The Physics Behind Remote Sensing

The Physics Behind Remote Sensing

Length: 1142 words (3.3 double-spaced pages)

Rating: Excellent

Open Document

Essay Preview

More ↓
Remote Sensing is the science of acquiring, processing and interpreting images that record the interaction between the electromagnetic energy and matter (Sabins, 1997). Remote sensing offers extensive applications in almost every area of science from monitoring forest fires to geologic mapping . Although many aspects of remote sensing are complex and difficult to understand the basic theory behind remote sensing is simple physics.

There are four major stages of remote sensing. The first stage is the source of energy, usually the sun, which sends energy to a target. The second stage is the interactions that the energy will go through as it passes through a vacuum and the earth’s atmosphere. There is then interactions that occurs with the body on earth’s surface. The energy again, goes through the atmosphere and finally the sensor is able to detect and record the electromagnetic energy.

Electromagnetic Energy

Electromagnetic energy is a dynamic form of energy that is caused by the acceleration or oscillation of a charged particle. All substances above absolute zero (0 Kelvin) emit a range of electromagnetic energy. The sun emits electromagnetic energy and practically all of the natural electromagnetic energy injected into the earth is produced by the sun (Prakush, 2002).

Electromagnetic Radiation

Electromagnetic Radiation is the streams of mass-less particles, traveling in a harmonic, sinusoidal fusion at the velocity of light each possessing a specific amount of energy. The distance from one peak to the next is the wavelength and the number of peaks passing through a fixed point per unit time is the wave frequency (Lillesand and Kiefer, 1994). Electromagnetic radiation is Electromagnetic energy in motion and can be described by the basic wave theory.

Electromagnetic Spectrum

Electromagnetic waves are characterized by their wavelength location within the electromagnetic spectrum which is most commonly measured in micrometers. Names are often assigned to regions of the electromagnetic spectrum, but there is no clear cut dividing lines from one region to the next (Lillesand and Kiefer, 1994).

Stefan - Boltzmann Law

How much energy any objects radiates is a function of its surface temperature.

The Stefan - Boltzmann equations tells one that as a temperature of a body increase the total radiance of the body will also increase. (Sabins, 1997).


The way electromagnetic radation interacts with matter can be detected with different sensors. How the radation interacts depends upon the properties of the medium, the wavelength of the incedent radation and the incident angle. There are four major types of interactions that occur: transmission, reflection, scattering and absorption (Lillesand and Kiefer, 1994).

How to Cite this Page

MLA Citation:
"The Physics Behind Remote Sensing." 14 Dec 2019

Need Writing Help?

Get feedback on grammar, clarity, concision and logic instantly.

Check your paper »

Importance of Remote Sensing in the Study of Climate Change Essay

- Climate change is one of the most prominent problems facing mankind in the 21st century and remote sensing through space based observation has come to play a more and more important role in the study of climate change since its inception (Cracknell and Varatsos, 2011; Navalgund and Singh, 2011.). Cracknell and Varatsos (2011) says there are two reasons as to why remote sensing plays a vital role in the study of climate change, namely the huge coverage the data provides in terms area which allows studies at a local, regional or global scale and also the temporal coverage of this data as there are now libraries of data covering several decades available....   [tags: Remote Sensing, Modern Dilemmas]

Research Papers
1370 words (3.9 pages)

Remote Sensing in Afghanistan Essay

- The United States up until the early 90’s spent all it military resources preparing to fight the evil empire of the Soviet Union. These potential enemies dominated not only the tactics and weapon system of its days but also the remote sensors designed for this enemy. The United States created multiple Intelligence, Reconnaissance, and Surveillance (ISR) platforms, most of which were designed and used to monitor the behemoth Cold War forces of the former Soviet Union. With these impressive sensors analysts far from the fight could track where their missiles, ships, planes, and tanks were at all times....   [tags: War, intelligence, surveilance]

Research Papers
1899 words (5.4 pages)

Remote Sensing Essay

- Remote Sensing Audience #1 is a group of high school students being introduced to the term for the first time. Have you ever seen the film Enemy of the State. How about The Bourne Identity, or any recent James Bond movie. All of these movies have something in common: they use striking graphics in the form of maps or satellite pictures – all the product of remote sensing. Remote sensing is a method by which scientists gather information about the surface of the earth from a distance. Remote Sensing can be traced back as far as the 1860s, and has since developed into the primary method of data gathering from the earth’s surface....   [tags: Mapping]

