The document provides an overview of photogrammetry, which is the science and technology of obtaining reliable spatial information about physical objects and the environment through analyzing photographs. It discusses the different types of photogrammetry including aerial/spaceborne photogrammetry and close-range photogrammetry. It also summarizes the key techniques, applications, and products of photogrammetry such as digital terrain models, orthophotos, and 3D models.

2. Photogrammetry portrayed as systems approach. The input is usually referred to as data acquisition, the “black box" involves photogrammetric procedures and instruments; the output comprises photogrammetric products.

14. PHOTOGRAMMETRY – Functional Details

15. Types of photographs

17. Overlap Between Runs Not essential but can help 30% overlap between runs or swaths Run #1 Run #2

18. Stereo Vision Left Right Matching correlation windows across scan lines Z ( x , y ) is depth at pixel ( x , y ) d ( x , y ) is disparity baseline depth

21. Stereo aerial photography

23. Digital Cameras The image plane of a digital camera to be used to record spatial objects contains a two dimensional field of sensors. CCD sensors (Change Coupled Devices) predominate in digital photogrammetric cameras. Such cameras are known as CCD Cameras

25. Stereo satellite imagery

28. BRANCHES OF PHOTOGRAMMETRY Analogue Photogrammetry - optical or mechanical instruments were used to reconstruct three-dimensional geometry from two overlapping photographs. The main product during this phase was topographic maps .

34. Example products: maps

35. Example products: DTMs

36. Example products: Virtual landscapes

40. Contour digitizing

41. Contour map

43. Radar mapping from space

44. Stereo radar imagery

45. DEM

46. Stereo photogrammetry

48. LIDAR data Horizontal resolution: 2m Vertical accuracy: ± 2cm

51. DEMs and TINs DEM with sample points TIN based on same sample points

53. DEM Hill shaded DEM Aspect Shaded Aspect Slope Slope draped on DEM DEM derived Variables

54. height slope aspect hillshading plan curvature Feature extraction DEM derived Variables

62. Calculating an inter-visibility matrix Offset b Offset a v v v nv nv nv visible not visible without offset b with offset b