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