1. Class 10: Earth-orbiting satellites
Thursday 4 February
Class 10: Earth-orbiting satellites
and Review
No Reading
Last lecture: Spectroscopy, mineral spectra

2. Orbit Platform Sensor C-130 Sputnik Sputnik 2 with Laika 1957 Sputnik
1999
EOS

3. Airborne platforms – test beds, flexible paths
SEBASS Hyperspectral TIR sensor in a Twin Otter

4. Orbits
Key elements:
- eccentricity
- inclination
- periapsis

5. Inclination
Low inclination
High inclination

6. Hubble Space Telescope –
low inclination
most Shuttles -

7. Exception: SRTM
i=58º

8. High-inclination orbits

10. Special case –
Sun-synchronous orbit
(i ~ -81º)
Satellite is overhead at same local solar time all year
Why would you choose
- late morning?
- mid afternoon?
- early morning?

11. Global coverage

12. Sensor characteristics
spatial resolution and field of view
spectral resolution
spectral coverage
number of bands
Spatial resolution depends on experiment
high – spatial detail, less emphasis on spectroscopy
moderate – environmental monitoring
low – weather, oceanography
Spectral resolution
panchromatic
multispectral
hyperspectral (imaging spectroscopy)

13. Spectral coverage
Optical
reflected sunlight
thermal infrared
LiDAR
Microwave
passive
Radar
Gamma ray, X ray, geophysical (magnetic, gravity fields)

14. Thematic
Mapper
LANDSAT – SUN-SYNCHRONOUS ORBIT

15. ESS 421 - 1st half topics covered in class, reading, and labs
Images and maps - (x,y,z,l,t)
Temporal data - Time-lapse movies
Spatial data - Photos and interpretation
Spectral data
Electromagnetic spectrum
Absorption and Beer’s law (t=e-kz)
Transmission
Reflection
Scattering and Lambert’s law  R=Io(cos i)/p
Interaction of light and materials
Electronic processes (VNIR)
- electron transition (VIS), sharing (UV), crystral field (NIR)
Vibrations and overtones (SWIR-TIR)
Gas, liquid, glass, crystalline
Spectra of common materials
leaves, soil, water, clouds, snow, iron oxides, hydrated minerals

16. ESS 421 - 1st half key areas for midterm (Tuesday, 12 February 9:30-10:20)
Questions may be drawn from labs, lectures, text
Basic remote sensing parameters
irradiance, radiance, and their units
the electromagnetic spectrum
thermal emission
Atmospheric effects and scattering processes
Scattering and reflection from surfaces
Spectroscopy fundamentals
Spectra of common materials