Certified Photogrammetrist Camera Calibration & Sensor Geometry 2

Question 1

What causes decentering (tangential) lens distortion?

Accepted Answer

Misalignment of optical elements from the optical axis within the lens system

Answer

Curvature mismatch of the lens elements

Answer

Temperature variations during flight operations

Answer

Atmospheric refraction of light rays

Question 2

What is the purpose of a reseau grid (reseau plate) in analog aerial cameras?

Accepted Answer

To provide reference marks for detecting and correcting film deformation

Answer

To filter ultraviolet radiation from sunlight

Answer

To improve image sharpness at the corners of the frame

Answer

To record the exact time of each exposure

Question 3

In digital aerial cameras, what component replaces the photographic film at the focal plane?

Accepted Answer

The CCD or CMOS image sensor

Answer

The lens system

Answer

The shutter mechanism

Answer

The viewfinder assembly

Question 4

In digital photogrammetry, pixel size of the sensor is most directly related to:

Accepted Answer

The ground sample distance (GSD)

Answer

The focal length of the camera lens

Answer

The shutter speed setting

Answer

The lens radial distortion magnitude

Question 5

Which camera calibration parameter corrects for non-orthogonality (shear) between the x and y axes of the image coordinate system?

Accepted Answer

Affinity (shear) parameter

Answer

Radial distortion coefficient K1

Answer

Principal point offset

Answer

Focal length correction

Question 6

The Modulation Transfer Function (MTF) in optical and sensor systems is used to measure:

Accepted Answer

The ability of the system to resolve and transfer spatial frequency detail

Answer

The accuracy of onboard GPS position measurements

Answer

The radial lens distortion profile

Answer

The sensor dark current noise level

Question 7

A camera with a 150 mm focal length is flown at 3,000 m above ground level. What is the approximate nominal image scale?

Accepted Answer

1:20,000

Answer

1:200

Answer

1:2,000

Answer

1:200,000