What are the disadvantages of the optical sensors?

Correct Answer : Option (B) :   Weather must be favorable

Explanation : The optical sensors are very accurate in determining the satellite. For taking a good photo, there are some conditions that have to be followed- good weather conditions, correct lighting and the satellite must be in the sunlight.

Correct Answer : Option (C) :   Radio interferometer

Explanation : Radio interferometers are sensors which accurately measure the directional information of a satellite using radio interferometry. It makes use of 2 or more antennas of high aperture and waves interferes on the same receiver. This is similar to the double- slit experiment phenomenon.

Correct Answer : Option (D) :   Over- the- horizon radar

Explanation : OTH radar operates on the principle of detecting launches and identifying the signature of a particular booster by the disturbance it causes in the ionosphere.