1. Geography 372 Introduction to Remote Sensing University of Maryland Compton Tucker & Megan Weiner

2. Remote Sensing Creed I want to understand the world I must use the electromagnetic spectrum (few other options) I will not be limited by a sensory system (the human eye) optimized for viewing things in the light from a 6000 K star 93M miles away, whose electromagnetic irradiance also has to pass through Earth’s N 2 -O 2 planetary atmosphere

3. All alone in our neighborhood of space Apollo 12’s Classic Earth Rise from Moon

6. Remote Sensing Systems How do we discuss and catagorize remote sensing? “the resolutions” Spatial Spatial Resolution -- what size we can resolve Spectral Spectral Resolution -- what wavelengths do we use Radiometric Radiometric Resolution -- degree of detail observed Temporal Temporal Resolution -- how often do we observe

7. Beltsville Agricultural Research Center True & False Color Ikonos Satellite Data Beltsville Agricultural Research Center In visible light these trees look the same Near-infrared separates conifers (darker) from deciduous trees 400 500 600 700nm

8. Spatial resolution Each square in the image is one digital number for each spectral band. The dimensions of the square determines spatial resolution.

9. Better spatial resolution Mars “Face” Viking 1976 resolution = ~200 m Mars Orbiter 2000 resolution = ~10 m

10. Multistage Remote Sensing

11. Ground-based remote sensing

12. Air Photo: color film, airplane, 1-2 m detail Timothy Lake, OR

13. Landsat 30 m Columbia River Mt. St. Helens Mt. Adams

14. AVHRR 1 km Columbia River Olympic Pen. Yellowstone N.P. Mt. St. Helens

15. Satellite Remote Sensing of Earth SeaWiFS Land-Ocean Chlorophyll September 1997 to present …

16. Remote sensing uses the radiant energy that is reflected and emitted from Earth at various “wavelengths” of the electromagnetic spectrumRemote sensing uses the radiant energy that is reflected and emitted from Earth at various “wavelengths” of the electromagnetic spectrum Our eyes are only sensitive to the “visible light” portion of the EM spectrumOur eyes are only sensitive to the “visible light” portion of the EM spectrum Why do we use nonvisible wavelengths?Why do we use nonvisible wavelengths? The Electromagnetic Spectrum

17. our star Our Sun emits more light in the visible than any other part of the spectrum.

18. Amount of solar energy hitting Earth’s outer atmosphere is ~1370 watts/m 2

19. Rayleigh Scattering: why the sky is blue

20. Remote Sensing Systems: the Human Eye SpectralSpectral Resolution: 0.4-0.7 µ m SpatialSpatial Resolution: ~ 1-3 cm @ 20 m RadiometricRadiometric Resolution: ~16-32 shades B/W or ~100 colors

21. Invertebrate remote sensing Insects have remote sensing capabilities quite different from vertebrates and the octopus

22. Key Milestones in Remote Sensing of the Environment 1826 – Joseph Niepce takes first photograph 1858 – Gaspard Tournachon takes first aerial photograph from a balloon 1913 – First aerial photograph collected from an airplane 1935 – Radar invented 1942 – Kodak patents color infrared film 1950s – First airborne thermal scanner 1957 – First high resolution synthetic aperture radar 1962 – Corona satellite series (camera systems) initiated by the Intelligence community 1962 – First airborne multispectral scanner 1972 – ERTS-1 Launched – First Landsat satellite

23. Early photograph by J. Niepce circa1830

24. Nadir in his balloon

25. Nadir photograph of Paris

26. Balloon Photo of Boston 1836

27. Thaddeus Lowe’s Civil War Balloons U.S.Army of the Potomac 1861-1865 Massachusetts’ man, Professor and visionary, Lowe Observatory/Calif. Platform: Balloon Sensor: Telescope Data System: Telegraph

28. Thaddeus Lowe, circa 1861-1865 remote sensing for military purposes. Then, as now, newest developments are always in the military sphere

29. Remote sensing early in the airplane era

30. U-2 Spy Plane 1954-1960 Flew at 70,000’ over USSR air defenses

31. SR-71 Blackbird super-sonic spy plane

32. CIA’s Corona Program CIA’s Corona Program 1960-1972 >100 missions Followed after U-2s… Platform: Spacecraft Sensor: Camera Data System: Film Drop Started: August 1960 Coverage: 7.6 Bil mi 2 Spatial Resolution: early missions @ 13 m, later missions @ 2 m Spectral Resolution: visible and visible-near infrared (both film) Radiometric Resolution: equivalent 2 4 to 2 6 (4 to 6 bits)

33. CIA’s Corona Program CIA’s Corona Program Washington Monument 1967

34. Ikonos 1 m panchromatic imagery 2000

35. MODIS Land Reflectance and Sea Surface Temperature