Welcome Geomatics in the Classroom!

1. Welcome Geomatics in the Classroom! Power Point Presentation adapted by Claude Brun del Re Canadian Space Agency Agence spatiale canadienne Ressources naturelles Canada Natural Resources Canada

2. What is Geomatics ? Geomatics for Educators

3. Geomatics • Term originally created in Canada • Geomatics is the science and technology of gathering, analyzing, interpreting, distributing and using geographic information. Geomatics encompasses a broad range of disciplines that can be brought together to create a detailed but understandable picture of the physical world and our place in it. These disciplines include: • Mapping and Surveying • Geographic Information Systems (GIS) • Global Positioning System (GPS) • Remote Sensing

4. Canada’s Role in Geomatics • Canada exports ~ $300 million worth of geomatics products and services. • Growth rate of 15 to 20 per cent per year. • Demand for GIS products and services is expected to exceed $10 billion per year. • Geomatics is one of the fastest-growing technology sectors and Canada is a recognized leader, both in its development and in the provision of Geomatics software, hardware and value-added services. • Natural Resources Canada- • Geomatics Canada • Canada Centre for Remote Sensing • Centre for Topographic Information • Aeronautical Charts & Technical Services • Legal Surveys & International Boundary Commission • Geodetic Survey

5. Remote Sensing

6. Satellite weather maps Ultrasounds Speed radar Sonar (for ships, bats or dolphin) Photos CAT scans x-rays List examples of remote sensing technology in your every day life

7. Definition and Process Target Sensor Platforms Electromagnetic Energy Interpretation RADARSAT REMOTE SENSING

8. Remote Sensing - A Definition Indirect (remote) observations (sensing) Remote sensing is the science (and to some extent, art) of acquiring image data and deriving information about the Earth’s surface without actually being in contact with it. Remote sensing will give information about an object called a target

9. Who could give me two common sensors? Our eyes A camera

10. Satellite Space shuttle Aircraft Balloon Ground base tower How does remote sensing work?Far away from the target, on what we call a platform.Here are some types of platform

11. Remote Sensing Process • Energy Source or Illumination (A) • Radiation and the Atmosphere (B) • Interaction with the Target or Surface (C) • Recording of Energy by the Sensor (D) • Transmission, Reception, and Processing (E) • Interpretation and Analysis (F) • Application (G)

12. Passive Sensor • Passive sensors detect or “sense” reflected solar radiation What does a passive sensor need to sense the earth?

13. Active Sensors • Active sensors produce and receive their own electromagnetic energy They produce their own illumination and they operate in the microwave region

14. Some Atmospheric Interactions • Energy will interact with the atmosphere on its way in and out • Ozone, nitrogen, CO2 and water vapour affect incoming energy • Energy affected if wavelength is < or = the particle size • Atmospheric windows are wavelengths not affected by the atmosphere

15. Absorption • Some substances absorb certain wavelengths of energy • UV rays absorbed by ozone • LW IR and SW microwaves absorbed by water vapour • These wavelengths are not suitable for remote sensing Scattering • Occurs when molecules are larger or equal to wavelength • Rayleigh scattering - selective scattering (UV, Blue sky) • Non-selective - scatters all visible wavelengths (clouds)

16. Atmospheric Windows

17. Terrain Interactions • Radiation that reaches the Earth’s surface can be: Absorbed (A); Transmitted (T); and Reflected (R). • This will vary with the type of object. The type of interaction will depend on the wavelength of the energy and the material and condition of the feature. • Look at different objects, for example an egg, a green apple and a tomato.

18. Diffuse and Specular Reflectors Diffuse Specular rough surface smooth surface

19. Electromagnetic Energy

20. Ultra-Violet Microwave Gamma Ray Infrared Visible Radio X-ray 0.003nm 0.03nm 0.3nm 3nm 30nm 0.3  m 3  m 30  m 300  m 0.3cm 3cm 30cm 3m 30m Electromagnetic Energy • Electromagnetic energy is used to illuminate the target in remote sensing • Electromagnetic spectrum: Shorter wavelength Longer wavelength

21. Visible Spectrum Visible Wavelegths • Violet: 0.4 - 0.446 mm • Blue: 0.446 - 0.500 mm • Green: 0.500 - 0.578 mm • Yellow: 0.578 - 0.592 mm • Orange: 0.592 - 0.620 mm • Red: 0.620 - 0.7 mm

