Presentation on theme: "Remote Sensing 2009 How to Analyze Remote Sensing Images Rocky Mountain Coach’s Clinic Colorado Springs, CO January 9-10, 2009."— Presentation transcript:
Remote Sensing 2009 How to Analyze Remote Sensing Images Rocky Mountain Coach’s Clinic Colorado Springs, CO January 9-10, 2009
Presented By: Mark A. Van Hecke National Science Olympiad Earth/Space Science Event Rules Committee Chair Anchor Bay High School Fair Haven, MI http//:www.mvanhecke.net
Objectives: Identify the basic elements of visual object recognition used to study remote sensing images
Objectives: Describe change detection methods used in the analysis of remote sensing images including Image Differencing and Image Ratioing Analyze selected remote sensing images to recognize the causes and consequences of global warming
Visual Object Recognition The most basic elements of analyzing a remote sensing image-that is the deriving of information from it include: Shape Size Texture Tone or Color Pattern Shadow Site Association
Shape Many Images include characteristic shapes that can be used to identify features In this oblique image of the City of Detroit, you can see Comerica Park- home of the Detroit Tigers against a backdrop of the central business district.
Shape Natural features are not created by human activity and appear irregular. Man-made features appear as straight lines or smoothly curved lines on images. ACTIVITY On this 1982 LANDSAT Image of Detroit, Michigan Identify features A, B and C. On the worksheet table, tell whether each is a natural or man- made feature. Also, identify what each of the features is
Size The size of objects on remote sensing images can be determined by the scale of the Image or by a comparison with other objects on the Image of a known size.
Size Some remote sensing images such as this USGS Image of Chernobyl shown here include a scale that allows you to easily measure distances from one point to another.
Size In most remote sensing images, you will need to determine scale by using the approximate measurement of a known feature. ACTIVITY In this Google Earth Image of Richmond, Michigan taken in 2005, measure the distance in YARDS from Point A to Point B
Texture Texture refers to the ‘roughness’ or coarseness of features on the Image.
Texture Man-made features such as roads, highways and parking lots have a smooth texture, while natural features often have a rough, choppy texture. ACTIVITY On the Richmond, Michigan Google Earth Map identify Points C, D and E. On the worksheet table, identify whether they are natural or man-made features, tell what each is and describe their texture as smooth or rough.
Tone or Color In panchromatic (black and white) images, the lighter and darker shades of features are referred to as Tone.
Tone or Color The tone of features on the Image is dependent upon the roughness or texture of the features. ACTIVITY On this black and white photograph of Harrisburg, Pennsylvania Identify features A, B and C. On the worksheet table, tell whether each is a natural or man-made feature. Also, identify what each of the features is and describe their roughness and texture. Is the tone of each feature on the Image dark or light?
Tone or Color In color images, the color seen in the Image may be a natural color, or a false color image depending on the spectral band used. Both are images of Detroit, Michigan. The one on the left is natural and the one on the right false color.
Pattern The perspective of remote sensing images allows us to discern patterns that would not be otherwise apparent. This false color Image of the Detroit area shows evidence of the original French ‘long-lot’ surveying used over 300 years ago. Long-lots allowed everyone access to the Detroit River and other area waterways.
Pattern Remote Sensing Images can be used to discern land use patterns. ACTIVITY On your Google Earth Image of Richmond, Michigan, identify the land use patterns of Points F, G and H as Agricultural, Commercial, or Residential. Write your answers on the Worksheet table and be sure to include a reason why you made this choice.
Pattern ACTIVITY: Identify which of these rivers is a mature river and which is dystrophic River A River B
Shadow Shadows help to identify features on remote sensing images by showing the familiar side of an object. Shadows can also be used to find the relative height of objects on the Image.
Site or Association Objects not easily recognized by themselves can often be identified by their relative position to known surrounding objects. ACTIVITY On the Google Earth Image of Richmond, Michigan, identify the likely purpose of the building located at Point I
Site or Association Remote sensing Images also allow us to discern associations between natural features as well. ACTIVITY Why would most of the trees be coniferous in this Image of Michigan’s Upper Peninsula along the Lake Superior shoreline? You should be able to give at least two reasons.
Change Detection Remote sensing images allow us to detect changes in regions and ecosystems over time. The 1989 and 2003 images of the Aral Sea between Kazakhstan and Uzbekistan in Central Asia show significant changes in the amount of water area.
Visual Change Detection Two methods used by geographers to determine change over time shown in two images of the same geographic location include Image Differencing and Image Ratioing.
Image Differencing Image differencing is an image analysis technique used to determine changes between two images over time. The ‘difference’ in two images is calculated by finding the difference between identical pixels in each image.
Image Differencing ACTIVITY Lay your Transparency Grid over the top of the Aral Sea Images similar to the one shown to the left. Now count the number of squares in the grid occupied by the Aral Sea that are water and also count the number that are land. Report the results in the Worksheet table.
Image Ratioing Image Ratioing highlights spectral variations in the appearance of identical images over time by ratioing data from different spectral bands.
Image Ratioing ACTIVITY Lay your Transparency Grid over the top of the Aral Sea Images similar to the one shown to the left. Go ahead, you can use your figures from the last Activity for your base count. Now determine the ratio of change. Report the results in the Worksheet table.
Global Warming Remote sensing images can be used to study a number of phenomenon related to global warming. These include: Deforestation Melting of Glaciers Flooding Changing Weather Patterns Changes in Phytoplankton
Deforestation ACTIVITY: Use your Transparency Grid to determine the amount of forested land and the amount of deforested land in each Image as well as the ratio of change Image AImage B
Sources of Images You can find many sources of public-domain remote sensing images that you can use to prepare for the Remote Sensing competition from these and other sources: NASA Earth From Space Website. One of my favorites for remote sensing images NASA Advanced Spaceborne Thermal Emission and Reflection Radiometer website. Lots of specific topic remote sensing images. Google Earth. If you don’t have it, you don’t know what you are missing. Free software for your computer, or you can purchase advanced versions.
Conclusion Remember the three event parameters: Use of remote sensing images to identify natural and human activities that affect the environment Use of remote sensing images to identify and analyze the effect of natural and human activities that affect the environment Analysis of charts, tables and graphs