Optics

Given:


We know:

Timing error in meters:

Now convert distance into time using speed of light:

Across-track scanners scan perpendicular to the flight path. Therefore, relief displacement is across the track, not along it. So, (A) is incorrect and (B) is correct.
As distance from nadir increases, image scale compression increases — hence, (C) is false.
Linear features captured by across-track scanners often appear curved or sigmoidal due to geometric distortions inherent in scanning — making (D) correct.

Final Answer:

Given:
We know:
Timing error in meters:
Now convert distance into time using the speed of light:

White-sky albedo refers to the albedo calculated under the assumption of uniform diffuse illumination, such as from an overcast sky.
In this case, the incoming radiation is assumed to be isotropic, meaning it comes equally from all directions in the hemisphere above the surface.

To compute white-sky albedo, reflectance is integrated over all incoming directions in the upper hemisphere (diffuse illumination),
and the reflected radiation is also integrated over the entire hemisphere above the surface.
This corresponds to a bi-hemispherical reflectance geometry, where both the incoming and outgoing hemispheres are considered in the calculation.