Satellite Imagery and Environmental Monitoring

Nature and Collection of Satellite Images

  • Satellites are human-made objects orbiting Earth, equipped with remote sensors to collect data on environmental resources.

  • Remote sensors act as sophisticated scanners, observing radiation across seven spectral bands ranging from visible to thermal infrared regions.

  • Scanning is possible because the atmosphere is transparent to certain radiation types in specific parts of the electromagnetic spectrum, known as atmospheric windows or channels.

  • Data is transmitted to computers on Earth, where scientists enhance the images to study terrain objects and environmental processes.

High-Resolution Satellite Image Types

  • Visible satellite images: Used for tracking systems like Tropical Storm Alex (observed June 29th, 2010).

  • Infrared satellite imagery: Used for data such as global CO2CO_2 levels (recorded by a Nasa satellite in July 2009).

  • Water vapor satellite imagery: Used to visualize moisture in the atmosphere (recorded September 14th, 2012).

Applications of Satellite Data

  • Monitoring large-scale environmental changes, including deforestation, pollution distributions, and regional impacts.

  • Facilitating accurate weather forecasting and the routing of storms.

  • Assessing damage from natural disasters such as earthquakes or volcanoes and monitoring the rehabilitation of burned or deforested areas.

  • Analyzing the relationship between ocean surface temperature changes, rainfall patterns, droughts, and urban or rural flooding.

Questions & Discussion

  • Activity 12: Look at Figure 1.26 and answer the following questions:

    • Question: Why can't we see North America or India on this satellite image?

    • Question: What is shown by the blue, brown and white areas?

  • Diagram Exercise Information (dated 29 January 2026):

    • Earth's diameter: 12800km12\,800\,km

    • Weather satellite's distance from Earth: 36000km36\,000\,km

    • Size of weather satellite: 3m×3m3\,m \times 3\,m

    • Position: The satellite remains stationary over West Africa.