Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. If you continue browsing the site, you agree to the use of cookies on this website. See our User Agreement and Privacy Policy.

Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. If you continue browsing the site, you agree to the use of cookies on this website. See our Privacy Policy and User Agreement for details.

Like this presentation? Why not share!

- Priciple of aerial photography and ... by srinivas2036 6167 views
- Aerial photography abraham thomas by Sumant Diwakar 5518 views
- Lecture 1-aerial photogrammetry by virajain 13788 views
- Lecture on photogrammetry by Waleed Liaqat 14268 views
- Introduction to aerial photography ... by srinivas2036 4500 views
- Geometry and types of aerial photog... by Pooja Kumari 3778 views

6,440 views

5,689 views

5,689 views

Published on

Published in:
Education

No Downloads

Total views

6,440

On SlideShare

0

From Embeds

0

Number of Embeds

8

Shares

0

Downloads

367

Comments

0

Likes

3

No embeds

No notes for slide

- 1. GE 178 Lecture 5:Principles of Aerial Photography andPhoto Scale Determination
- 2. Aerial Photo (Image) vs Map• Images central projection, non-uniform scale actual features• Maps orthogonal projection, uniform scale symbols
- 3. Orthogonal vs Perspective Projection
- 4. Orthogonal vs Perspective Projection
- 5. Orthogonal vs Perspective Projection
- 6. Orthogonal vs Perspective Projection
- 7. Vertical Photography
- 8. Vertical Aerial PhotographCharacteristics• tilt ≤ 3° from the vertical• scale is approximately constant throughout the photo• p=i=n• within limitations, a vertical air photo can be used as a map substitute• most common format is a 9 by 9 inch photograph
- 9. Vertical Aerial PhotographNegative plane f (focal length) = C (principal distance) O f=CPositive plane Hmge (flying height) p=i=n Mean ground elevation
- 10. Elements of a Vertical Photograph
- 11. Fiducial Marks• optically projected geometric figures located at either the four corners of a photograph, or on the four sides of a photograph• define the coordinate axes and geometric center of a single aerial photograph• Intersection represents the principal point of the photograph
- 12. Fiducial Marks and Principal Point
- 13. Fiducial Marks
- 14. Three Photo Centers1. Principal Point – geometric center of the photograph; intersection of the line normal to the image plane through the PC2. Nadir – point vertically below the camera at the time the photo was taken; intersection of the plumb line through the PC with the image plane3. Isocenter – point halfway between the principal point and nadir; point intersected by the bisector of the angle between plumb line and optical axis
- 15. Three Photo Centers Ground PPoint Isocenter Nadir
- 16. Kinds of Photography or camera according to focal length (f)• Wide-angle (f = 6 inches)• Normal-angle (f = 12 inches)• Superwide-angle (f = 3.5 inches)
- 17. PhotoScale
- 18. Photoscale of Vertical PhotoRecall: distance on photo f photoscale distance on ground HBut what if not all the required values are given initially, and instead some other parameters are known?
- 19. Determining PhotoscalePhotoscale may also be determined according to:• Smallest detail and resolution• C-factor and desired minimum contour interval• Expected accuracy• Enlargement from photo to map in the instrument
- 20. Smallest detail and resolution• Resolution – smallest distance that a feature on the ground is still discernible on the image/photo 1 resolution photoscale s p smallest detail
- 21. Smallest detail and resolutionExample: The smallest detail that needs to be seen on the photograph is 1 foot in length. If the resolution of the photo is 0.1 mm, determine the photoscale.
- 22. Smallest detail and resolutionSolution: 1 photoscale 3000
- 23. C-factor and desired minimum contour interval• Contour interval – difference in elevation between consecutive contour lines flying height H C factor contour interval h• C-factor range from 1200 to 1500
- 24. C-factor and desired minimum contour intervalExample: The C-factor of the instrument is given to be 1500. If the desired contour interval is 1 meter, determine the photoscale.
- 25. C-factor and desired minimum contour intervalSolution: 1 photoscale 9000
- 26. Expected AccuracyMean square error of horizontal position of points: mh 0.1 H 0.0001H 10-4 H%ο – per mil; equivalent to 1/1000For Cadastral Survey: mh = 10 cm (urban) = 30 cm (rural)
- 27. Expected AccuracyExample: Determine the photoscale for an urban area if the camera to be used is a wide-angle camera.
- 28. Expected AccuracySolution: 1 photoscale 6000
- 29. Enlargement from photo to map• Using the stereoplotter, there will be an enlargement from the photo to the stereomodel: Z enlargement Cwhere: Z = projection distance for stereoplotter C = f = projection distance of camera
- 30. Enlargement from photo to mapExample: A map with scale 1:5000 was derived from a stereomodel with a scale of 1:8000, using a stereoplotter. The projection distance of the stereoplotter is twice the focal length of the camera. Determine the scale of the photograph that was used to generate the stereomodel.
- 31. Enlargement from photo to mapSolution: 1 photoscale 16000
- 32. END OF LECTURE

No public clipboards found for this slide

×
### Save the most important slides with Clipping

Clipping is a handy way to collect and organize the most important slides from a presentation. You can keep your great finds in clipboards organized around topics.

Be the first to comment