1. Remote Sensing Data Acquisition

2. 1. Major Remote Sensing Systems

3. Major Remote Sensing Systems ► Aerial photography ► Electro-Optical remote sensing ► Microwave remote sensing ► Close range remote sensing

4. Aerial Photography ► Detector ► Process ► Vehicle ► Products: aerial photographs

6. ► http://nationalmap.gov/viewer.html http://nationalmap.gov/viewer.html ► http://www.abc.net.au/news/events/japan-quake- 2011/beforeafter.htm http://www.abc.net.au/news/events/japan-quake- 2011/beforeafter.htm http://www.abc.net.au/news/events/japan-quake- 2011/beforeafter.htm

7. Electro-Optical Remote Sensing ► Detector ► Process ► Vehicle ► Products: Digital images

8. http://earthobservatory.nasa.gov/Newsroom/Ne wImages/images.php3?img_id=4396 Buffalo, NY November 20, 2000

9. http://www.esri.com/news/pressroom/hurricanemaps.html Biloxi Coast–Before Hurricane Katrina, April 12, 2005 Biloxi Coast–After Hurricane Katrina, August 31, 2005.

10. Microwave Remote Sensing ► Uses antennas as detectors ► Passive microwave systems ► Active microwave systems, RADAR

11. http://www.erh.noaa.gov/buf/ http://rst.gsfc.nasa.gov/Sect8/Sect8_3.html

12. Close Range Remote Sensing

13. ► Visual interpretation vs. digital image processing

14. 2. Resolutions ► Spectral resolution ► Radiometric resolution ► Spatial resolution ► Temporal resolution

15. Spectral Resolutions AVIRIS Landsat 7 French SPOT DS-1260 1.0  m 2.0  m AVIRIS Landsat 7 French SPOT DS-1260 1.0  m2.0  m AVIRIS Landsat 7 French SPOT DS-1260 1.0  m2.0  m

16. Spectral Resolutions GreenRedNear InfraredNIR http://rst.gsfc.nasa.gov/Intro/Part2_17.html ► The dimension and the number of specific wavelength intervals in the EM spectrum to which a sensor is sensitive, e.g. B, G, R NIR bands

17. Radiometric Resolution ► The sensitivity of a detector to differences in signal strength as it records the radiant flux reflected or emitted from the terrain 256 levels 16 levels 4 levels 2 levels 8 bit 4 bit 2 bit 1 bit

18. Spatial Resolution ► A measure of the smallest angular or linear separation between two objects that can be resolved by the sensor, 30m, 1m, 1km 10m 20m40m80m

19. Temporal Resolution ► How often a given sensor obtains imagery of a particular area, e.g., 16 days, daily

20. Pixels and IFOV ► Pixel - picture element ► IFOV - Instantaneous Field of View the ground area viewed by the sensor at a given instant

21. 3. Color Theory ► Additive primaries ► Subtractive primaries

22. Additive Primaries ► blue, green, and red superimposing blue, green, and red light: blue + green + red = white green + red = yellow green + blue = cyan red + blue = magenta

23. Color Theory ► Yellow, magenta, and cyan are complements of blue, green, and red, respectively ► Various combinations of the three primaries produce different colors

24. Subtractive Primaries ► yellow, magenta, and cyan each absorbs its complementary color from white light yellow = white - blue magenta = white - green cyan = white - red

25. Subtractive Primaries ► Superimposing yellow, magenta, and cyan dye: yellow + magenta + cyan = black yellow + magenta = red yellow + cyan = green magenta + cyan = blue

26. True and False Color Images

27. http://www.crisp.nus.edu.sg/~research/tutorial/opt_int.htm

28. ► Readings Chpt 2.7

29. 4. Introduction of Satellite Systems ► Land observation satellite systems vehicles - spacecraft devices - electro-optical sensors images - digital images target - earth resources vehicles - spacecraft devices - electro-optical sensors images - digital images target - earth resources

30. Satellite Systems ► Advantages vs. aerial photography provide a synoptic view systematic, repetitive coverage multiple spectral information digital format for quantitative analysis less expensive

31. History of Satellite Systems ► Landsat (Land Satellite) system - launched in 1972 - first satellite for observation of the earth's land areas - important in earth resources studies and a areas - important in earth resources studies and a model for later satellite systems model for later satellite systems

32. History of Satellite Systems ► Early Landsat (1,2,3) was named Earth Resources Technology Satellite (ERTS) and designated by a letter, i.e. A,B,C, renamed later as Landsat 1, 2, 3 ► Early Landsat applied spectrums used in aerial photography but at a satellite altitude ► Early Landsat carried Return Beam Vidicon (RBV) and Multispectral Scanner (MSS) sensor systems ► New generation of Landsat (4,5,7) carries MSS and Thematic Mapper (TM) and other more sophisticated sensor systems

33. Satellite Orbits ► Geosynchronous orbits ► Sun-synchronous orbits ► Inclination ► Ascending and descending nodes ► Ascending and descending nodes

34. Geosynchronous Orbits ► Revolve at an angular rate that matches the earth's rotation ► Weather satellites, communication satellites ► Views the full range of variation of solar illumination http://www.crisp.nus.edu.sg/~research/tutorial/spacebrn.htm

35. Sun-Synchroneous Orbits http://www.crisp.nus.edu.sg/~research/tutorial/spacebrn.htm ► Maintain a constant angular relationship with the solar beam, the satellite will always pass overhead at the same local time for similar illumination and shadowing conditions http://www.youtube.com/watch?v=LttI1IofXRI

36. Satellite Orbits ► Inclination the angle between the orbital plane and the equatorial plane ► Coverage of the earth's surface http://www.atmos.umd.edu/~owen/CHPI/IMAGES/orbitss.html

37. Satellite Orbits ► Descending node - the point the satellite crosses equator on southward track ► Ascending node - the point the satellite crosses equator on northward track http://www.ccrs.nrcan.gc.ca/ccrs/learn/tuto rials/fundam/chapter2/chapter2_2_e.html

38. Satellite Orbits ► Most satellites cross over the equator at about 9:30am, an optimal time with respect to sun angle and cloud cover

39. Readings ► Chapter 6