Elements of Remote Sensing MCQs

Question 1

Earth observations from a satellite platform provide:

Accepted Answer

All of these

Answer

Synoptic view of a large area

Answer

Constant solar zenith angles and similar illumination conditions

Answer

Repetitive observations of the same area with intervals of a few minutes to a few weeks

Question 2

The instruments which provide electromagnetic radiation of specified wave length or a band of wave lengths to illuminate the earth surface are called:

Accepted Answer

Active sensors

Answer

Sensors

Answer

Passive sensors

Answer

None of these

Question 3

Pick up the correct statement from the following

Accepted Answer

All of these

Answer

The ratio of the up flux and down flux just above the snow surface, is called albedo

Answer

Spectral albedo of snow is calculated for the semi-infinite snow thickness

Answer

Water equivalent height of snow is the height of water column obtained by melting snow

Question 4

Consider the following statements regarding the satellite imaging: 1. The satellite orbit is fixed in the inertial space 2. During successive across-track imaging, the earth rotates beneath the sensor 3. The satellite images a skewed areaWhich one of the following statements is/are correct?

Accepted Answer

1, 2, 3

Answer

1, 3

Answer

2, 3

Answer

1, 2

Question 5

Due to scan geometry of a satellite sensor:

Accepted Answer

All of these

Answer

The off-nadir resolution is degraded

Answer

The ground distance swept by the senor, IFOV is proportional to sec2θ, where θ is the angle of scan measured from the nadir

Answer

The details towards the edge of the scan get compressed

Question 6

Coherence of two electromagnetic waves takes place if their phase difference is:

Accepted Answer

Constant in time and space

Answer

Constant in time

Answer

Constant in space

Answer

None of these

Question 7

The basic requirement of any sensor system is:

Accepted Answer

All of these

Answer

Radiometric resolution

Answer

Spatial resolution

Answer

Spectral resolution

Question 8

A passive sensor uses:

Accepted Answer

Sun as the source of energy

Answer

Flash light as a source of energy

Answer

Its own source of energy

Answer

None of these

Question 9

DGPS is based on the concept that bias errors in the position of locations in a given local area, are same if their distances are within

Accepted Answer

100 km

Answer

25 km

Answer

50 km

Answer

75 km