2. DEFINITION
• Identifying and recognizing objects in the aerial
photograph and then judging their significance in the
photograph.
• Oblique photographs are normally easy to interpret.
3. Factors to assess to identify a feature :
Shape
Theform of an object on an air photohelps to identify theobject. Regularuniform shapes often indicate a
human involvement.
Size
A measure of theobject's surface area (e.g. single-lane vs. multi-lane highways).
Tone/Colour
The colourcharacteristics of an object, relative tootherobjects in the photo, are used toidentify the feature
(e.g. sand has a bright tone, while waterusually has a dark tone; tree species can be determined by the colour
of their leaves at certain times of the year).
4.
5. Pattern
Similar to shape, the spatial arrangement of objects (e.g. row crops vs. pasture) is also useful to identify an
object and its
Shadow
A shadow provides information about the object's height, shape, and orientation (e.g. tree species).
Texture
Texture is the frequency of the change in tone in the photographicimage. As the photoscale is
reduced, the texture of the given object becomes progressivelyfinerand eventually dissapears.
6. Association/Site
Associating the presence of one object with another,or relatingit to its environment,can help
identify the object (e.g. industrial buildings often have accessto railwaysidings; nuclear power
plantsare often locatedbeside large bodies of water).
7. Applications:
Agriculture
•crop type classification
•Crop condition classification
•Crop yieldestimation
•Mapping of soil characteristics
•Mapping of soil managementpractices
Forestry
•Forestcover
•Type of forest
•Vegetation density
•Deforestation
•Forest fires