How does the electromagnetic spectrum play a role in remote sensing particularly for environmental monitoring?

In remote sensing, the electromagnetic spectrum is crucial for capturing data about the Earth's surface and atmosphere. Sensors onboard remote sensing platforms detect reflected or emitted electromagnetic radiation from objects or areas of interest. For environmental monitoring, different bands of the spectrum provide varied information. Visible wavelengths can be used to monitor chlorophyll content in vegetation, infrared bands are helpful in assessing vegetation health and water boundaries, and thermal bands are used to measure surface temperatures. Moreover, microwave radiation, which can penetrate clouds, is useful for monitoring precipitation, soil moisture, and sea ice movements.

Examples:

• Satellite imagery taken in the visible bands can help monitor deforestation and changes in land cover.
• Infrared sensors are widely used to assess plant health through the Normalized Difference Vegetation Index (NDVI).
• Thermal sensors are employed in detecting hotspots for wildfire management.

References:

• NASA Earth Data - Remote Sensing
• USGS - Band Designations for Landsat Satellites