#### Elements of Remote Sensing

21

The remote sensing techniques applied for the earth's surface features, is generally confined to the following wave lengths :

A. 0.4 to 1.3, 1.5 to 1.8, 2.2 to 2.6mu m
B. 2.2 to 2.6, 3.0 to 3.6, 4.2 to 5.0 mum
C. 4.2 to 5.0, 7.0 to 15.0 mum and 1 cm to 30 cm
D. All of these

22

Rayleigh's criteria for a rough surface is: (where letters carry their usual meanings).

A. h > lambda // Delta cos theta
B. h = lambda // 8 cos theta
C. h > lambda // 8 cos theta
D. h < lambda // 8 cos theta

23

If 0 is the angle of scan measured from the nadir, the ground distance swept by the sensor IFOV is proportional to :

A. sin^2 theta
B. cos^2 theta
C. sec^2 theta
D. tan^2 theta

24

Assuming n as the frequency of radiation, n0 as the threshold frequency and k as a constant, the energy of the photo-electrons (E) is related as

A. E = k (n - n0)
B. E = k (n + n0)
C. E = k (n x n0)
D. E = frac(k)(2) (n+n0)

25

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

A. The nominal altitude is about 20, 200 km
B. The inclination of axis satellite is 55Â°
C. The satellite transmits two L band signals (L1 with 1575.42 MHz and L2 with 1276.6 MHz)
D. All of these