Precise Point Positioning
Drop a dual-frequency RINEX observation file for an absolute decimetre-level position — no base station. Precise orbits and clocks are fetched automatically and the solve runs in your browser. For a full quality breakdown of the same file use QC.
Drop a dual-frequency RINEX observation file — or click to choose
GPS (L1/L2), Galileo (E1/E5a) and BeiDou (B1I/B3I), dual-frequency. A full day at 30 s is ideal. Precise orbits & clocks are fetched automatically; everything runs in your browser.
Frequently Asked Questions
- What is Precise Point Positioning (PPP)?
- PPP computes an absolute position from a single receiver — no base station — by using precise satellite orbits and clocks instead of the broadcast ephemeris, plus dual-frequency carrier phase. It reaches decimetre-to-centimetre accuracy where ordinary single-point positioning is metre-level.
- What do I need to upload?
- A dual-frequency RINEX observation file (GPS L1/L2 — C1W/C2W pseudorange and L1C/L2W carrier phase), ideally a full day at 30-second sampling. Hatanaka (CRINEX) and gzipped files are accepted. The precise orbit and clock product (ESA MGEX SP3) is fetched automatically for the file’s day.
- How accurate is it, and does anything leave my machine?
- This is static float PPP: it converges to the decimetre level (centimetre vertical) over a few hours. GPS-only float positioning is geometry-limited in the horizontal; multi-GNSS and integer ambiguity resolution are the path to centimetre. The RINEX file is parsed and solved entirely in your browser — only the public precise-orbit product is fetched (via a CORS proxy).
- Why does it need recent data to be a few weeks old?
- It uses ESA’s precise MGEX orbit/clock product. The final product has roughly a three-week latency; the rapid product (a day or two old) is used as a fallback. Very recent data may not have a precise product available yet.