Photogrammetry -Types of Photographs
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This document discusses different types of aerial photographs used in photogrammetry. It describes vertical photographs taken directly downward, low oblique photographs taken at a 30 degree angle, and high oblique photographs taken at a 60 degree angle. For each type it provides the characteristics, such as the area covered, ability to measure distances and directions, visibility of relief and the horizon. Vertical photographs cover a small area but allow measurement of distance and direction on flat terrain. Low oblique photographs cover a larger area in a trapezoid shape and provide more familiar perspective. High oblique photographs cover the largest area but do not allow measurement and distort relief.
Photogrammetry -Types of Photographs
- 1. Photogrammetry Types of Photographs By Prasenjit Bhowmick Asst. Professor DREAM INSTITUTE OF TECHNOLOGY Civil Engineering Dept.
- 2. Types of photographs vertical, horizontal, oblique. Topics
- 3. Types of Photographs Photogrammetry Photographs Errestrial Taken from ground based cameras Aerial Taken from air based cameras
- 4. Types of Aerial Photographs Photogrammetry Aerial Photographs According to orientation of camera axis According to Lens system According Film properties
- 5. 1. According to orientation of camera axis Photogrammetry 1Vertical Oblique • depends upon the angle of the camera • with respect to the earth's surface
- 6. Vertical Photographs Camera points should straight down Allowable tolerance is ± 3° with plumb line. Photogrammetry
- 7. Characteristics Axis perpendicular to the earth Covers small area Photogrammetry
- 8. Characteristics Distance and directions from flat terrain Relief not readily apparent Photogrammetry
- 9. Relationship of the vertical aerial photograph with the ground Photogrammetry
- 10. Low Oblique Photographs Photogrammetry Camera inclined about 30° from the vertical
- 11. Characteristics - Covers a large area Ground area covered as trapezoid, square or rectangular Photogrammetry
- 12. Characteristics – Familiar than viewing from the top of tall object. Photogrammetry
- 13. Characteristics – No distance & Azimuth can measure with Scale. Does not show the horizon Photogrammetry
- 14. Relationship of low oblique photograph to the ground Photogrammetry
- 15. High Oblique Photographs Camera inclined about 60° from the vertical Limited military application Photogrammetry
- 16. Characteristics - Covers a very large area Distances and directions are not measured Photogrammetry
- 17. Characteristics - Relief may be quite discernible but distorted as in any oblique view. Photogrammetry
- 18. Characteristics - The horizon is always visible. Photogrammetry
- 20. Vertical Aerial photograph. Low-oblique Aerial photograph. High-oblique Aerial photograph Pc: Kahola, Kansas. Photogrammetry