OE-6.3 Microwave Remote Sensing & LiDAR

Work through these

• Active and passive microwave remote sensing

  Instruments that supply their own energy, and the two kinds. Providing your own illumination is what makes this family work through cloud and at night.

• Key components of imaging radar; viewing geometry

  What an imaging radar is made of, and why the geometry matters so much. Side-looking is not an accident: an instrument pointing straight down could not tell left from right.

• Spatial resolution in radar imaging

  How fine a detail this kind of instrument can separate, in two directions that behave differently. The along-and-across asymmetry here is what motivates the next two items.

• Principle of real aperture radar (RAR) and its range resolution

  The straightforward approach, where resolution is set by the physical size of the antenna. It gives the number that shows why the next item had to be invented.

• Principle of synthetic aperture radar (SAR) and its range resolution

  Using the platform's own motion to synthesise a much larger antenna. It is the central idea of modern radar imaging and the reason spaceborne radar is useful at all.

• Satellite radar imaging

  What is actually flying, and what the images look like. It connects the theory above to data you could obtain.

• LiDAR

  The same idea with light instead of radio, giving height directly. It is the standard way to make a terrain model, and it feeds straight into the surface analysis later in this course.