## What is principal point in remote sensing?

The point on the earth where a satellite sensor is focused at any time during its orbit. If the sensor vertical axis is perpendicular to the earth’s surface, the principal point coincides with the subpoint. A term used in remote sensing; the point where the optical axis intersects the principal plane.

How do you read an aerial photograph?

Interpretation of Aerial Photographs

1. Tone/hue — lightness/darkness of an object, or color if it’s a color or CIR photo.
2. Texture — coarse or fine, such as in a corn field (distinct rows) vs.
3. Shape — square, circular, irregular.
4. Size — small to large, especially compared to other known objects.

### What is geometry of aerial photograph?

The geometry of an aerial photograph is based on the simple, fundamental condition of collinearity. By definition, three or more points that lie on the same line are said to be collinear. The length of each ray, from the focal point to the photographic image, is fixed by the focal length of the lens.

What is the principal point?

The principal point is the point on the image plane onto which the perspective center is projected. It is also the point from which the focal length of the lens is measured. This is defined as the image position where the optical axis intersects the image plane.

#### What is principal point offset?

The “principal point offset” is the location of the principal point relative to the film’s origin. The exact definition depends on which convention is used for the location of the origin; the illustration below assumes it’s at the bottom-left of the film.

How do I interpret a photograph?

1. The main subject is what the photographer wanted the audience to see.
2. The composition is how the photographer wanted the audience to feel about the main subject.
3. The minor subjects may indicate how the photographer wanted the audience to react to what they see.

## What are the two types of aerial photographs?

aerial photographs are classified into the following types : (i) Vertical photographs (ii) Low oblique photographs (iii) High oblique photographs (i) Vertical Photographs: While taking aerial photographs, two distinct axes are formed from the camera lens centre, one towards the ground plane and the other towards the …

What is the difference between map and photograph?

The big difference between a photograph and a map is that a map represents a vertical “plan” of a region, while a photograph presents a realistic image. Such photographs are taken vertically, i.e. by means of a camera that is attached to a special aeroplane in such a way that it points down towards the earth.

What is principal point in remote sensing? The point on the earth where a satellite sensor is focused at any time during its orbit. If the sensor vertical axis is perpendicular to the earth’s surface, the principal point coincides with the subpoint. A term used in remote sensing; the point where the optical axis intersects…