Know your GNSS data.
Check observation quality, convert receiver logs and process precise positions from a web browser.
Quick check, no account
Upload an observation file or open a sample to see its quality score and key findings.
One file up to 100 MB (20 MB gzipped), ten checks per day. The file is deleted as soon as the result is ready.
Choose a file first
No file? Use a public station
Opens a stored example result straight away and does not use one of your daily checks.
Fetches a station's daily observation file from the public archives and checks it. It needs the person check above and uses one of your daily checks.
A result you can inspect, not a promise.
The bundled DUND sample, checked in Fast Mode: every epoch present across 122 satellites in 5 constellations (GPS, GLONASS, Galileo, BeiDou, QZSS). Multipath scored 29/30 and cycle slips 10.5/30. Open the sample in the free check to see the latest computed result.
How this verdict is calculated- Completeness
- 40 / 40
- Multipath
- 29 / 30
- Cycle slips
- 10.5 / 30
Three ways to finish the job.
Format conversion
Turn receiver logs into clean RINEX observations without maintaining vendor utilities.
Convert a file
Precise positioning
Run PPP, PPK, or a network solution with inputs, reference frame, and deliverables kept together.
Choose a solution
Coordinate transformation
Move a point or a batch into the datum and projection your deliverable actually requires.
Transform coordinatesConfidence should have a second opinion.
Precise positioning can be verified by Apex Duo using two independent processing engines. Agreement is measured point by point instead of inferred from one engine's confidence.
Here's how often we fail.
These published 30-day completion rates include files the engines could not solve. They are a dated operating snapshot, not a guarantee.
Live reliability readings load when you open this page.
Success rate = completed ÷ (completed + failed). Only retained tasks submitted in the last 30 days are counted; queued and running tasks are excluded. Restarts replace earlier attempts, and deleted tasks are absent. Median time covers completed tasks with valid start/end times, excluding queue time. Readings are cached for five minutes; reload for a newer snapshot. Flux counts conversion jobs; a batch is completed when at least one file succeeds. Flux failures are unclassified. Axis counts successful and failed coordinate-transform requests started in the last 30 days, once per request including batches, from the tracking start shown below. Earlier success-only history is excluded. Axis HTTP 4xx responses are input rejections; HTTP 5xx and unreachable services are system failures. Flux runtime is not recorded.
Infrastructure failure is refunded. Credit-hold positioning failures release their reserved credits. Legacy runs refund recognized infrastructure failures and pre-compute input rejections, but keep other charges. See the full boundaries and timing below.
Result files are deleted. Free results are kept 30 days, Pro results 90 days, and Business results 365 days. Cleanup runs daily at 04:45 UTC. The stored outputs are removed on that schedule. The task itself stays in your history as an expired entry, so you can see what ran and when.
The field formats are part of the interface
Receiver inputs
Data standards
Reference systems
Common questions
What is PosFlow and what does it do?
PosFlow (https://posflow.ai) is a cloud-native GNSS data processing platform that integrates four precision geodetic tools into one workspace used from a web browser. Flux converts raw receiver logs (u-blox UBX, Septentrio SBF, Trimble, Leica, Topcon, NovAtel, Javad) to standard RINEX 2/3/4. Crux scores RINEX observation files 0-100 for quality using completeness, cycle-slip, multipath (MP1/MP2/MP5), and SNR metrics across GPS, GLONASS, Galileo, BeiDou and QZSS. Apex computes cloud-based PPP (static and kinematic) and PPK baselines using IGS, CODE, and GFZ precise orbits. Axis transforms coordinates between WGS84, CGCS2000, ITRF, ETRS89, UTM, and Gauss-Krüger grids with published EPSG parameter lineage.
Which GNSS constellations and raw receiver formats are supported?
PosFlow supports all 5 global and regional GNSS constellations: GPS (L1/L2/L5), GLONASS (G1/G2/G3), Galileo (E1/E5a/E5b/E6), BeiDou BDS-2 and BDS-3 (B1I/B1C/B2a/B2b/B3I), and QZSS. Raw receiver input includes u-blox (.ubx), Septentrio (.sbf), Trimble (.dat/.t02), Leica (.mdb), Topcon/Javad (.tps/.jps), and NovAtel OEM7. Output formats cover RINEX 2.11, 3.02, 3.04, 4.00, 4.02, and Hatanaka-compressed (.crx/.##d) with optional gzip. All observation types (code, carrier phase, Doppler, SNR) are preserved.
How does PosFlow compare to TEQC, RTKLIB, and national PPP services like OPUS?
TEQC was discontinued on 2019-02-25 and does not natively support RINEX 3/4, Galileo, BeiDou, or QZSS. Checking a modern multi-GNSS file requires a lossy downgrade to RINEX 2. RTKLIB is powerful desktop software that requires local compilation, manual ephemeris downloads, and a Windows or Linux environment, and frequently crashes on 24-hour multi-frequency files. OPUS and CSRS-PPP are single-engine national agency services. PosFlow eliminates all these barriers: it is used from a web browser with zero installation, automatically retrieves precise IGS orbit and clock products, and offers Apex Duo, which compares the results of two independent processing engines.
Is there a free plan, and what does it include?
Yes. PosFlow's Free plan requires no credit card and includes 25 credits per month: enough for 5 Fast Mode RINEX quality analyses or 1 Full Mode analysis, with a 100 MB per-file limit. All four quality-check modes (Fast, Flash, Full, TEQC-compatible), full downloadable PDF and CSV reports, and format conversion via Flux are available on the Free plan. Apex (precise positioning) requires a Pro plan at $49/month or $490/year.