🖼️🖼️🖼️ → 🗺️

Three photos of the ground overlapping at the edges, lined up to make one long strip.

🎒 What you need

the shared phone camera
a long stick, a broom handle or a safe raised spot
tape, and a flat area to photograph such as a yard or garden bed

✋ Do this

Hold the phone as high as you safely can, pointing straight down. Take one photo.
Take three steps sideways and take another — but make sure about a third of the first photo is still in this one. That overlap is the whole trick.
Keep going in a straight line for five or six photos, always with the same height and the same overlap.
Look at them side by side on the screen. Find the same stone or leaf appearing in two photos — point at it. That shared thing is how photos get joined.
Print or sketch them and lay them out overlapping to make one long picture of the ground.
Now do it again from lower down. Notice you see more detail but need far more photos to cover the same ground.

💡 Why it works

A drone mapping a field flies straight lines like a person ploughing, taking photos with a big overlap. Software finds the same points in overlapping photos and stitches them into one huge map. Fly low and you get fine detail but a slow job; fly high and you cover ground fast but see less. Every mapping pilot chooses between those two, every single flight.

🔥 Challenge

Map something small and messy from above — a rubbish patch, a vegetable bed, a goat pen — with six photos. Can someone else recognise the place from your strip alone?

📖 New words

overlapthe part of the ground that shows up in two photos

stitchingjoining many photos into one big picture

🖼️

Photo Stitcher

Tap when you have finished this module.