What was the purpose of the stereoscopic lenses in tool 10000 days album

In digital cameras, the scale does not play any role in defining the image quality, as is the case with film-based camera. The following two examples will walk you step by step through the process of computing scales for imagery produced from a film-based camera and from a digital camera. Qassim Abdullah Examples on Scale Computations Scale is expressed either in a unitless ratio such as 1/12,000 (or 1:12,000) or in pronounced units ratio such as 1 in. In Figure 4.4, the distance on the ground AB will be projected on the image on line ab, therefore, the image scale can be computed using the following formula:Д®quation 1: scaleВ = distanceВ ab distanceВ ABДЄnalyzing the two triangles (the small triangle with base ab and the large triangle with base AB) of Figure 4.4, one can also conclude, using the similarity of triangles principle, that the scale is also equal to:Д®quation 2: scaleВ = lensВ focalВ lengthВ (f) FlyingВ heightВ (H) The scale of an image is the ratio of the distance on the image to the corresponding distance on the ground.

Such relations not only enable us to compute the ground coverage of a photograph (image) but also enable us to compute the scale of such a photograph or image. From such geometry, the film four corners a' b' c' d' cover an area on the ground represented by the square ABCD. In Figure 4.3, ground point A is projected at image location a' and ground point B is projected at image location b' on the film. This physical phenomenon enables us to express the ground-image relation using trigonometric principles.

Source: Elements of Photogrammetry with application in GIS, 4th edition, 2014 McGraw Hill Scale of Vertical ImageДЄs the sun's rays hit the ground, they reflect back toward the camera, and some actually enter the camera through the lens. In summary, a vertical image is an image that is either looking straight down to the ground or is looking a few degrees to either side of the aircraft. Therefore, vertical image definition allows a few degrees deviation from the nadir (the line connecting the lens frontal point and the point on the ground that is exactly beneath the aircraft). As the aircraft moves, so does the camera, and this makes it impossible to take a true vertical image. By vertical photograph or image, we mean an image taken with a camera that is looking down at the ground.

oblique photography: between в“5Вє degree and В±55Вє off nadirДЇor the purpose of this course, we will focus only on the first two types, and that is vertical and near-vertical photography.ДЇigure 4.3 illustrates the basic geometry of a vertical photograph or image.

tilted or near-vertical photography > 0Вє but less than в“Вє вЂ“ Most used вЂ“.

true vertical photography: вђВє from nadir.

In photogrammetry, we usually deal with three types of imagery (photography), They are defined in term of the angle that the camera optical axis makes with the vertical (nadir), those are: Therefore, it is essential to the work of the flight planner to have all of this information understood and available before starting to design a mission.

The size of the CCD array and lens focal length coupled with flying altitude (above ground) determines the image scale or the ground resolution of the image. In order to understand mission flight planning, you need to understand the geometry of the image as it is formed within the camera.

What was the purpose of the stereoscopic lenses in tool 10000 days album