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Fundamentals of Satellite Remote Sensing – Chapter 5. Emilio Chuvieco and Alfredo Huete. Visual interpretation. + Low investment. + Builds upon photo-interpretation experience. + Includes a wide variety of criteria. - Analog: requires digitizing the output.
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Fundamentals of Satellite Remote Sensing – Chapter 5 Emilio Chuvieco and Alfredo Huete
Visual interpretation + Low investment. + Builds upon photo-interpretation experience. + Includes a wide variety of criteria. - Analog: requires digitizing the output. - Influenced by interpreter’s subjectivity.
Negative Film Positive Film Paper Facilitates paper reproduction. Multiple color combinations More quality Photo-products
Landsat image of the Portuguese coast in the original NASA format (Courtesy: R. Nuñez).
Hierarchic organization of visual interpretation criteria Spectral criteria COLOR BRIGHTNESS Simple spatial criteria Level of Complexity SHAPE SIZE TEXTURE Complex spatial criteria SHADOWS CONTEXT ASSOCIATION Temporal criteria PHENOLOGY: SEASONAL CONDITIONS (after European Commission, 1993).
Variation in brightness of different spectral bands of MODIS for our sample region (February, 19th, 2001) . Red band (B1); Near infrared band (B2) Short wave infrared (B7) Legend: (1) Snow, (2) Water), (3) Irrigated crops; (4) Bare Soils.
Processes in color formation YELLOW RED RED GREEN MAGENT YELLOW WHITE BLACK GREEN BLUE MAGENT CYAN BLUE CYAN Aditive Substractive
Blue Color composite Green Red
MODIS 214 MODIS 261 MODIS 275 MODIS 143
Different textures in a Landsat-7 ETM+ image of northern Tucson (Arizona). (September 3, 2000) (1) Smooth: grasslands; (2) Medium low: shrubs and grasslands; (3) Medium-high, forested areas; (4) Rough: build up areas (source: Global Land Cover Facility, GLCF)
Textures on high-resolution images (1) Smooth: grass; (2) Medium concrete roof; (3) Medium-high, clay roof ; (4) Rough: trees. Ikonos image of the University of Arizona, acquired on August, 2000 (source: http://visibleearth.nasa.gov/)
Spatial context This criterion makes it possible to discriminate irrigated crops (1) from golf fields (2). ETM+ image of Tucson.
Diagram for the computation of a the height of a building from its shadow length h ls
Shades Alcalá, KVR-1000 Washington, D.C., IRS
Patterns Examples of land cover identification based on spatial pattern recognition: a) factories; b) tropical deforestation, c) golf field, d) wave patterns
Shapes Shape recognition from satellite images: a) sport fields; b) factories; c) bullfight ring; d) harbor; e) combustible tanks; f) airplanes.
Large shapes Example of variable shapes in large areas: a) Appalachian relief in a MSS image; b) tropical cyclone in an AHRR image.
Stereoscopic view of the metric camera RMK 20/23 on Central Spain. The camera was installed on board the Space Shuttle in 1981 (Courtesy: R. Núñez).
Temporal dimensions in image interpretation DATE 1 DATE 2 INTERPRETATION MULTI-SEASONAL ANALYSIS DATE 3 DATE 1 INTERPRETATION MULTI-YEAR ANALYSIS DATE 2 INTERPRETATION
Seasonal variation Central Spain 5-5-98 21-7-97
Effect of geometric distortions on the image interpretation Tucson TM image acquired June 9, 1989 (source: http://aria.arizona.edu/) Tucson ETM+ image acquired September 3, 2000 (source: Global Land Cover Facility, GLCF).
Effect of the spatial resolution on the image visual interpretation Top: comparison between MODIS (left) and ETM (right) images of the Tucson area; Bottom: comparison between ETM+ (left) and Ikonos (right) of the University of Arizona’s campus
Comparison of three spatial resolution images over a sector of Alcala de Henares city (central Spain). Left: ETM+ (band 3, 30m), center: panchromatic channel (15 m), right: KVR-1000 (2m).
MODIS spectral bands of the study region (image acquired on February, 19th, 2001: From left to right and top to bottom: B3: 459-479 nm; B4: 545-565 nm; B1: 620-670 nm, B2: 841-876 nm; B6:1628-1652 nm and B7: 2105-2155 nm
MODIS band 1 (red) images of the study region acquired at different times of year. Left: February, 19th; Center: May, 21st; September, 25th. The bottom window shows the status of the Hoover dam in the same dates
Change detection analysis (city of Phoenix, Arizona) MSS 1974 TM 2002 (Source of images: http://aria.arizona.edu/)
Recent evolution of lake Chapala in central Mexico (Source: Atlas of our changing environment)