Transcript REMOTE SENSING and AIR PHOTO INTERPRETATION

REMOTE SENSING and
AERIAL PHOTOGRAPHY
Roger
Wheate
NREM100
Fall 2010
Remote Sensing
• information about an
object by a recording
device not in contact
with the object
• cameras, lasers,
scanners, radar
systems, Lidar
• the term did not exist
before satellites
(1960s) increased the
scope of aerial surveys
with digital scanning
Remote Sensing
• 1910s: First (wartime)
aerial photography
• 1940s: aerial photography
programs
• 1960s: first satellites:
Espionage, weather,
communications
• 1970s: Digital imagery for
earth mapping
• 2000s: free web images
Early aerial photography
(before planes):
balloons, pigeons and
mountain tops
Oblique photos from mountain peaks: Banff
Oblique photography
Post-1945: Panchromatic aerial photograph: Iqualuit
Aerial Photography
• Aerial photography = two sciences:
– Photogrammetry (=precise locations and heights)
– Air photo interpretation (=feature identification)
• Advantages over ground surveying
– Cost and time-convenience
– Historical record
Aerial Photography
• Flightlines
• Overlap
• Corrected and mosaiced
• Type: Pan, Colour, IR
Air Photo Interpretation
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Tone / colour
Texture
Shape
Pattern
Size
Shadows
Context
Colour photography – 2x as expensive
Infra-red photography – 3x as expensive
1:50,000
NTS maps
(from photos)
(1:20,000 BC
maps/data)
PG 93G015
Photos 1996
Printed 2000
Roads updated,
other 1982
Reprinted 2010
Roads updated
Others still 1982
BC aerial photography 2007
Digital aerial photography
www.terrasaurus.ca
Orthophotos as digital map layers: 1993, 2003, 2006
http://pgmap.princegeorge.ca/
BC ‘imap’: http://lrdw.ca
Applications
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All natural resources disciplines
– Navigation and mapping
– Forest inventory
– Geologic surveys
– Natural hazards
– Land use change
– Wildlife habitat assessment
Photos – 1:15,000 = 4km x 4 km;
1:40,000 = 10km x 10km
Satellite images: 60 x 60 km ; 185 x 185km;
500 x 500 km
Merge of satellite image and orthophoto
Remote sensing - Satellite imagery
Port Renfrew, Vancouver Island
Pre 1984 cutblocks in pink, 1984-91 in blue
• 1960s – weather satellites
• 1972 – Landsat 1
• 1982 – Landsat 4
• 1990s – more earthresources satellites
• 1999 – Landsat 7
(copyright removed)
• 2000 – high resolution
corporate satellites
• 2005 Web applications
Satellite orbits (800km altitude)
Landsat path: earthnow
Landsat image – Bowron Lakes 30 metre resolution
Vegetation Information and the
Electromagnetic Spectrum
• Visible
visible characteristics (RGB)
• Near IR
vegetation vigour / health
• Mid IR
vegetation and soil moisture
• Thermal IR
temperature / heat
• Microwave/Radar
texture e.g. high for forest
2003
2007
High resolution corporate satellites: Geoeye (50cm res.)
Cypress Bowl – Feb 19, 2010
Applications – remote sensing
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Geologic – faults, deposits, exploration
Vegetation – forestry, agriculture, ecology
Urban - land use, growth
Geography – regional and local studies
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ASTER:
http://asterweb.jpl.nasa.gov/
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Ikonos:
http://www.satimagingcorp.com/gallery-ikonos.html
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Quickbird:
http://www.satimagingcorp.com/gallery-quickbird.html
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Geoeye:
http://www.geoeye.com/CorpSite/gallery/Default.aspx
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BC mosaics:
http://www.lrdw.ca
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Google maps: http://maps.google.ca
http://www.lrdw.ca
NASA – images of the day
http://earthobservatory.nasa.gov/IOTD/
Google Earth (since 2005): aerial photography and satellite images
The giant dog you can see from space
Monday, June 9, 2008 BORIS the bull mastiff is so big that he can be seen lounging in his favourite
position in the garden - from space. The 89kg dog has been captured on Google Earth's satellite images.
His owners noticed an enormous brown blob on the image of their front garden and were stunned to
discover it was their pet. 'He was in his favourite place,' said Fran Milner, from Bournemouth.
We knew he was big but didn't think he was big enough to be seen from space.'
Google Earth: aerial photography and satellite images / mashups
Filmaps
http://www.thewildernessdowntown.com/