Remote Sensing of the Land Surface: High Spatial Resolution

1. Remote Sensing of the Land Surface:High Spatial Resolution Michael D. King & Compton J. Tucker Outline • Land remote sensing at high spatial resolution • Satellite sensors enabling remote sensing of land cover at high spatial resolution • Landsat RBV, MSS, TM, ETM+ • Spot HRV • Terra ASTER • Orbital characteristics • Instrument characteristics • Spacecraft, spatial resolution, swath width, sensor characteristics, and unique characteristics • Land properties as observed by Landsat and ASTER

2. Characteristics of Landsat Missions

3. Definition of Orbital Period of a Satellite The orbital period of a satellite around a planet is given by where T0 = orbital period (sec) Rp = planet radius (6380 km for Earth) H¢ = orbit altitude above planet’s surface (km) gs = acceleration due to gravity (0.00981 km s-2 for Earth)

4. Landsat-1, -2, and -3 Observatory Configuration Solar array Multispectral Scanner (MSS) Data collection antenna Return Beam Vidicon (RBV) cameras

5. Spectral Sensitivity of the Four Landsat MSS Bands • Bands compared with the spectral sensitivity of the three emulsion layers used in color and color infrared film

6. Landsat MSS Operating Configuration

7. Ground Resolution Cell Size versus MSS Pixel Size

8. Band 2 Band 5 Band 7 Band 4 Band 3 Band 1 Landsat 5 TM Landsat 7 ETM+ EO-1 ALI EO-1 Hyperion Bare soil Senescent vegetation Green Vegetation

9. Satellite systems and sensors

10. Sun-Synchronous Orbit of Landsat-4 and -5

11. Successful Launch

13. Landsat 7 Swathing Pattern

14. Swath Progression Pattern

15. Landsat-4 and -5 Observatory Configuration High gain antenna Multispectral Scanner (MSS) Solar array S-band antenna Thematic Mapper (TM)

16. Thematic Mapper Optical Path and Projection of Detector IFOVs on the Earth’s Surface

17. Schematic of TM Scan Line Correction Process (a) Uncompensated scan lines (b) Correction for satellite motion (c) Compensated scan lines

19. Side-Lap Composting, no interpolation

20. Side-Lap Composting, no interpolation

21. Multi-pass compositing, no Interpolation Before After

22. Landsat’s Bands • Landsat collects monochrome images in each band by measuring radiance & reflectance in each channel. When viewed individually, these images appear as shades of gray

23. Color Composites • The human eye is not sensitive to ultraviolet or infrared light • To build a composite image from remote sensing data that makes sense to our eyes, we must use colors from the visible portion of the EM spectrum—red, green, and blue

24. ‘True Color’ Landsat TM Image • This image was produced using the red, green, & blue bands from Landsat’s Thematic Mapper • Note the washed out appearance of the landscape due to atmospheric effects R = 0.66 µm G = 0.56 µm B = 0.48 µm

25. “False Color” Landsat Image Channels 4, 3, 2 Channels 5, 4, 2 • These images were produced using near-infrared, red, and green bands • Notice how vegetation is more clearly distinguished from nonvegetation

26. San Francisco Onion Skin Animation

27. Landsat 7 Launched April 15, 1999

28. Enhanced Thematic Mapper Plus (ETM+) • NASA & USGS, Landsat 7 • launched April 15, 1999 • 705 km polar orbit, descending (10:00 a.m.) • Sensor Characteristics • 7 spectral bands ranging from 0.48 to 11.5 µm • 1 panchromatic band (0.5-0.9 µm) • cross-track scan mirror with 185 km swath width • Spatial resolutions: • 15 m (panchromatic) • 30 m (spectral) • Calibration: • 5% reflectance accuracy • 1% thermal IR accuracy • onboard lamps, blackbody, and shutter • solar diffuser

29. Thematic Mapper Optical Path and Projection of Detector IFOVs on the Earth’s Surface

30. Landsat 7 Goals & Objectives • Land use and land cover change • Agricultural evaluations, forest management inventories, water resource estimates, coastal zone appraisals • Growth patterns of urban development, Spring run-off contaminants in lakes, land use in tropical rainforests, health of temperate conical forests, mapping wildfire hazards in Yosemite • Vegetation patterns • Annual cycle of vegetation dynamics, drought stress, and flooding • Dune reactivation in the US Great Plains, precision farming and land management • Glaciers and snow cover • Growth and retreat • Gradual changes in the Antarctic ice sheet • Geological surveys • Volcanic hazards and lava lakes

31. Chesapeake & Delaware Bays R = 0.66 µm G = 0.56 µm B = 0.48 µm May 28, 1999 Baltimore Washington

32. Benefits of Landsat 7 over other Missions • Mission Continuity • Spanning 25 years of multispectral imaging of the Earth’s surface, starting in 1972 • Global Survey Mission • Approximately one quarter of the Earth’s landmass is imaged every 16 days • Every landmass will have seasonal coverage • Affordable Data Products • Landsat 7 data products are available from the EROS Data Center • Prices dropped from approximately $5,000 (Landsat’s 4 & 5) to $600 (Landsat 7) per scene

33. Washington, DC Landsat 5 Infrared band Landsat 7 panchromatic band 1991 1999

34. Washington, DC Detail Landsat 5 Infrared band Landsat 7 panchromatic band 1991 1999

35. Phoenix Development and Growth:1973-1992 Multispectral Scanner (MSS)

36. San Francisco Bay from Landsat 7 R = 0.66 µm G = 0.56 µm B = 0.48 µm Bay Bridge Golden Gate Bridge Oakland Airport

37. Cape Canaveral R = 0.66 µm G = 0.56 µm B = 0.48 µm

38. Flood of the Mississippi River in 1993 Landsat 5 TM Before the floods After the floods

39. Flood of the Limpopo River in Mozambique • The Limpopo River in Mozambique before and after the flooding from Cyclone Eline • About 700 people were killed and thousands were displaced by this event Landsat 7 ETM+ August 22, 1999 March 2, 2000

40. Cape Town & the Western Cape

41. Landsat 7 Data Archived during First 400 Days of Operation

42. Bolivia from Landsat: 1984-1998 Thematic Mapper R = 2.21 µm G = 0.83 µm B = 0.56 µm Garden of the Gods Country Club Colorado College