The portion of the electromagnetic spectrum at the peak of the Sun’s radiation is called the visible band because the human visual perception system is sensitive to those wavelengths. Thus, as the graph shows, the Sun emits more energy than the Earth, and the Sun’s radiation peaks at shorter wavelengths. Hotter objects also radiate energy at shorter wavelengths than cooler objects.
Hotter objects radiate more electromagnetic energy than cooler objects. The vertical axis of the graph represents the magnitude of radiation emitted at each wavelength. The axis has been interrupted three times at the long wave end of the scale to make the diagram compact enough to fit on your screen. Note that the horizontal axis is logarithmically scaled, so that each increment represents a ten-fold increase in wavelength. Values along the horizontal axis of the graph range from very short wavelengths (ten millionths of a meter) to long wavelengths (meters). The graph above shows the relative amounts of electromagnetic energy emitted by the Sun and the Earth across the range of wavelengths called the electromagnetic spectrum. X-rays, ultraviolet rays, visible light, infrared light, heat, microwaves, and radio and television waves are all examples of electromagnetic energy.Ī portion of the electromagnetic spectrum, ranging from wavelengths of 0.1 micrometer (a micrometer is one millionth of a meter) to one meter, within which most remote sensing systems operate. Electromagnetic radiation is a form of energy emitted by all matter above absolute zero temperature (0 Kelvin or -273° Celsius). Most remote sensing instruments measure the same thing: electromagnetic radiation. Add comments and questions of your own, if any.Ĭomments and questions may be posted on any page of the text, or in a Chapter-specific discussion forum in ANGEL. Read comments and questionsposted by fellow students. See the Calendar tab in ANGEL for due dates. Instructions are provided for each activity.ĪNGEL > Lessons tab > Chapter 8 folder > Chapter 8 Graded Quiz.
View the global distribution of Landsat scenes at USGS’ Spacetracks site.Study remote sensing fundamentals and case studies at USGS’ Earthshots site.Go to ANGEL > Lessons tab > Chapter 8 folder > Practice quizzes are not graded and may be submitted more than once. You can also navigate the text via the links in the GEOG 482 menu on the left. Click on the links at the bottom of the page to continue or to return to the previous page, or to go to the top of the chapter. Chapter 8 Checklist (for registered students only) Step You may find it useful to print this page out first so that you can follow along with the directions. The following checklist is for Penn State students who are registered for classes in which this text, and associated quizzes and projects in the ANGEL course management system, have been assigned. Classifying Landsat Data for the National Land Cover Dataset We try to keep links up to date on a semi-regularīasis, but have no control over these sites, and links might get broken.\( \newcommand\) Is a selection that might be of interest. Seeing new ones appear, while older ones are updated, moved, or disappear. There is a wealth of remote sensing education resources on the Web.
0 kommentar(er)
