+91 98765 43210 | info@asav.com | Mon – Sat, 09:00 – 19:00 IST
Noida, Uttar Pradesh 201301
  1. Home
  2. Services
  3. Photogrammetry
  4. Aerial Triangulation
Photogrammetry

Aerial Triangulation

Block adjustment, camera calibration and residual reporting that downstream products can rely on.

Aerial Triangulation — representative deliverable
Overview

Aerial Triangulation

Aerial triangulation is the foundation of every other photogrammetric product, and the one step where cutting corners is least visible. An adjustment that converges is not the same as an adjustment that is correct; systematic error can hide comfortably inside an acceptable-looking RMSE.

We run block adjustments with proper attention to tie point distribution and image connectivity, control point weighting and identification quality, self-calibration where the camera warrants it, and residual analysis that looks for spatial pattern rather than only at aggregate statistics. Blunders in control are detected and reported rather than absorbed by the adjustment.

The deliverable includes the exterior orientation, the calibration result and a full residual report by point and by image — enough for an independent reviewer to accept the adjustment on its merits rather than on trust.

What you receive

Every item below is issued in your own template, with your layer conventions, title block and revision scheme.

  • Exterior orientation parameters for every image in the block
  • Interior orientation and self-calibration results where applied
  • Tie point measurement with connectivity and distribution analysis
  • Ground control point identification and measurement report
  • Bundle adjustment residuals by point, by image and spatially plotted
  • Blunder detection report on control and tie observations
  • Independent check point verification with RMSE by axis
  • Adjusted block report suitable for client or authority acceptance
  • Stereo model setup ready for downstream compilation

Production detail

Key production parameters for Aerial Triangulation
Typical turnaround1–3 weeks per block by image count
Block sizesTens to tens of thousands of frames
Imagery handledLarge-format digital, film scans, UAV, satellite stereo
Typical accuracySub-pixel RMSE on tie points; control residuals within project tolerance
CalibrationSelf-calibration with additional parameters where justified
Output formatsAdjustment report, EO / IO parameter files, project files for downstream use
RevisionsReadjusted until the specification is met

Software and formats

We work in your toolchain. If something you use is not listed, ask — the list below is only what we use most.

Agisoft MetashapeTrimble Inpho / MATCH-ATSOCET SETERDAS IMAGINE / LPSPix4DPython analysis tooling

Frequently asked

Yes, and we will report honestly what accuracy is achievable rather than presenting a weak adjustment as a strong one. Sparse control shifts the burden onto tie point quality and block geometry, and we will tell you where confidence is lowest and whether additional control would be worth collecting.

Where the camera and block geometry justify it, and with the additional parameters reported so the result is auditable. Self-calibrating a well-calibrated metric camera on a weak block does more harm than good, so it is a judgement rather than a default.

Through residual analysis, iterative reweighting and leave-one-out testing on suspicious points. Bad control is reported to you rather than downweighted quietly, because a control blunder often indicates a problem in the survey that you will want to know about.

Yes — scanned film blocks with fiducial-based interior orientation, which is common in change detection and legacy mapping projects. Scan quality governs achievable accuracy and we will assess that before committing to a tolerance.
Step 1 of 4 in Photogrammetry

Send one aerial triangulation job and see how we work

Scope, price and programme come back in writing before anything starts. Most first projects are a single deliverable so you can judge us on output, not on a pitch.

Call an engineer