Transcript Remote Sensing of Our Environment

Remote Sensing of Our
Environment
Using Satellite Digital Images to
Analyze the Earth’s Surface
CIR Film at Close Range
Air Photos
Artist’s Rendition of SPOT
Satellite
Definition of Remote Sensing
• Remote sensing is the science and
art of acquiring information
(spectral, spatial, temporal) about
material objects, area, or
phenomenon, without coming into
physical contact.
EMR
• In remote sensing, information
transfer is accomplished by use of
electromagnetic radiation (EMR).
Electromagnetic Radiation
Electromagnetic
Spectrum
Geraniums - Normal Color Film
Geraniums - CIR Film
Normal Color/CIR Comparison
Thermal Radiometer
Archeology Site - South Dakota
Big Brother Watching…..
Interactions between Matter and
Electro-magnetic Radiation
• All matter reflects, absorbs, penetrates and
emits electro-magnetic radiation in a unique
way.
• For example, the reason why a leaf looks
green is that the chlorophyll absorbs blue
and red spectra and reflects the green
spectrum
Types of Remote Sensing with
Respect to Wavelength Regions
• Remote sensing is classified into three types
with respect to the wavelength regions;
– (1)Visible and Reflective Infrared Remote
Sensing,
– (2)Thermal Infrared Remote Sensing and
– (3)Microwave Remote Sensing
Spectral Reflectance of Land Covers
Spectral reflectance of vegetation, soil
and water
Spectral Reflectance of Land Covers
Spectral reflectance of different
kinds of trees
Landsat MSS - Where??
Where?
Where?
Where?
Where?
Gemini Film Image
What Season?
See the Line?
Significant Variations in Land
Cover and Land Use
Ready to Go!
What Scale?
TM vs MSS
SPOT - Washington DC
Pacman Farm….
Gharb, Morocco
Gharb - Pre-Harvest
Gharb - Post-Harvest
Sakur, Japan
Chernobyl - 1986
Ocean Measurements
California Mosaic
Resolution
•
•
•
•
Spectral Resolution
Radiometric Resolution
Spatial Resolution
Temporal Resolution
Landsat MSS
• Spectral Resolution
–
–
–
–
Band 4 (0.5 – 0.6 um, green)
Band 5 (0.6 – 0.7 um, red)
Band 6 (0.7 – 0.8 um, photo IR)
Band 7 (0.8 – 1.1um, near IR)
• Radiometric Resolution
– 1 byte (256 levels (0 – 255))
• Spatial Resolution
– 80m (260ft)
• Temporal Resolution
– 16 days
Landsat MSS
• Orbital altitude – 570 miles
• 11.560 FOV – 115 mile swath
SPOT
• Spectral Resolution
– Band 1 (0.50 – 0.59 um, green)
– Band 2 (0.60 – 0.68um, red)
– Band 3 (0.79 – 0.89um, RIR)
• Radiometric Resolution
– 1 byte
• Spatial Resolution
– 20m
• Temporal Resolution
– 26 days vertically downward. Can move mirror 270, increasing
repeatability to 7x in 26 days.
SPOT
• Orbital altitude – 516 miles
• 73 mile swath
Commercialization of Space Remote
Sensing
Here is a SpaceImaging
high resolution
panchromatic scene that
shows the pyramids outside
of Cairo, Egypt
Quickbird-2 is the flagship of Digital Globe
The Pentagon (a year after it
was damaged by a terrorist
air assault) on the Virginia
side of the Potomac River
outside Washington, D.C.
2.8m spatial resolution.
Military Intelligence Satellites
The KH-12 series, the last for
which some specifications can
be found, is reputed to achieve
a resolution of 2+ cm, although
images of this sharpness haven't
been released.
Spatial Resolution
Detection vs.Recognition
San Francisco
2x Enlargement
4x Enlargement
8x Enlargement
NYC Landsat TM