RS stands for Remote Sensing. What is it?

• A. Ground surveys only
• B. A map symbol set
• C. A type of GPS
• D. Detecting and monitoring physical characteristics of an area without making physical contact with the area through remote sensors, usually from satellites or aircraft

Answer: (D)

Remote sensing means detecting and monitoring physical characteristics of an area without making physical contact, usually from sensors on satellites or aircraft. These sensors measure energy reflected or emitted by the surface across different wavelengths, letting us infer things like land cover, vegetation health, temperature, moisture, and texture over large areas. This approach enables repeated observations over time to track changes such as drought, urban growth, or floods. Ground surveys require being on site, map symbol sets are conventions for depicting features on maps, and GPS focuses on determining precise location, not assessing area-wide characteristics from a distance.