Question 42 from UPSC CSE 2024 - S&T

Question

Consider the following activities:
1. Identification of narcotics on passengers at airports or in aircraft
2. Monitoring of precipitation
3. Tracking the migration of animals
In how many of the above activities can radars be used?

IASCODEX · Accepted Answer

Correct Option: B. Only two

Strategy: Match each activity with typical radar applications. Radar is well-known for weather monitoring (activity 2) and is used in ecological research for tracking animals and birds (activity 3). For airport narcotics identification (activity 1), standard procedures involve X-ray or millimeter-wave scanners, not radar. Radar's resolution is inadequate for reliably identifying substances in luggage or on persons. Therefore, exclude activity 1 and include activities 2 and 3, resulting in 'Only two' valid uses.

Key Info: Radar (Radio Detection and Ranging) is a remote sensing technology that transmits radio waves and measures their reflection from objects, thereby detecting, locating, and tracking moving or stationary targets.

Its primary applications include:

*   **Weather Monitoring:** Doppler and other weather radars provide real-time information on precipitation, storm structure, rainfall intensity, and movement, critical for meteorology and disaster management.
*   **Animal Migration Studies:** Radar is widely used to track the altitude, speed, and direction of migrating animals, including birds, bats, and even large insects, allowing large-scale studies irrespective of visibility conditions.
*   **Airport Security:** Passenger screening at airports typically employs X-ray scanners for baggage and millimeter-wave scanners or backscatter equipment for personnel. These are not conventional radar systems. Radar itself, which focuses more on reflecting surfaces and movement rather than compositional detection, is not apt for detecting specific narcotics or illicit substances in luggage or on persons.
*   **Additional Context:** Millimeter-wave radar at airports may be used for surface movement control or foreign object debris detection on runways, distinguishing it from body or baggage scanning.
*   **Limitations:** Radar is not suited for direct chemical composition analysis or identification of specific illicit substances due to its comparatively low spatial and material discrimination, unlike X-rays or advanced spectroscopic technologies.
*   **Examples of Institutions:** The India Meteorological Department (IMD) uses Doppler weather radars extensively. Ornithological studies in India and globally harness radar for migration monitoring.

While radars are foundational in atmospheric and ecological research, standard airport narcotic detection relies on distinct imaging or scanning modalities.

IASCODEX · Answer

Option A: Only one

IASCODEX · Answer

Option C: All three

IASCODEX · Answer

Option D: None

Consider the following activities: Identification of narcotics on passengers at airports or in aircraft Monitoring of precipitation Tracking the migration of animals In how many of the above activities can radars be used?

Consider the following activities:

Identification of narcotics on passengers at airports or in aircraft

Monitoring of precipitation

Tracking the migration of animals
In how many of the above activities can radars be used?