1. Integration of sensors for photogrammetry and remote sensing 8 th semester, MS 2005

2. Course overview 1.Introduction to RS 2.Image geometry, georeferencing, orthorectification 3.Platforms for optical sensors 4.Microwave sensing 5.Digital airborne cameras, ALS

3. Introduction to remote sensing RS principle Electromagnetic energy –Sources of energy –Interaction with atmosphere and Earth surface Ideal and real RS system Optical sensors for RS –Photographic systems –Digital sensors Multispectral sensors Hyperspectral sensors

4. Remote sensing principle Information about an object, area, or phenomenon is obtained through the analyses of data acquired by a device that is not in contact with the object, area, or phenomenon under investigation (Lillesand) Specifically: Data collected by sensors detecting elmg. energy that are operated from airborne or spaceborne platforms Goal: inventory, mapping, and monitoring earth resources

5. Remote sensing principle Reference data (1) (2) (3) (4) (5) (6) (7) (8) (9) 1.sources of energy 2.propagation though the atmosphere 3.interaction with Earth surface 4.re-transmition through the atmosphere 5.sensing systems 6.sensing products 7.interpretation and analysis 8.information products 9.users

7. Energy interactions in the atmosphere Scattering –unpredictable diffusion of radiation by particles in the atmosphere –Rayleigh scatter – ‘blue sky’, haze in imagery Absorption –mainly due to water vapor, carbon dioxide, and ozone –atmospheric windows

9. Energy interactions with Earth surface features E I (λ)=E R (λ)+E A (λ)+E T (λ) E I (λ) – incident energy E R (λ) – reflected energy E A (λ) – absorbed energy E T (λ) – transmitted energy Reflectance specular diffuse (most interesting in RS)

10. Energy interactions with Earth surface features Spectral reflectance: р λ = E R (λ)/ E I (λ)

11. Detection of elmg. energy photographically –light-sensitive film (silver halide crystals) –range 0.3 – 0.9 µm (from UV to near IR) –high spatial resolution and geometric fidelity electronically –CDDs (charge coupled devices), A-to-D signal conversion –broad spectral range –electronic storage, transmittance, and processing of data Sensing systems active passive

12. Ideal RS system uniform energy source noninterfering atmosphere unique energy interactions at earth’s surface features sensor highly sensitive to all wavelengths with high spatial resolution real-time data processing advanced data users

13. RS projects Definition of the problem Evaluation of the potential of RS techniques for solving the problem Appropriate data acquisition (including reference data needed) Data processing and interpretation procedures Quality evaluation of results

14. Examples of RS applications Mapping (DEM, topographic mapping) Environmental engineering Geology Hydrology (soil moisture, glacier dynamics monitoring) Agriculture (crop type mapping, crop monitoring) Forest engineering (species identification) Disaster management (burn mapping, floods) Examples Advantege of multispectral, multiresolution, multitemporal data

15. Multispectral scanners Range of sensing 0.3 - 14µm (UV, visible, near-IR, mid-IR and thermal IR), several narrow bands Across-track scannerAlong-track scanner A.Oscillating mirror B.Detectors C.IFOV D.GSD E.Angular field of view F.Swath A.Linear array of detectors B.Focal plane of the image C.Lens D.GSD

16. Example: LANDSAT’s TM Band No. Wavelength Interval (µm) Spectral Response Resolution (m) 10.45 - 0.52Blue-Green30 20.52 - 0.60Green30 30.63 - 0.69Red30 40.76 - 0.90Near IR30 51.55 - 1.75Mid-IR30 610.40 - 12.50Thermal IR120 72.08 - 2.35Mid-IR30

17. Example: LANDSAT’s TM

18. Hyperspectral imaging Range of sensing from visible to mid-IR Hundreds of detectors measuring in narrow bands, typically 0.4 – 2.4 µm AVIRIS (Airborne Visible/Infrared Imaging Spectrometer)AVIRIS

19. Hyperspectral imaging

21. Spectral libraries http://speclib.jpl.nasa.gov/

22. Links Remote sensing tutorials: –NASA http://rst.gsfc.nasa.gov/Front/tofc.html –Ohio university http://dynamo.phy.ohiou.edu/tutorial/tutorial_files/frame.htm –Canada centre for RS http://www.ccrs.nrcan.gc.ca/ccrs/learn/tutorials/fundam/chapter1/chapter1 _1_e.html Remote sensing glossary http://www.casde.unl.edu/vn/glossary/intro.htm http://www.ldeo.columbia.edu/res/fac/rsvlab/glossary.html