Four GNSS tasks. Clear requirements.
PosFlow serves drone and UAV mapping operators, control and deformation surveyors, CORS and reference-station operators, and geoscience researchers.
Drone & UAV Mapping
A day's flight produces thousands of images and a rover log, and there's no way to know the ground coordinates are trustworthy until the orthomosaic is already built on top of them.
- Inputs
- Rover and base observations from the same flight.
- Workflow & output
- Apex solves your rover log against your own base station log with PPK (kinematic, static, or static-start) and returns a trajectory with per-epoch quality flags before you tag a single photo.
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.
Only the rover log, with no base station observation file from the same flight
A base station RINEX file recorded over the same time window. PPK is differential. It resolves the rover's position relative to the base, so a flight with no base log has nothing to solve against.
Rover and base sessions that don't share a recorded time window
Overlapping observation spans. The solution only covers the window the rover and base recorded together.
Control Surveys & Deformation Monitoring
A benchmark or monitoring point needs a coordinate you can defend years later, not just one that looks stable today.
- Inputs
- A long, continuous dual-frequency observation session.
- Workflow & output
- Static PPP resolves a long-session position on its own, verified by Apex Duo between two independent engines, with full antenna calibration and a formal uncertainty on the result.
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.
A short or frequently interrupted observation session
A long, continuous session. PPP resolves ambiguities through convergence, and a short or broken one may never settle on a stable coordinate.
Single-frequency-only observations
Dual-frequency tracking, at minimum. The solution needs two frequencies to cancel the ionospheric delay a single one carries no way to remove.
CORS & Reference Station Operations
A reference station degrades quietly (a cable goes intermittent, an antenna radome ices over) and the first anyone hears about it is a downstream survey that won't converge.
- Inputs
- Dated observation files or a station feed.
- Workflow & output
- Point the QC Monitor at a station's feed, schedule recurring checks, and get an alert when completeness drops or multipath climbs past a threshold you set, before it reaches anyone downstream.
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.
An observation file with no matching broadcast ephemeris for its date
A dated, standard observation file. Elevation-dependent checks need satellite positions for that date, fetched automatically from the file's own timestamp.
A feed with gaps larger than the scheduled check interval
A shorter check interval than the gap you're trying to catch, or a continuous feed. A monitor can only flag what it has a chance to see.
Geoscience & Research
A result that can't be reproduced or checked isn't a result a reviewer (or a co-author six months later) can trust.
- Inputs
- Observation data, stated methods and independent control.
- Workflow & output
- Every threshold, scoring formula, and precise-product source we use is published, not asserted, so a reviewer can check the method against the number instead of taking our word for it.
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.
A claim with no stated method behind it
The scoring formula and thresholds, published rather than described in general terms, so the number can be checked rather than just cited.
A result with no stated uncertainty
A formal uncertainty alongside the coordinate. A position without one can't be checked against independent control or propagated into further analysis.