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Difficulty: EasyGIS and Remote Sensing Fundamentals

In satellite remote sensing, sensors are categorized based on their energy source. Which type of sensor generates its own electromagnetic energy to illuminate a target and measure the backscattered signal?

  1. Active sensorAnswer
  2. B
    Passive sensor
  3. C
    Attribute table sensor
  4. D
    Vector digitizing sensor

Answer

An active sensor is a remote sensing instrument that emits its own energy source to illuminate a surface and detect the reflected radiation.
The correct option is the active sensor because active remote sensing instruments transmit artificial pulses of electromagnetic radiation toward a target on Earth and record the echo or reflected signal.

Step-by-Step Solution

1
Identify the energy mechanism in remote sensing systems.
Sensors are classified into two major operational modes: active systems (self-illuminating) and passive systems (solar radiation dependent).
Remote sensing classification depends on whether the system relies on internal or external energy emission.
2
Evaluate the definition of self-emitting systems.
Sensors such as Radar (Radio Detection and Ranging) and LiDAR (Light Detection and Ranging) send out pulses of electromagnetic energy and record the signal returned.
By generating their own energy, active sensors can operate day or night and penetrate cloud cover.

Key Concept

Active vs. Passive Remote Sensing Systems
Estimated Time:45s
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Topics

GIS and Remote Sensing Fundamentals

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