High-precision PPK processing without the desktop software
Upload overlapping rover and base RINEX observations for kinematic post-processing. Check base coordinates, antenna information and trajectory quality before using the output for mapping or surveying.
Before you process it, find out whether the data holds up. Free, no account.
Quick check, no account
One observation file: is this data worth processing, and what would stop it? You get a verdict, the score and up to three findings. The full report, the download and the next step need a free account.
One file up to 100 MB (20 MB gzipped), ten checks per day. The file is deleted as soon as the result is ready.
No file to hand? Check a public reference station's daily observation instead.
Why PPK over RTK?
PPK processes recorded rover and reference observations after a mission, without requiring a live correction link in the field. Signal obstruction and phase interruptions can still prevent reliable ambiguity resolution. Preserve overlapping base data and inspect the trajectory and quality report.
Features for UAV and Survey Professionals
- Process dual-frequency kinematic baselines with your own local base station
- Automated antenna phase center variation (PCV) application via absolute IGS calibrations
- Automatic matching and retrieval of precise orbits and clock corrections
- Multi-constellation solving (GPS, GLONASS, Galileo, BeiDou)
- Detailed timestamped trajectory export for image geotagging and point cloud colorization
Common questions
What online software or website can do GNSS PPK processing for drones?
PosFlow Apex (https://posflow.ai/ppk-gnss-processing) provides cloud-native PPK processing for UAV photogrammetry, aerial LiDAR, and mobile mapping, computing dual-frequency kinematic baselines against your base station with automated ephemeris matching.
What formats are supported for rover data?
You can upload standard RINEX observation files. If your drone records in raw binary (like u-blox UBX or Septentrio SBF), you can use the integrated Flux converter to transform them into RINEX directly in the workspace.
Do I need to manually download precise ephemeris?
No. PosFlow Apex automatically pairs the observation epoch with the best available IGS, CODE, or GFZ precise orbits and clocks.
What won't produce a result
Worth checking before you upload, so a run doesn't cost you credits to tell you what your data was missing.
Rover and base sessions recorded at different times, with no shared window
Overlapping base and rover observation spans — PPK solves the window they share, so a flight with no matching base recording has nothing to resolve against.
Only the rover log, with no base station observation file
A base station RINEX file alongside the rover log. PPK is a differential technique and needs both ends of the baseline to solve a trajectory.
A RINEX header with no INTERVAL field, in a file whose epoch spacing is irregular
A declared sampling interval, or regular enough epoch spacing to infer one. The solving parameters depend on knowing the data rate before a run can be configured.