This document provides an overview of vertical photographs in photogrammetry. It discusses key assumptions and definitions for vertical photographs, including that the optical axis is exactly vertical [1]. Near-vertical photographs can have small intentional tilts of 1-3 degrees [2]. Geometry, scale, relief displacement, and methods for determining flying height from vertical photographs are described through examples [3].

1. © 2019 Dr. Sarhat M Adam
BSc in civil Engineering
Msc in Geodetic Surveying
PhD in Engineering Surveying & Space Geodesy
Note – Figures and materials in the slides may be the authors own work or
extracted from internet websites, Materials by Duhok or Nottingham
universities staff and their slides, author's own knowledge, or various internet
image sources and books example (Element of Photogrammetry by wolf).
Lecture 6: Vertical
Photographs

2. Introduction
◼ If the optical axis is exactly vertical, the resulting photograph is termed
truly vertical.
◼ Photographs containing these small unintentional tilts (1 to 3) degree are
called near vertical or tilted photographs.
◼ This lecture will assume that photographs are vertical.
◼ Other assumptions are that the photo coordinate axis system has its origin
at the photographic principal point.
◼ Also, all photo coordinates have been corrected for shrinkage, lens
distortion, and atmospheric refraction distortion.

3. Geometry of Vertical photo
Source: Elements of Photogrammetry
with application in GIS, 4th edition,
2014 McGraw Hill

4. Scale over flat terrain
Source: Elements of Photogrammetry
with application in GIS, 4th edition,
2014 McGraw Hill

5. Scale over variable terrain
Source: Elements of Photogrammetry
with application in GIS, 4th edition,
2014 McGraw Hill

6. Scale over variable terrain

7. Average photo scale
• An average scale to define the overall mean scale of a vertical photograph
taken over variable terrain.
Scale variations due to changing flying heights

8. Example

9. Example

10. Example
Example

11. Gr. Coord. From V . Photo
Source: Elements of Photogrammetry
with application in GIS, 4th edition,
2014 McGraw Hill

12. Gr. Coord. From V . Photo

13. example

14. Relief Displacement on V photo
Relief displacement is the shift or displacement in the photographic position of an
image caused by the relief of the object, i.e., its elevation above or below a selected
datum.
Simulated flyting height photo

15. Relief Displacement on V photo
• Relief displacement increases with increasing radial distance to the image.
• Vertical heights of objects such as buildings, poles, etc., appearing on aerial
photographs can be calculated from relief displacements.

16. example

17. Flying Height of a Vertical Photograph
Accurate flying heights can be determined even though the endpoints of the ground
line lie at different elevations, regardless of the locations of the endpoints in the
photo. This procedure requires knowledge of the elevations of the endpoints of the
line as well as of the length of the line.

18. Example