What is a Photogrammetric Block and How Multiple Flights Combine Into One Model
A "block" in photogrammetry refers to the entire collection of overlapping images that get processed together as one connected mathematical unit. For a small site, this might be a single flight's worth of photos. For a mega survey project, a block can span multiple flights, multiple days, even multiple drones, all stitched into one seamless final model.
10,000+
Images in a large project block
1 model
Final seamless output despite multiple flights
15%
Recommended flight overlap at block boundaries
Zero
Visible seams in properly blocked survey
Why Block Boundaries Matter
Insufficient overlap at flight boundaries creates weak connections
If two adjacent flights within a large block do not overlap sufficiently, the bundle adjustment has fewer connecting points to tie them together accurately, potentially creating a subtle discontinuity or accuracy drop right at that boundary.
How Large Blocks Are Managed
1
Zone Planning
2
Boundary Overlap
3
Distributed GCPs
4
Unified Processing
Multi-Session Blocks Over Time
| Scenario | Block Handling Approach |
|---|---|
| Single day, multiple flights | Combined into one block directly, consistent lighting conditions |
| Multi-day large project | Careful GCP consistency and boundary overlap across all days |
| Weather-delayed remaining sections | New flights matched to existing GCP network for seamless integration |
Large project blocks often span multiple flight days, all carefully planned to combine seamlessly into one final model.
Why This Planning Discipline Matters
Mega aerial surveys that span days or weeks depend entirely on careful block planning to deliver one consistent, accurate final product rather than a patchwork of inconsistent sections. See our mega aerial survey services.
Get a Same-Day Quote on WhatsApp Back to all articles