Remote Sensing Kailua Bay, Oahu, Hawaii
Bellringer • Pick up an Electromagnetic Spectrum Worksheet from the front table. • You have five minutes from the time the bell rings to complete it. • After you have completed your Bellringer write your homework in your Planner
Ojectives • TLW be introduced to the main concepts of Remote Sensing • TLW be able to draw and label various images of Oahu. • TLW be able to locate Diamond Head from the remote sensing images of Oahu.
Demonstration • What color is the sky? • Why do you think the sky is this color? • Is there any time when the sky is a different color?"
Demonstration • Colors of the Sky • Make a prediction by describing what you think will happen when you shine a flashlight into the aquarium of water.
Demonstration • The shorter the wavelength of light, the more it is scattered by the atmosphere. Blue has a shorter wavelength, it is scattered ten times more than red light. • At sunset, light takes a longer path through the atmosphere. Most of the blue light has been scattered out.
Remote Sensing The science of obtaining and interpreting information from a distance, using sensors that are not in physical contact with the object being observed. Hyperlink of video in picture From atop Diamond Head. Image by H. Mamula
Remote Sensing Terms • Haze-A visual effect when the concentration of scattering agents is high. • NIR- Near infrared • Pseudoinvariant features- Manmade materials such as asphalt and concrete, or natural materials such as deep water bodies or dry bare soil areas.
Remote Sensing • What are the Three Categories of Remote Sensing Systems? • Reflected solar radiation sensors • Thermal infrared sensors • Imaging radar sensors
Examples of Remote Sensing • Your eyes detect electromagnetic energy in the form of visible light. • Your ears detect acoustic (sound) energy • Your nose contains sensitive chemical receptors that respond to minute amounts of airborne chemicals Eyes Ears Nose
Remote Sensing • The science of remote sensing in its broadest sense includes: • Aerial • Satellite • Spacecraft • Observations detect and measure electromagnetic energy, including visible light, that has interacted with surface materials and the atmosphere.
Remote Sensing Electromagnetic spectrum that is useful in remote sensing of the Earth’s surface. 0.4 0.5 0.6 0.7 UNITS 1 micrometer (μm) = 1 x 10-6 meters 1 millimeter (mm) = 1 x 10-3 meters 1 centimeter (cm) = 1 x 10-2 meters Blue Green Red ULTRAVIOLET Incoming from Sun VISIBLE INFRARED MICROWAVE (RADAR) Energy Emitted by Earth 0.1 μm 1 μm 10 μm 100 μm 1 mm 1 cm 10 cm 1 m Wavelength (logarithmic scale)
EM Energy Interaction Processes • Matter - EM Energy Interaction Processes The horizontal line represents a boundary between two materials. Transmission
EM Energy Interaction Processes • Emission & Absorption Emission The lower the temperature, the longer the wavelength of the emitted radiation. Absorption
EM Energy Interaction Processes • Specular Reflection The surface is smooth
EM Energy Interaction Processes • Scattering (Diffuse Reflection) Rougher surfaces cause scattering in all directions.
EM Energy Interaction Processes • The amount of energy absorbed varies in wavelength for each material in a characteristic way, creating a sort of spectral signature. Sensor EMR Source Scattering Absorption Scattering Scattering Scattering Emission Absorption Absorption EMR interactions in the atmosphere and at the Earth’s surface.
Categories of Remote Sensing Systems • Reflected solar radiation sensors Detect solar radiation that has been diffusely reflected (scattered) upward from surface features. Image by, USDA Forest Service Image shows reflected red light at 650 nm in red, reflected NIR at 850 nm in green, and thermal IR at 8 - 12 um in blue as viewed from above on 26 November 2007, between 13:58 and 14:19 PST.
Categories of Remote Sensing Systems • Thermal infrared sensors Sensors that can detect the thermal infrared radiation emitted by surface features can reveal information about the thermal properties of these materials. Image by, USDA Forest Service Image shows reflected red light at 650 nm in red, reflected NIR at 850 nm in green, and thermal IR at 8 - 12 um in blue as viewed from above on 26 November 2007, between 13:58 and 14:19 PST.
Categories of Remote Sensing Systems • Thermal infrared sensors Applications of thermal infrared images are possible, including mapping rock types, soils, and soil moisture variations, and monitoring vegetation condition, sea ice, and ocean current patterns. Image by, USDA Forest Service
Categories of Remote Sensing Systems • Imaging radar sensors These “active”systems “illuminate” the surface with broadcast microwave radiation, then measure the energy that is diffusely reflected back to the sensor. Radar sensors can always acquire an image, independent of cloud cover or whether it is day or night, they are very useful in monitoring change over time. Image by NASA.gov
Categories of Remote Sensing Systems • Imaging radar sensors Radar images are used to map landforms and geologic structure, soil types, vegetation and crops, and ice and oil slicks on the ocean surface. Hilly terrain dominates the right half and flatter surfaces the left half of this radar Image. Image by NASA.gov
Combing the 3 Categories of Image Data to Create Remote Sensing • We can learn even more by combining image data from different sensors. • Interpretation of the merged data set can employ rigorous quantitative analysis, or more qualitative visual analysis.
Images of Oahu Hyperlink hidden behind map.
Images of Oahu • Locate Diamond Head in the image • Use graph paper to draw the Thematic Mapper Simulator (TMS) image of Honolulu. • The image looks quite similar to how we would observe the city from an airplane.
Images of Oahu • Locate Diamond Head in the image • Use graph paper to draw the Shuttle Imaging Radar (SIR) image of Diamond Head. • Shows steep slopes and rough surfaces (at a wavelength of 24 cm) as very bright parts of the image, and smooth or non- reflective surfaces as dark.
Images of Oahu • In this set of three images, we inter-compare the oblique computer image with photographs taken from our aircraft flying along the coast.
Images of Oahu • Use the set of three images from the previous page & the map of Oahu to locate the following locations: • Pearl Harbor • Waikiki Beach • Queen Emma’s Summer Palace • Punch Bowl National Cemetery
Conclusion • What are the Three Categories of Remote Sensing Systems?
Conclusion • What are the Three Categories of Remote Sensing Systems? • Reflected solar radiation sensors
Conclusion • What are the Three Categories of Remote Sensing Systems? • Reflected solar radiation sensors • Thermal infrared sensors
Conclusion • What are the Three Categories of Remote Sensing Systems? • Reflected solar radiation sensors • Thermal infrared sensors • Imaging radar sensors
Resources • NASA.gov. Retrieved on February 17, 2010. http://southport.jpl.nasa.gov/cdrom/sirced03/cdrom/DOCUMENT/HTML/TEACHERS/MODULE02/MOD2SECB.HTM • Oahu Map. Retrieved on February 18, 2010. http://www.alohaupdate.com/Oahu/Images/oahu.jpg • Smith, R. Ph.D., 23 August 2006. Introduction to Remote Sensing Environment (RSE). MicroImages, Inc., 2001–2006 Microimages.com. Retrieved on February 17, 2010. http://www.microimages.com/getstart/pdf/introrse.pdf
Resources 5. USDA Forest Service. Retrieved on February 17, 2010. www.fireimaging.com/.../330/locmap%20copy.gif • Virtually Introduction to Remote Sensing Environment. Retrieved on February 17, 2010. http://satftp.soest.hawaii.edu/space/hawaii/vfts/oahu/rem_sens_ex/rsex.spectral.4.html • Wittlin, M. 8 October 2006. Beauty is in the Processing-Time of the Beholder. Brain & Behavior. Retrieved on February 17, 2010. http://seedmagazine.com/.../attractive_article.jpg