مرجع دانلود پاورپوینت های درسی

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نوع فایل : پاور پوینت
تعداد اسلاید ها : 46
بنام خدا 1 2 فصل 7 : مشخصات و هندسه عکس قائم 45 Slide 3 Definitions Vertical photograph – photo taken with the optical axis coinciding with the direction of gravity
Tilted photograph – photo taken with the optical axis unintentionally tilted from the vertical by a small amount, usually less that 3°
Near vertical photo
Exposure station – space position of the front nodal point at the instant of exposure
Flying height – elevation of exposure station above sea level or datum 4 DEFINITIONS (cont.) x-axis of the photograph – line on photo between opposite fiducials which most nearly parallels the direction of flight
y-axis – line on photo normal to x-axis with positive being 90° counter-clockwise from +x 5 Coordinate System Using Corner FIDUCIALS x’, y’ coordinates – arbitrary


where

6 Scale Over Flat Terrain Utilizing similar triangles
7 SCALE OVER FLAT TERRAIN (Example) Example: Vertical photo taken over flat terrain with 152.4 mm focal length camera at a height of 1830 m above ground. What is the photo scale?
Solution: 8 SCALE OVER VARIABLE TERRAIN 9 SCALE OVER VARIABLE TERRAIN (cont.) By similar triangles, Loa and LAOA:

By similar triangles LOAA and Loa


Scale is: 10 Average Scale Defines overall mean scale of vertical photo over variable terrain


where:
11 SCALE OVER VARIABLE TERRAIN (Example) Example: The highest, average, and lowest terrain points are 610, 460, and 310 m above sea level respectively. Calculate the maximum scale, minimum scale, and average scale if the flying height above mean sea level is 3000 m and the camera focal length is 152.4 mm. 12 SCALE OVER VARIABLE TERRAIN Solution:
Maximum scale:

Minimum scale:

Average scale:
13 SCALE OVER VARIABLE TERRAIN How to determine scale if the area on the photography is inaccessible?
If map of area is available, it can be used to help determine scale
Use relationship
14 SCALE OVER VARIABLE TERRAIN (Example) Example: The length of an airport runway measures 160 mm on a vertical photograph. On a map, whose scale is 1:24,000, the runway scales 103 mm. What is the scale of the photograph at the runway elevation
Solution:
15 GROUND COORDINATES FROM VERTICAL PHOTO 16 GROUND COORDINATES FROM VERTICAL PHOTO (cont.) From similar triangles La’o and LA’AO







From similar triangles La”o and LA”AO<b...