PS Photogrammetry & Remote Sensing 3

Question 1

The exposure station (perspective center) in aerial photogrammetry is defined as:

Accepted Answer

The spatial position of the camera's front nodal point at the instant of image capture

Answer

A ground control point located at the center of the photo footprint on the ground

Answer

The point on the ground directly beneath the aircraft at nadir

Answer

The focal plane location inside the camera where the image is recorded

Question 2

In stereoscopic photogrammetry, x-parallax measurements are used primarily to:

Accepted Answer

Determine ground elevations from the stereo photo pair

Answer

Measure horizontal planimetric positions of ground features in a photo pair

Answer

Identify camera tilt errors from systematic parallax patterns

Answer

Calculate the camera focal length from image coordinate measurements

Question 3

An Inertial Measurement Unit (IMU) integrated with GPS/GNSS in an airborne photogrammetric system primarily provides:

Accepted Answer

Direct measurement of aircraft roll, pitch, and yaw angles for each photo's exterior orientation

Answer

Radiometric calibration coefficients for the camera sensor between exposures

Answer

Automatic cloud masking to flag obscured portions of each photograph

Answer

Real-time correction of ionospheric signal delay in the GPS observations

Question 4

Sidelap between adjacent aerial flight strips is typically maintained at what percentage for standard mapping projects?

Accepted Answer

20–30%

Answer

5–10%

Answer

50–60%

Answer

70–80%

Question 5

Structure from Motion (SfM) photogrammetry is distinguished from classical photogrammetry primarily by its ability to:

Accepted Answer

Simultaneously reconstruct 3D scene geometry and solve for camera positions from unordered overlapping image sets

Answer

Produce imagery in wavelengths beyond the visible spectrum using consumer cameras

Answer

Operate effectively and produce accurate 3D results from a single high-resolution photograph

Answer

Achieve centimeter-level accuracy without any ground control points under all conditions

Question 6

Multispectral remote sensing enables vegetation health assessment primarily through:

Accepted Answer

Calculation of indices such as NDVI using near-infrared and red band reflectance values

Answer

Its inherently higher spatial resolution compared to standard RGB aerial imagery

Answer

Its faster data acquisition speed compared to panchromatic or hyperspectral sensors

Answer

Its ability to image through cloud cover using microwave energy

Question 7

Radiometric calibration of remote sensing imagery converts raw sensor digital numbers (DN) to:

Accepted Answer

Physically meaningful reflectance or radiance values comparable across different sensors, dates, and atmospheric conditions

Answer

Pixel coordinates in the camera's internal image reference frame

Answer

UTM or State Plane projected ground coordinates for map accuracy

Answer

Classified land-cover categories derived from a supervised classification algorithm