Which one of the following parameters is accurate for DGPS ?

A. Positional accuracies ~ 1 – 2 m if rover is less than 1-2 km from the reference station
B. Positional accuracies ~ 2 – 5m if rover is less than 2-5 fm from the reference station
C. Positional accuracies ~ 5 – 10 m if rover is less than 5-10 km from reference station
D. Positional accuracies ~ 5 – 10 m if rover is less than 25 km

The interaction of the electromagnetic radiation produced with a specific wave length to illuminate a target on the terrain for studying its scattered radiance, is called____________________?

A. Passive remote sensing
B. Active remote sensing
C. Neutral remote sensing
D. None of these

The refractive index of the ocean water_______________?

A. Increases with salinity
B. Increases with temperature
C. Decreases with salinity
D. Decreases with temperature

The spectral region of the electromagnetic radiation which passes through the atmosphere without much attenuation is known as__________________?

A. Ozone hole
D. None of these

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

A. Sensors
B. Passive sensors
C. Active sensors
D. None of these

Orbital radius of GPS satellites is approximately ___________________?

A. 15,200 km
B. 26,600 km
C. 18,400 km
D. 36,000 km

“An Electromagnetic wave falls on to a boundary between two losses less homogeneous media with different refractive indices, a part of the wave is reflected back to the incident medium and the rest is transmitted on to the second media”. This phenomenon is known as___________________?

A. Fresnel reflection
B. Fresnel refraction
C. Snell’s law
D. None of these

Who coined the term, ‘Remote sensing_______________?

A. Evelyn l. pruitt, a geographer
B. Gaspard felix tournachon, a french scientist
C. Wilbur wright, an italian scientist
D. None of these

A passive sensor uses ________________?

A. Sun as the source of energy
B. Flash light as a source of energ
C. Its own source of energy
D. None of these

The basic requirement of any sensor system is___________________?

A. Radiometric resolution
B. Spatial resolution
C. Spectral resolution
D. All of these