Aerial photogrammetry ppt 1

Advanced Surveying- Aerial Photogrammetry Part-I

1. Aerial Photogrammetry Unit No 5 Presentation on Presented by Mr .Amol V. Ghogare Assistant Professor, Civil Engineering Dept. SRES, SCOE, Kopargaon .

2. Photogrammetry- Introduction ►photo = "picture“, ► grammetry = "measurement“, therefore photogrammetry = “photo-measurement”

3. Aerial Photogrammetry – Aerial photogrammetry is a method of collecting information by using aerial photograph or remote sensing technology using electromagnetic spectrum such as infrared, gamma or ultraviolet rays. Aerial photogrammetry (survey ) can provide information of many things which are not visible from ground. 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,  kites etc. Field Work:- Flying Photography Ground control plotting Uses:- Land survey mining Archeology Monitoring wild life & inspect population

4. Comparison b/w Maps & Aerial Photogrammetry Sr No Maps Aerial Photogrammetry 1 Takes linear & angular measurements of terrain Takes photograph of terrain & showing all details 2 Elevation of object determine directly by plotting contour Elevation of object can not determine directly 3 Plotting & reading common to users details of objects shown by sign & symbols Aerial photograph views not familiars to users needs special technique to read 4 Economical uneconomical 5 No confusing details & easily recognizable Confusing details, not easily identified 6 No distortion caused by tilt & relief displacement Distortion of details of terrain caused by tilt & relief displacement

5. Types of aerial Photograph Vertical Photograph Tilted Photograph (unintentionally tilted) Oblique Photograph (Intentionally tilted) a] Low Oblique b] High Oblique

6. Vertical Aerial Photograph An aerial photograph taken with the camera axis/optical axis coinciding with the vertical to the ground is known as vertical photograph.

7. 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.

8. Oblique photograph An aerial photograph taken keeping the camera axis intentionally tilted from the vertical is known as oblique aerial photograph. 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 upto30 °. High oblique: Oblique photographs in which horizon is seen. Tilt is more than 30° & less than 90 °

9. Low oblique High oblique

10. Principle of Aerial survey

11. Definitions

12. Thank you