be 1-5 minutes from a known point or near TopNet areas.
CPPP
(Convergence Point Precise Positioning): A convergence stage of calculation of autonomous coordinates of a single receiver, when using dual-frequency code and carrier phase measurements and the data on precise orbits and clocks of navigation satellites.
PPPN
(Point Precise Positioning Normal): Positions are calculated using dual-frequency code and carrier phase measurements of a single GNSS receiver and the data on precise orbits and clocks of navigation satellites. Integer ambiguities, however, were NOT fixed (their FLOAT estimates were used instead).
PPPF
(Point Precise Positioning Full): Positions are calculated using dual-frequency code and carrier phase measurements of a single GNSS receiver and the data on precise orbits and clocks of navigation satellites. Integer ambiguities were FIXED.
Datum used
Currently, PPP uses ITRF 2014 Epoch 2010.0. ITRF 2014 employs velocity models. Transformation parameters from it to WGS84 are currently not available. If using standalone PPP on a project that has known coordinates, a localization (one-point minimum) will need to be performed to determine the transformation parameters of the project.
What PPP services does GeoShack offer?
Starpoint Pro is our stand-alone PPP subscription from Topnet Live. This allows the user to survey using the PPP technique anywhere they can receive the corrections. Currently, Topcon is offering 2 options for receiving the PPP corrections, L-band and NTRIP. L-band is a satellite-based correction service.
Corrections are transmitted in the L-band frequency range. This method can be used anywhere in the world where the L-band satellites are visible. This is for land-based applications only, not marine based.
NTRIP is distributed via the Internet. This method can be used where access to the Topnet Network is available. It is not be available if the internet connection is lost. This can be used in land-based and marine applications.
What do I need to use PPP?
To use the Topcon PPP subscriptions, you will need the following: A receiver that is capable of all constellations and L-band – Topcon: HiPer-HR, HiPer-VR, NET-G5, or MR-2, Sokkia: GNR5 or GRX3 • GNSS firmware 5.4 or higher • Subscription to Starpoint or Starpoint Pro • MAGNET Field v7.3.1 or higher.
Please note that Starpoint uses the GPS and GLONASS constellations only while Starpoint Pro uses full constellations (GPS / GLONASS / BDS / Galileo)
Contact your GeoShack Sales Professional for more information, to schedule a meeting, or to get a product demonstration.