Research Papers
1581 words (4.5 pages)

Applications Of Remote Sensing Using Machine Learning Essays

- Applications of remote sensing using machine learning: Remote sensing of water: As water is very precious and important in the earths ecosystem it is important to study about the water. With the use of remotely sensing methods oceanographer, other environmental and marine researchers studying all the effects through examining the big areas. Images clicked by the satellites of NASA are used to remote sense the ocean to find out the chlorophyll levels and surface temperature, these images are also useful for the costal mapping and lake remote sensing....   [tags: Water, Oxygen, Machine learning, Ocean]

Research Papers
1201 words (3.4 pages)

Essay on The Role of GIS and Remote Sensing in Environmental Impact Assessment

- QUESTION What is the role of GIS and Remote Sensing in 1. Environmental Impact Assessment 2. Substance Flow Analysis 3. Carbon Foot printing 4. Health Impact Assessment 5. Social Impact Assessment Introduction Geospatial techniques such as Geographic Information Systems (GIS) and remote sensing play a pivotal role in Environmental Impact Assessments (EIAs) and their various components such as ecological, social and hydrological impact assessment. These tools have proved so useful that they have also been incorporated into carbon foot printing and substance flow analysis....   [tags: Carbon Footprinting, Spacetime Methods]

Research Papers
2455 words (7 pages)

Applied Uses of Remote Sensing In Forestry and Forest Management Essay

- Remote Sensing is a technology that can offer data and information across an extremely broad range of topics, making it an invaluable tool to researchers, scientists, and many people across the world today. One such invaluable use of remote sensing is in the application of forestry. In the past, scientists used to collect data on the ground from a relatively small section of a forest, and assume that their data would be an accurate representation of the forest as a whole. Today, studying forests hands-on is mostly done as ground truthing for data originally collected by remote sensing....   [tags: Severe Deforestation, Infected Trees]

Research Papers
2569 words (7.3 pages)

Remote Sensing, Land Use, Land Cover Essay

- INTRODUCTION Remote sensing can be applied to many fields like plant sciences, Earth sciences, hydrospheric sciences, and observing land use/land cover. In deciding which of the four fields that is the most pivotal, when they are all somewhat equal in their necessity of understanding, it would have to be the observation of land use and land cover. Aside from the weather being one of the most desirable items for remote sensors and people to observe, it it more fitting to observe human activity and the land under domain....   [tags: hydrospheric, earth, plant sciences]

Research Papers
1966 words (5.6 pages)

The Physics Behind the Power of an Engine Essay

- The Physics Behind the Power of an Engine Insert the key, turn, and vroom. And down the road you go. Most people take for granted the strange conglomeration of metal and plastic under that sheet of metal either in front or back of their vehicle. The engine as you may have guessed, is modern marvel- so to speak. They’re found in cars, trucks, boats, airplanes…All with various power outputs. To discuss the power output, first the cycles of the engine itself needs to be mentioned. 1.Intake: The intake valve opens allowing fresh oxygen rich air mixed with fuel to enter the cylinder....   [tags: Physics Engine Essays]

Free Essays
1646 words (4.7 pages)

Physics Behind Why Rockets Fly Essay

- In order for any rocket to fly, it must obey some basic rules of physics. No rocket can escape the cardinal rule that the center of gravity must be in front of the center of pressure. Center of Gravity The Center of Gravity or Cg is the point that behaves as if all the mass was concentrated in that one spot. Simply put it is the point at which you could balance the rocket on your finger. The Cg is also the point around which the rocket rotates. This becomes very important for the rocket's stability as you will soon see....   [tags: physics rocket rockets fly]

Free Essays
511 words (1.5 pages)

The Physics Behind Parking Essay

- Background: After a long day of cruising through town with your buddy, the two of you have grown quite an appetite. You spot a McDonalds at the top of a very steep hill. Unfornately a local biker gang must of had the same idea. Encredibly, the only available parking spot is on the street, uphill of nearly 15 Harleys. There are no other restaurants for 100 miles in all directions. Famished, your friend skillfully manuvers his car to the side of the road. The breaks shudder as the car comes to a stop on the hill....   [tags: physics science cars vehicles]

