Lecture

Interactions with Surface and Atmosphere: Remote Sensing Principles

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Description

This lecture covers the interactions between electromagnetic radiation (EMR) and the Earth's surface and atmosphere, focusing on the principles of remote sensing. It begins with the concepts of refraction and reflection, including Snell's law and Brewster's angle, which describe how light behaves at the interface of different media. The lecture then discusses the energy balance of solar radiation absorbed and reflected by the atmosphere and surface, emphasizing the importance of thermal inertia in understanding temperature variations. The instructor explains how different surfaces, such as water and soil, respond to solar radiation, highlighting the role of moisture content in thermal properties. The lecture also introduces microwave remote sensing, detailing how it can effectively measure soil moisture due to the distinct dielectric constants of water and soil. Finally, the lecture outlines the various platforms for remote sensing, including terrestrial, aerial, and satellite systems, and discusses the significance of atmospheric windows for effective data collection.

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Related concepts (32)

Reflection (physics)

Reflection is the change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated. Common examples include the reflection of light, sound and water waves. The law of reflection says that for specular reflection (for example at a mirror) the angle at which the wave is incident on the surface equals the angle at which it is reflected. In acoustics, reflection causes echoes and is used in sonar. In geology, it is important in the study of seismic waves.

Specular reflection

Specular reflection, or regular reflection, is the mirror-like reflection of waves, such as light, from a surface. The law of reflection states that a reflected ray of light emerges from the reflecting surface at the same angle to the surface normal as the incident ray, but on the opposing side of the surface normal in the plane formed by the incident and reflected rays. This behavior was first described by Hero of Alexandria (AD c. 10–70). Later, Alhazen gave a complete statement of the law of reflection.

Data collection

Data collection or data gathering is the process of gathering and measuring information on targeted variables in an established system, which then enables one to answer relevant questions and evaluate outcomes. Data collection is a research component in all study fields, including physical and social sciences, humanities, and business. While methods vary by discipline, the emphasis on ensuring accurate and honest collection remains the same.

Radiation pressure

Radiation pressure (also known as light pressure) is the mechanical pressure exerted upon any surface due to the exchange of momentum between the object and the electromagnetic field. This includes the momentum of light or electromagnetic radiation of any wavelength that is absorbed, reflected, or otherwise emitted (e.g. black-body radiation) by matter on any scale (from macroscopic objects to dust particles to gas molecules). The associated force is called the radiation pressure force, or sometimes just the force of light.

Fresnel equations

The Fresnel equations (or Fresnel coefficients) describe the reflection and transmission of light (or electromagnetic radiation in general) when incident on an interface between different optical media. They were deduced by Augustin-Jean Fresnel (freɪˈnɛl) who was the first to understand that light is a transverse wave, even though no one realized that the "vibrations" of the wave were electric and magnetic fields.

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