Types of Aerial Photography || Photogrammetry

Aerial photography (or airborne imagery) is the taking of photographs from an aircraft or other flying object. Platforms for aerial photography include fixed-wing aircraft, helicopters, unmanned aerial vehicles (UAVs or "drones"), balloons, blimps and dirigibles, pigeons, kites etc.

Types of Aerial photographs: Aerial photographs are of different types which are as follows:

A) Types of aerial photographs on the basis of orientation of camera axis:

 i. Vertical photograph: An aerial photograph taken with the camera axis/optical axis coinciding with the vertical to the ground is known as vertical photograph.

ii. Tilted photograph: An aerial photograph in which the camera axis is unintentionally tilted by small amount (less than 3 °) from vertical/perpendicular to the ground is known as tilted photograph.

iii. Oblique photograph: An aerial photograph taken keeping the camera axis intentionally tilted from the vertical is known as oblique aerial photograph. The amount of tilt ranges from 30° to 60 °. The advantage of oblique photographs is that they cover large area and they also provide side view of features.

Oblique photographs are of two types –

Low oblique: Oblique photographs in which horizon is not seen. Tilt is 30°.

High oblique: Oblique photographs in which horizon is seen. Tilt is 60°.

High Oblique

Low Oblique

B) Types of aerial photographs on the basis of angle of coverage:

i. Narrow angle photograph: Angle of coverage is less than 60°.

ii. Standard or Normal angle photography: Angle of coverage is of the order of 60°.

iii. Wide angle photograph: Angle of coverage is of the order 90°.

iv. Superwide of Ultrawide photograph: Angle of coverage is of the order of 120°.

C) Types of aerial photographs on the basis of special properties of films, filters and photographic equipments:

i. Panchromatic: Records only single band data (visible region of spectrum).

ii. IR: Records only red and IR portions of EMS.

iii. Color: Records all reflections of visible portion in color or natural colors.

iv. Color IR: Records spectral colors and IR in combination resulting in false colors.

v. Thermal imagery: Records only thermal IR emissions of objects.

vi. Radar imagery: Records reflection of radar waves.

vii. Spectrazonal: Records only selected part of the spectrum.

D) Types of aerial photographs on the basis of lens system:

i. Single lens photograph.

ii. Multiple lens photographs.

·        Three lens photograph (Trimetrogon photograph).

·        Four lens photograph. –

·        Nine lens photograph.