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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.
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Remote Sensing of Our Environment Using Satellite Digital Images to Analyze the Earth’s Surface
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).
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
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.
IKONOS • 1999 launch • Spatial Resolution: • B/W: 82-cm • Multispectral: 4-meter
IKONOS • Spectral Range • 526–929 nm445–516 nm (blue)506–595 nm (green)632–698 nm (red)757–853 nm (near IR) • Revisit Time • Approximately 3 days