GE 113 REMOTE SENSING

Transcription

1 GE 113 REMOTE SENSING Topic 1. Concepts and Fundamentals of Remote Sensing Lecturer: Engr. Jojene R. Santillan Division of Geodetic Engineering College of Engineering and Information Technology Caraga State University

2 OUTLINE Part 1. Remote Sensing Definitions Broad/informal definitions Formal definitions Similarities and Differences of Remote Sensing with other fields Part 2. The Remote Sensing Process Key concepts and principles What are the processes? What are the elements involved? 2

3 EXPECTED OUTCOMES The students would be able to: Understand and define on their own what Remote Sensing is: informally and formally/technically Differentiate Remote Sensing from other fields. Identify the key concepts and principles of Remote Sensing Identify the processes and elements involved in Remote Sensing 3

4 PART 1. REMOTE SENSING DEFINITIONS

5 WHAT IS REMOTE SENSING? Key words: Remote from afar/at a distance Sensing being aware of / detecting / acquiring information Some Broad/General/Informal Definitions: knowing by looking/hearing/feeling from afar feeling without touching acquiring of data about an object without touching it acquiring information at a distance Pictures/graphics are not mine. They are of their owners. 5

6 Which one of these can be generally considered as remote sensing? Reading the texts in this slide. Having a telephone conversation Counting the stars at night Knowing your mother is angry by the look of his/her face Knowing that its raining outside. Knowing from a map that you need to travel several kilometers from your current location to reach your destination You found from a picture in your Facebook page that your friends are enjoying in a beach somewhere. You got annoyed because your classmates are noisy. ALL can be considered remote sensing. Information about something is acquired without being there physically. 6

7 Formal/Technical Definitions of RS (1) By the American Society of Photogrammetry and Remote Sensing (ASPRS): Remote Sensing is the measurement or acquisition of information of some property of an object or phenomenon, by a recording device that is not in physical or intimate contact with the object or phenomenon under study. Pictures/graphics are not mine. They are of their owners. 7

8 Formal/Technical Definitions of RS (2) By Lillesand, Kiefer & Chipman (2008)*: Remote Sensing is the science and art of obtaining information about an object, area or phenomenon through the analysis of data acquired by a device that is not in contact with the object, area, or phenomenon under investigation. Pictures/graphics are not mine. They are of their owners. *Lillesand, T. M., Kiefer, R. W., & Chipman, J. W. (2008). Remote Sensing and Image Interpretation 6th Edition. United States of America: John Wiley & Sons, Inc. 8

9 Remote Sensing as Reading Process Group Discussion/Recitation: Why is reading the texts in this slide considered a good example of Remote Sensing? englishclub.com

10 Remote Sensing as a Reading Process Eyes acting as a sensor It responds to light reflected from this slide. The data your eyes acquire are impulses/signals corresponding to the amount of light reflected from the dark and light areas displayed on the slide. These data are analyzed, or interpreted, in your mental computer to enable you to explain the dark areas on the slide as a collection of letters forming words. Beyond this, you recognize that the words form a sentence and you interpret the information that the sentences convey. And that information is: You are being asked why reading is a good example of Remote Sensing. 10

11 Group Discussion/Recitation How is Remote Sensing similar/different from surveying, cartography, and GIS? henrico.us clipartpanda.com Source: slideplayer.com/slide/ / 11

12 Similarities/Differences of RS from Surveying, Cartography and GIS Remote Sensing is much like surveying It can provide fundamental biophysical information including x,y location, z elevation, or depth Unlike much of surveying, Remote Sensing can obtain data over very large geographical areas rather than singlepoint observations. GIS and Cartography: they are not used to obtain fundamental information They can be used to show/display/process fundamental information They rely on data obtained by others (one of which is Remote Sensing) Pictures/graphics are not mine. They are of their owners. 12

13 Questions or clarifications? geo.tuwien.ac.at 13

14 Short Quiz (5 pts) Answer the following in 1/4 sheet of paper: In one sentence only, provide a technical definition or description of Remote Sensing. 14

15 Homework/Assignment (20 pts) In the formal definition of Lillesand, Kiefer and Chapman, Remote Sensing is considered as science and art. Research and explain why Remote Sensing is a science and/or an art. ANSWERS DIRECTLY TAKEN FROM INTERNET SOURCES WILL BE GIVEN A GRADE OF ZERO (0). Submit your answer in essay format next class meeting. In order to answer, you may use reference materials in the library or in the internet but please use your own words. No copying please. 15

