Elements of Remote Sensing MCQs

Question 1

Due to perturbation of the orbit, satellite orbit parameters are frequently updated on measurements carried out by its

Accepted Answer

Five ground stations

Answer

Six ground stations

Answer

Four ground stations

Answer

Three ground stations

Question 2

The normal altitude of GPS satellite is about

Accepted Answer

20,200 km

Answer

16,200 km

Answer

24,400 km

Answer

36,100 km

Question 3

The ratio of the total solar radiant energy returned by a planetary body to the total radiant energy incident on the body, the called:

Accepted Answer

Albedo

Answer

Reflectance

Answer

Reflectance factor

Answer

None of these

Question 4

Which one of the following parameters is accurate for DGPS?

Accepted Answer

Positional accuracies ~ 1 - 2 m if rover is less than 1-2 km from the reference station

Answer

Positional accuracies ~ 2 - 5 m if rover is less than 2-5 km from the reference station

Answer

Positional accuracies ~ 5 - 10 m if rover is less than 5-10 km from reference station

Answer

Positional accuracies ~ 5 - 10 m if rover is less than 25 km

Question 5

Which one of the following errors is produced by platform characteristics of the sensor?

Accepted Answer

All of these

Answer

Altitude variation

Answer

Altitude

Answer

Orbit drift

Question 6

If electric permittivity and magnetic permeability of the medium are respectively $$\varepsilon $$ and $$\mu $$, then the velocity (Cm) of the electromagnetic wave in the medium is given by:

Accepted Answer

$${{	ext{C}}_{	ext{m}}} = \frac{1}{{\sqrt 8 \mu }}$$

Answer

$${{	ext{C}}_{	ext{m}}} = \frac{1}{{\varepsilon \mu }}$$

Answer

$${{	ext{C}}_{	ext{m}}} = \frac{5}{{\sqrt \varepsilon \mu }}$$

Answer

None of these

Question 7

The altitudinal distance of a geostationary satellite from the earth is about:

Accepted Answer

36,000 km

Answer

26,000 km

Answer

30,000 km

Answer

44,000 km

Question 8

Which one of the following statements is correct regarding the GPS satellites?

Accepted Answer

All of these

Answer

The nominal altitude is about 20,200 km

Answer

The inclination of axis satellite is 55°

Answer

The satellite transmits two L band signals (L1 with 1575.42 MHz and L2 with 1276.6 MHz)

Question 9

For C band Synthetic Aperture Radar (SAR) with Doppler band width of 1300 Hz, the coherence length loch is:

Accepted Answer

230 km

Answer

130 km

Answer

250 km

Answer

500 km