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Linear Arrays Along-Track Scanners or Pushbroom Scanners

Multispectral Imaging Using Linear Arrays (Along-Track Scanners or Pushbroom Scanners)

Multispectral Imaging: As previously defined, this involves capturing images using multiple sensors that are sensitive to different wavelengths of electromagnetic radiation.

Linear Array of Detectors (A): This refers to a row of discrete detectors arranged in a straight line. Each detector is responsible for measuring the radiation within a specific wavelength band.

Focal Plane (B): This is the plane where the image is formed by the lens system. It is the location where the detectors are placed to capture the focused image.

Formed by Lens Systems (C): The lens system is responsible for collecting and focusing the incoming radiation onto the focal plane. It acts like a camera lens, creating a sharp image of the scene.

Ground Resolution Cell (D): As previously defined, this is the smallest area on the ground that can be resolved by a remote sensing sensor. In the case of linear array scanners, the ground resolution cell is directly related to the size of the individual detectors and the altitude of the sensor.

How it works:

  1. Radiation Collection: The lens system collects and focuses the incoming radiation onto the linear array of detectors.
  2. Spectral Separation: Each detector measures the radiation within its specific wavelength band, capturing information about different materials and features.
  3. Scanning: As the sensor moves forward, the linear array of detectors continuously scans the scene, capturing data from different points along the track.
  4. Data Processing: The collected data is processed to create multispectral images that can be analyzed to identify and classify features based on their spectral signatures.

Key advantages of this approach:

  • High spatial resolution: Can capture detailed images of the Earth's surface.
  • Continuous data acquisition: Can collect data continuously as the sensor moves, providing a high data rate.
  • Efficient use of detectors: All detectors are used simultaneously, maximizing data collection efficiency.
  • Wide swath coverage: Can cover a wide area on the ground as the sensor moves forward.

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