Octo for GNSS post-processing
From field RINEX to the accuracy report, almost everything runs from the command line: gfzrnx and RTKLIB check and process in batch, and the RBMC publishes the day's base data under predictable names. Octo builds the batch, flags bad sessions before they reach the office and checks heights in bulk. Choosing the base and method, accepting the vertex and submitting to SIGEF with an ART stay with the licensed professional.
Six possible deliverables, drawn from the research. All of them run on the office computer, with the client's observations, and all of them end up on the desk of the person who signs the work.
Reads each file's header (antenna, height, interval, duration), compares it with the field book and converts between RINEX 2, 3 and 4 with gfzrnx when the office software needs it.
Deliverable: field inventory with discrepanciesBuilds the daily file name from the observation date, downloads each base once from IBGE's public server and decompresses the Hatanaka files.
Deliverable: the day's base folder, no clicksProcesses static relative positioning with RTKLIB and a versioned options file, as a check solution alongside the commercial software the office already uses.
Deliverable: solution per vertex + a second opinionComputes code multipath and counts cycle slips and gaps per satellite, still at the end of the field day, to decide whether to reoccupy.
Deliverable: list of sessions to reviewComputes H = h − N for hundreds of points with the chosen IBGE model and points out which heights from the field diverge.
Deliverable: matches / diverges / outside the grid spreadsheetComputes horizontal accuracy per vertex, compares it with the limit set by the person in charge and gives the reason for each "review". Sends nothing to INCRA.
Deliverable: screening report in CSV and HTMLThe same Octo cycle, applied to GNSS post-processing. Each arm has a narrow role; the ones who choose the method, accept the vertex and sign the work are people.
Receivers, antennas, office software (TBC, Infinity, RTKLIB) and versions, where the RINEX files are stored and what the field book looks like.
SIRGAS 2000 at epoch 2000.4, the contract's height type, the antenna table and the official coordinates of the RBMC bases.
Observations and legal descriptions say where the property is and who owns it: nothing goes to an external service, including AI, without an assessment with the client (LGPD, Brazil's data protection law). Files of unknown origin don't run on production machines.
RTKLIB as the solution or as a second opinion; relative to the RBMC or IBGE-PPP; 15 s or 1 s data; commercial gfzrnx or the vendor's converter.
Scripts with logging, exit codes, a versioned options file and a test run on a session the office has already processed by hand.
Compares the batch solution with TBC's, Infinity's or IBGE-PPP's on the same vertex, by the numbers, not by the absence of errors.
Report and spreadsheet for the technical lead. Submission to SIGEF belongs to the accredited professional, with their ART.
The version of each program, options file, base used, limit and result. One property's batch is never assumed ready for another.
Octo works in a support role. It does not accept vertices, does not choose the height type, does not submit to SIGEF and does not issue an ART: that belongs to licensed and accredited professionals.
The criteria Octo uses to choose. Always with the version installed at the office and the license the client holds.
| Task | Path | Notes |
|---|---|---|
| Convert RINEX 3/4 to 2.11 | gfzrnx | Commercial license for companies |
| Multipath in RINEX 2 | teqc +qc | Legacy: discontinued in 2019; does not read RINEX 3 |
| Multipath in RINEX 3 | Anubis or a custom script (MP1, L1 − L2) | The threshold is a technical decision |
| Receiver binary to RINEX | convbin or the vendor's converter | Check antenna and height |
| The day's RBMC base | dados_RINEX3/AAAA/DDD/ on IBGE's geoftp | Available the next day |
| Static relative in batch | rnx2rtkp -k conf -p 3 -r X Y Z | Official base coordinate |
| Official Brazilian PPP | IBGE-PPP, through the web form | No documented API |
| Independent check | CSRS-PPP or AUSPOS | Separate reference frame and epoch |
| Physical heights in bulk | MAPGEO2015 (N) or hgeoHNOR2020 (normal) | Height type set by the person in charge |
| Process in TBC or Infinity | Octo prepares the input and reads the exported report | No command-line GNSS batch found |
Three steps. Each one only makes sense after the previous one has shown results in your office.
A proposal, not a promise
You send the RINEX files from a job and Octo returns an inventory, quality screening and a height check.
Baselines also go through RTKLIB, with the RBMC bases downloaded automatically, alongside the software the office signs off with.
What comes in from the field goes into the nightly batch; in the morning, the person in charge reads one report, not one per session.
Every point below has a source published by the responsible agency (Planalto, INCRA, IBGE, ANAC, DECEA), by the vendor or by the project. ABNT standards appear only by number and title. The sources are in the next section.
4
points with a published source, each with its reference shown alongside.
SSSS00BRA_R_AAAADDD0000_01D_15S_MO.crx.gz.Source: RBMC repository on IBGE's geoftpOcto prepares everything, but it does not sign. The document of record stays with whoever is accountable for it.
Surveys, calculates, organizes and produces the documents: spreadsheets, reports, drawings and draft legal descriptions.
Deliverable: material ready to checkThe licensed professional checks what Octo delivered before signing. If something doesn't add up, it goes back to Octo with the correction.
Step: checked by the person who signsOcto does not sign. Designs, technical reports, ART/RRT, statements of account and any official document are still signed by the licensed professional at the company or agency: here, the surveying or cartographic engineer with an ART filed with CREA, or the surveying technician with a TRT filed with CRT; for rural properties, the professional accredited by INCRA, who submits to SIGEF.
Signature: licensed professional, with ART or TRTDocumentation from IBGE, INCRA, the IGS, GFZ, Geoscience Australia and Leica used in the research, consulted on Oct 31, 2026.
The assessment starts with a job your office has already processed, without touching what was delivered. You get the screening, the height check and a proposal for what can be automated, and you decide with that in hand.