16 PART 2. THE REMOTE SENSING PROCESS 16

17 Overview of the Remote Sensing Process (Audio/Video Presentation) Watch the video here: =3iaFzafWJQE 17

18 Remote Sensing as an Interaction of/with Light Energy The process can be summed up as the interaction between incident electromagnetic radiation (light energy) and the targets of interest, and how the results of the interaction are: captured by a remote sensor analyzed to extract useful information about the targets of interest for a specific application or purpose. 18

19 7 Elements of the Remote Sensing Process Canada Center for Remote Sensing 19

20 7 Elements of the Remote Sensing Process A. Energy Source or Illumination B. Radiation and its Interaction with the Atmosphere C. The Interaction of the Radiation with the Target of Interest D. Recording of the Reflected/Emitted Energy by the Sensor E. Transmission, Reception and Processing F. Interpretation and Analysis G. Application Canada Center for Remote Sensing 20

21 A. Energy Source or Illumination the first requirement for remote sensing is to have an energy source Illuminates or provides electromagnetic energy to the target of interest Common energy sources: The Sun The Sensor itself (releases its own energy) Canada Center for Remote Sensing Pictures/graphics are not mine. They are of their owners. 21

22 B. Radiation and its Interaction with the Atmosphere As the energy travels from its source to the target, it will come in contact with and interact with the atmosphere it passes through. This interaction may take place a second time as the energy travels from the target to the sensor Canada Center for Remote Sensing Not all energy emitted by the source goes into the Earth s surface 22

23 B. Radiation and its Interaction with the Atmosphere 23

24 C. The Interaction of the Radiation with the Target of Interest Once the energy makes its way to the target through the atmosphere, it interacts with the target Canada Center for Remote Sensing The interaction is dependent on the properties of both the target and the radiation. 24

25 D. Recording of the Reflected/Emitted Energy by the Sensor After the energy has been scattered by, or emitted from the target, we require a sensor (remote - not in contact with the target) to collect and record the reflected or emitted electromagnetic radiation. Canada Center for Remote Sensing 25

26 E. Transmission, Reception and Processing The energy recorded by the sensor has to be transmitted often in electronic form, to a receiving and processing station where the data are processed into an image. Canada Center for Remote Sensing 26

27 F. Interpretation and Analysis the processed image is interpreted, visually and/or digitally or electronically, to extract information about the target which was illuminated. Canada Center for Remote Sensing 27

28 F. Interpretation and Analysis (Example) Image Interpreted/Analyzed Image CSU Phil-LiDAR 2 28

29 G. Application The final element of the remote sensing process is achieved when we apply the information we have been able to extract from the imagery about the target in order to better understand it, reveal some new information, or assist in solving a particular problem. Some common applications Weather and climate monitoring Land-use/Land-cover mapping and change analysis Watershed management Disaster Management Natural Resource Mapping landcovertrends.usgs.gov Canada Center for Remote Sensing 29

30 Example Application of Remote Sensing to Map Vegetation Characteristic 30

31 Questions or clarifications? Source: 31

32 Summary Remote Sensing is the science and art of obtaining information about an object, area or phenomenon through the analysis of data acquired by a device that is not in contact with the object, area, or phenomenon under investigation. The Remote Sensing process can be summed up as the interaction between incident electromagnetic radiation (light energy) and the targets of interest, and how the results of the interaction are: captured by a remote sensor analyzed to extract useful information about the targets of interest; And on how the extracted information is used for a specific application or purpose. Canada Center for Remote Sensing

33 References/Further Reading Jensen, J.R. (2007). Remote Sensing of the Environment: An Earth Resource Perspective, 2nd Edition. New Jersey: Pearson Education/Prentice Hall. Campbell, J. B., & Wynne, R. H. (2011). Introduction to Remote Sensing 5th Edition. New York: The Guilford Press. Lillesand, T. M., Kiefer, R. W., & Chipman, J. W. (2008). Remote Sensing and Image Interpretation 6th Edition. United States of America: John Wiley & Sons, Inc. Mapping the Invisible: Introduction to Spectral Remote Sensing (You Tube Video). Available at Fundamentals of Remote Sensing (Online Tutorial). Available at 33