Elements Of Remote Sensing
Critical angle of electromagnetic radiation takes place if

Angle of incidence is greater than the angle of refraction
Angle of incidence is equal to angle of refraction
Angle of incidence is equal to 90°
Angle of refraction is equal to 90°

ANSWER DOWNLOAD EXAMIANS APP

Elements Of Remote Sensing
Earth observations from a satellite platform provide:

Repetitive observations of the same area with intervals of a few minutes to a few weeks
Constant solar zenith angles and similar illumination conditions
All of these
Synoptic view of a large area

ANSWER DOWNLOAD EXAMIANS APP