22. The basic colours of light

23. IR and Microwaves • Reflected IR: 0.72 mm to 3.0 mm • Thermal IR:3.0 mm to 15 mm • Microwaves:1 mm to 1 m

24. VIR or Optical Remote Sensing

25. Visible / Infrared (VIR) • Colours we perceive are combinations of electromagnetic energy • VIR (visible infrared) or optical sensors capture energy reflected by targets in the optical and IR wavelengths • Each target reflects or emits these types of energy in different amounts

26. Spectral Response • Different objects reflect, absorb and transmit energy in differing amounts • An object also transmits, reflects, and absorbs each wavelength differently • Spectral responses enable us to identify different objects on images • An object’s spectral response may change over time

27. Spectral Response - Leaves • Chlorophyll absorbs red and blue • Reflects green • Greenest in summer • Internal leaf structure reflects near IR

28. Bands or Channels • Each sensor has a purpose (vegetation, ocean, ice, weather) • Certain wavelengths provide more information about certain targets • To perform their tasks, sensors on satellites detect energy in very specific, narrow bands or channels of electromagnetic energy

31. VIR/Optical Sensors

32. Spatial Resolution Fine Resolution Coarse Resolution

33. Swath • Total field of view • Width of the image in ground distance • For satellites, variesbetween 10s to 100sof kilometres

34. Orbits • Geostationary Near-polar sun-synchronous

35. GOES • Geostationary Operational Environmental Satellite • Operated by NOAA to for weather forecasting and monitoring • 5 spectral bands (green-red to infrared) • Geostationary above the equator at 75 degs E and W • Resolution 1 to 4 kilometres

36. NOAA-AVHRR • Advanced Very High Resolution Radiometer • Used for meteorology and other applications (vegetation) • Sun-synchronous, near-polar orbits(830-870 km above the Earth) • Ensure that data for any region of the Earth is no more than six hours old • visible, near, mid infrared,& thermal IR • 3000 km swath, 1 to 4 km resoloution

37. Landsat • Landsat-1 was launched by NASA in 1972 • Landsat 7 was launched in 1999 • ETM (Enhanced Thematic Mapper) 8 bands VIR and Thermal IR • 30 metre resolution • 185 kilometre swath width • Lots of archived data • Near-polar, sun-synchronous orbits - 705 km

38. SPOT • Système Pour l’Observation de la Terre • French commercial satellites • SPOT 1 -1986 • SPOT -2 operational, SPOT-4 just launched • Sun-synchronous, near-polar orbits at altitudes around 830 km • 2 Sensors MLA and PLA • PLA - black and white • MLA - 3 visible bands (blue-green-red) • 60 to 80 km swath • 10 to 20 m resolution

39. RADARSAT-1 • Canada’s first earth observation satellite • Launched November 4, 1995 • Monitoring the Arctic (ice) is its main role • Unique, flexible, “steerable” sensor • Many swath width choices • Many incidence angles available

40. RADARSAT-1 Orbit Geometry - Circular, Near polar - Sun-synchronous Inclination - 98.6° (from the equator) -Passes to the right of the North Pole Period - 100.7 Minutes Repeat Cycle - 24 days - 14 orbits per day Coverage - Global: 4,5 days - North America: 3 days - Arctic: daily Altitude - 798 km

41. New Small Sats • 1 to 5 metre resolution • All commercially built • IKONOS • Earlybird • QuickBird

42. RADAR

43. RADAR • RADAR is an acronym for RAdio Detection And Ranging • A microwave (radio) signal is transmitted towards the target • The sensor detects the reflected (or backscattered) portion of the signal

44. RADAR Images • Radar images “look” like black and white photographs • Tones of gray correspond to the amount of radar energythat is returned to the sensor • The stronger the backscatter or the more energy that is returned to the sensor, thelighter that area or object will appear on the final image

45. RADAR Reflection • There are three general types of reflection:speculardiffusecorner calm

46. Advantages • Own energy source (images anytime of day) • “Sees” through clouds (images anywhere) • Provides good view of topography • Sensitive to surface roughness • Provides information on moisture content

47. Disadvantages • Side-looking geometry creates distortions • Radar speckle • Excessive loss of data in mountainous areas due to shadows

48. Radar Sensors • SEASAT - NASA 1978 • lasted only a few months • ERS-1 - ESA 1991-95 • 30 metre resolution • ERS-2 - ESA 1994 • 30 metre resolution • JERS-1 - Japan 1992 • 18 metre resolution

49. Satellite Imagery

50. What is an Image? • Image is a visual view of the energy reflected by the target • Satellite images are digital: they are made up of numbers usually from 0 to 255 where 0 is black and 255 is white • The numbers (radiance value) are arranged in rows and columns • Each square is called a PIXEL • A number or a value of reflected energy is stored for each pixel