Construction projects require two flights, a mapping flight and an oblique flight.

Equipment

Drone: Capture obliques with a multi-copter UAS with gimbal mounted camera. A DJI Phantom 4 Pro is a good drone for this purpose.

High-resolution camera: 5472×3648 pixel (12 MP) resolution minimum as provided by, for example, the Phantom 4 Pro or Zenmuse X4S cameras.

Relative position accuracy:
Horizontal: 1.5 m Vertical: 0.5 m

Absolute position accuracy:
Horizontal: 5 m Vertical: N/A

File format

Images must be JPEG and contain metadata (GPS location, relative altitude, gimbal pitch, gimbal yaw, gimbal roll and timestamp)

MAPPING FLIGHT

Ground sample distance (GSD):
2.7 cm/px (1.1. in/px)
Approximate altitude: 91.4 m (300 feet) above ground level (AGL)

Gimbal pitch:
Nadir (straight down)
-90 degrees from horizon

Overlap:
70% front overlap, 70% side overlap

Flight area:
24 hectares (60 acres) per mission
Approximately 12 megawatts or less

OBLIQUE FLIGHT

Altitude:
76.2 to 91.4 (250 to 300 feet) above ground level (AGL)

Gimbal pitch:
Oblique, -15.0 to -45.0 from horizon

Flight area:
6.1 hectares (15 acres) per mission
Approximately 3 megawatts or less

Inner Facing Images:
Typically 8 image captured at 130 m (600 ft) radius from the center in 8 principal compass directions.

Outer Facing Images:
Typically 8 image captured from the center of the site in 8 principal compass directions.