Module 1
From Photos to Maps
turns overlapping into an , a , a and a . Whether it works depends on and — decided before the drone ever takes off.
Part A
Mapping vocabulary
Open every card. Each has a diagram — you’ll need these words in every later module.
0/12 opened
Part B
Output explorer
Same site, six products. Each one answers different questions — and hides different problems.
Product
Week
Week 6: Roof / exterior
Orthomosaic
All photos stitched and corrected to a true top-down map.
✓ Answers: Where things are; lengths and areas on the ground.
✕ Can’t: No heights. Walls are invisible from straight above.
Which product answers it?
- How tall is the soil stockpile?
- How long is the parking lot, for the progress report?
- Is a label legible on one electrical box?
- Show the owner the building in 3D context.
Hands-on lab
Practice Mosaic: build an orthomosaic yourself
Place 12 real-looking drone photos by GPS, match their tie points, deal with a blurred photo and a stray from another flight, choose seamlines, and georeference to ground control.
Part C
Overlap simulator
Change altitude and overlap and watch the camera footprints. Then probe any spot to see why it is strong, weak, or a gap.
Flight settings
GSD ≈ 1.6 cm/px · footprint 65 × 49 m
A photo every 14.6 m along the route
Linked to side overlap: wider spacing = less side overlap.
Route direction
Site week (surface heights)
- Gap 0%
- Weak 12%
- Fair 64%
- Strong 24%
- Redundant 0%
Photos
48
4 routes
GSD
1.6 cm
per pixel
Flight time
3 min
12% of one battery
Roof overlap
26% / 63%
side / front at 8.7 m
Why? — probe a spot
Grid E-3 · 80 m E, 48 m S of NW corner · surface 8.7 m
3photos see
this spotWeak
this spotWeak
1–3 photos. Too few viewpoints to triangulate reliably — expect holes and noise.
What you're seeing
Ground coverage looks fine, but on the roof side overlap drops to 26%. Tall objects are closer to the camera, so each photo covers less of them.
Challenge
Week 7 site. ≥ 98% fair-or-better, ≥ 85% strong, ≤ 170 photos, one battery (≤ 25 min).