Software walkthrough — DJI Terra point cloud to Civil 3D features
The hook
Modern surveyors live in a software ecosystem: Trimble Business Center, Carlson Survey, Civil 3D, Star*Net, OPUS, Pix4D. Each tool has its strengths; each has gotchas. Knowing what to use when — and what each can't do — is core PS knowledge.
| Tool | Best for | Watch out |
|---|---|---|
| Trimble Business Center (TBC) | GNSS post-processing, network adjustment | Trimble-specific defaults; expensive license |
| Carlson Survey / SurvCE | Field data collection + office processing | Well-loved by veteran surveyors; less polished UI |
| Civil 3D | Drafting, design, surfaces, alignments | Heavy software; learning curve significant |
| Star*Net | Independent least-squares network adjustment | Doesn't do GNSS processing — pair with TBC/RINEX tools |
| OPUS | Free static GNSS processing for U.S. | NAD83 realization-specific; check the report |
| Pix4D / Metashape | Drone photogrammetry → ortho + point cloud | GCPs critical; results only as accurate as inputs |
Memorize these
Concepts that show up on the exam
Closure check
Every traverse, level loop, and GNSS network gets a closure check. The first sanity gate.
Network adjustment
Least-squares solution distributing error across redundant observations. Reports σ₀, residuals, error ellipses.
Reduction to grid
Ground distances multiplied by the combined scale factor to get state-plane grid distances. Skip this and traverse closures look terrible.
Coordinate transformation
Converting coordinates between datums or projections. NAD27 ↔ NAD83 ↔ WGS84. Use NGS-published transformations (NADCON, HARN).
Test yourself
How well did it stick?
A quick 5-question check on Surveying Principles and Computations. See where you stand and what to review.