A real survey · Roodefontein, Plettenberg Bay

This is one property, flown once.

Every figure elsewhere on this site now comes from this survey. A smallholding on the Roodefontein road with 16.2 hectares mapped, flown on a single morning in three flights, and reconstructed into the outputs described under what you receive.

The map below is the finished orthomosaic. It is the real thing, not a screenshot: drag it, and zoom until you can read the roof.

Orthomosaic · 1.5 cm/px Drag to pan · scroll to zoom
EPSG:32734 · UTM 34S 8 May 2022
What the flight produced

Three flights, seventy-one minutes,
945 photographs.

The drone flew a nadir grid over the farmstead and two oblique orbits of the wider property. Nadir frames give the map its geometry; obliques see the sides of buildings and the underside of tree canopy, which is what stops a reconstruction collapsing into a flat sheet.

A further 46 frames were flown low and close to the buildings. Those are photographs rather than survey data, and they were deliberately left out of the reconstruction: a frame shot from six metres up pointing almost level sees a wall and a lot of sky, and sky has nothing in it to match. Three of them are at the bottom of this page.

Area mapped
16.2 hectares
Photographs used
945 of 991
Camera
Hasselblad L1D-20c, 20 MP
Survey height
55 m, with a 29 m nadir pass
Ground resolution
1.5 cm/px
Relief across site
44 m
Points measured
211 million
Flight time
71 minutes, one morning
The same property, five ways

Every output on this site, from this one flight.

These are the actual deliverables, reduced for the page. Nothing here is a diagram of what the output would look like.

The complete orthomosaic of the property: pasture, cleared bush, fynbos, a dam, farm tracks and the farmstead buildings, all in one continuous top-down image.
Orthomosaic, whole site955 megapixels
The surface model of the property, hillshaded and tinted from low ground to high, showing gullies, the road cutting and the fall of the land.
Surface model5 cm grid
Contour lines at two metre intervals drawn from the bare-earth model of the property, following the ground rather than the tree canopy.
Contours, bare earth2 m interval
The dense point cloud of the property seen from an angle: millions of coloured measured points describing the surface, buildings and vegetation.
Point cloud211 million points
What this does and does not show

One survey is an example,
not a specification.

The 1.5 cm/px above comes from flying at 55 m with this camera. Fly higher and you cover more ground per battery and resolve less; fly lower and the reverse. What your site needs depends on its size, its terrain and what you want to do with the result, which is why there is no single number on the rest of this site either. What accuracy depends on sets that out properly.

This survey was flown for the landowner. It is shown here as an example of the work with their agreement, and it is not a claim about anyone's property but their own. Certified measurement remains a job for an appropriately qualified professional.

The 46 frames that were not used

Left out of the map. Kept as photographs.

Flown low and close, these are useless to a reconstruction and among the best pictures of the property. You receive both.

The smallholding seen from the air with the sea on the horizon: pasture, scattered bush and the farm buildings among trees.
Looking south32 m
The gabled farmhouse with its corrugated roof and covered stoep, seen from close range with a vehicle parked on the grass in front.
The farmhouse8 m
The farmhouse roof from above and to one side, with a creeper growing across the corrugated iron and dense green bush surrounding the building.
Roof and creeper11 m

Your property, the same way.

One flight, and you have the map, the model and the photographs. They are yours to keep.

Map my property See what you receive