Satellite Imagery and Remote Sensing. DeeDee Whitaker SW Guilford High EES & Chemistry

Transcription

1 Satellite Imagery and Remote Sensing DeeDee Whitaker SW Guilford High EES & Chemistry

2 Outline What is remote sensing? How does remote sensing work? What role does the electromagnetic spectrum play in satellite imagery? How can satellite imagery be applied in science classrooms?

3 Common Vocabulary Remote sensing- gathering data without direct contact. Satellite- in this case, a man-made machine orbiting the Earth that collects reflected radiation from the Earth s surface. Pixel-picture element or the size of the digital block of information Resolution- the clarity or amount of data stored in a pixel. Resolution relates to pixel size. The smaller the pixel the greater the resolution.

4 What is remote sensing? Identifying, observing, and measuring an object without coming into direct contact with it (NASA)

5 So many satellites and sensors According to NASAthere were about 3000 satellites operating in Earth orbit in 2012.

6 International Space Station is the largest, man-made Earth orbiting satellite. NASA Real Time Satellites in Google Earth by Analytic Graphics (2008)

7 US Satellite Orbits Constellation

8 How does Remote Sensing work? Satellite imagery is a special case of digital photography. Radiation bands in the electromagnetic spectrum that are reflected from the Earth s surface back into space can be collected by satellite sensors and stored digitally as pixels. The most common electromagnetic bands for satellite imagery are visible light, near infrared radiation (NIR), infrared radiation (IR), and ultraviolet radiation (UV).

9

10 What role does the Electromagnetic Spectrum play in RS?

11 R e fl e ct a n ce

12 Some satellites collect only the radiation that that is reflected from the surface of the earth. (Passive) Other satellites like JASON, emit radiation at 13.6 GHz and 5.3GHz and measure the time it takes for the round trip. (Active) Active satellites measure elevation and are used to generate topography.

13 EES Sensor Ranges Visible Spectrum- full color digital photography Infrared- heat Near-Infrared- vegetation Mid-Infrared- soils Ultraviolet- clouds and snow cover All color images require processing.

14 Differences Among Infrared Regions Near IR- (0.7-1)microns 740 K- ( K) Earth s surface and above Mid IR 5 to (25-40) microns Far IR ( ) K to 740 K only above the atmosphere (25-40) to ( ) microns ( ) K to ( ) K only above the atmosphere Reminder : C = K

15 Visible and Near IR Comparisons A B A B

16 Examples of Satellite Imagery NASA and Google Earth

17 How can scientists use IR data to study the earth s surface? Kohrs, Infrared Image

18 Landsat Program Land cover and land cover change Temporal: 16 days Spectral: 4-8 bands Spatial resolution: 30 m a.gov/features/landsat/

19 MODIS (Moderate Resolution Imaging Spectroradiometer) Temporal: Daily Spectral: 36 bands Global land cover and ocean RS Spatial: m Fire monitoring

20 IKONOS- commercial Temporal: On Demand Spectral: 4 bands, panchromatic Spatial: 1-4 m Local land cover

21 JASON (Active) Temporal: 10 days Spectral: NA (Active) Sea level Spatial: ~ 2 km _general.html

22 How can satellite imagery be applied to EES classrooms? Weather forecasting Storm tracking Ocean temperature monitoring Sea level changes Large scale land mass & land use changes

23

24

25

26 Summary Remote sensing allows us to observe and monitor the earth surface. Features on the Earth s surface can be interpreted using spectral/electromagnetic information. Satellites have a wide range of purposes.

27 Resources NC OneMap-data and imagery National Map-data and imagery Imagery Sources =3913&gclid=CP20qKO6xrACFYlk7Aodw0_QoA svg Google Earth NASA and NOAA