Free Essays
1403 words (4 pages)

The atmosphere also has interactions with electromagnetic radiation as it passes through the atmosphere. Atmospheric scattering occurs when electromagnetic radiation entering the atmosphere interacts with particles in the atmosphere and the direction of the energy change is not predictable (Prakash, 2002). There are three major types of atmospheric scattering which are dependent on the wavelength of radiation and the size of the atmospheric particles.
Rayleigh scattering is the most common type of scattering and occurs when the electromagnetic radiation is much larger than the particles in the atmosphere. Rayleigh scattering occurs in the blue section of the electromagnetic spectrum and is the reason that the sky appears blue (Prakash, 2002).
Mie Scattering occurs when the wavelength of the incoming electromagnetic radiation is comparable in size to the atmospheric particle. Mie scattering occurs in the red and orange parts of the spectrum and explains why the sky appears orange and red at dusk and dawn. The water vapor and fumes in the atmosphere cause the electromagnetic radiation to scatter(Prakash, 2002).
Non- Selective Scattering occurs when the wavelength is smaller than the particles in the atmosphere. Non-selective scattering affects all of the parts of the spectrum equally and explains why clouds appear white. White clouds are a result of all of the visible wavelengths being scattered equally (Prakash, 2002).

Detection of Electromagnetic Radiation

The radiation that is emitted reflected or scattered from a body generates a radiant flux density in its surrounding space which contains information about the bodies properties. To measure the properties of this radiation a collector and detector are used. The collector is a collecting aperature which intercepts the radiant field and focuses the energy into a detector. The collector for viisual, infrared and ultraviolet remote sensing is usually a lens or a reflecting surface. The detector then transforms the electromagnetic radiation into another form of energy such as heat, electric current or state charge (Elachi, 1987). These forms of energy are measured and converted into digital numbers that can be transformed into images that can be processed.

Plank's Law

Plank's Law determines the emission pattern spectra of electromagnetic radation of a blackbody as a function of it's wavelength and temperature.

Planks law shows that as the temperature of a body rises the peak of the emitted radiation shifts toward shorter wavelengths (figure 1)The peak of the sun's radiation is in the visible part of the electromagnetic spectrum and the earth's peak of radiation is in the thermal part of the electromagnetic spectrum.

Satellite and Airborne Sensors

There are many different satellite sensors that are used today. Different sensors have different spatial and spectral resolutions therefore the information they obtain have different uses.


Geologic Mapping

ASTER images are often used for geologic mapping.
Not only does this image show different strata in different
colors, but it also show the topography of the region

Forest Fires

One of MODIS's main uses is to help monitor forest fires.
This MODIS image shows forest fires in Idaho during the summer
of 2002.The red area on the image show are that were burining
during image aquisition while the gray area depict burn scares.

Volcano Monitoring

An ASTER imagae of a volcanic eruption over Mt. Etna Italy.
Not only can ASTER detect the thermal properites of lava flows it
also has the capability of detecting gas emmisions from the volcano.

Sea Ice & Glaciers

A Landsat 7 image of the largest glacier in Alaska.
Malaspina Glacier is located west of Yalcutat Bay and is
3,880 km squared. Movement of glaciers and sea ice is often
studied using remote sensing.

Urban Growth

A Landsat 7 image of Detroit, Michigan.
Remote Sensing is often used to study changes
to urban area along with the effects of that growth.

Vegetation Mapping

This SPOT image is mapping diifernt type of agricultural area.
Remote sensing is often used to detect changes in vegetaion
especially due to deforestation

References Cited

Lillesand and Kiefer, 1994, Remote Sensing and Image Intrpretaion, 3rd Edition, John Wiley and Sons Inc., New York.

Elachi, C. 1987 Introduction to the Physics and Techniques of Remote Sensing, Wiley – Interscience Publications, New York.

Sabins, F, 1997, Remote Sensing Principles and Interpretations, 3rd Edition, W. H. Freeman and Company, New York.

ASTER Web Page:

Landsat Web Page:

MODIS Web Page :

Prakush, Anupma, 2002 Web Page and Class notes:

Return to