Images I See - Knowledge I Possess

Objectives:

• Students will explore perception, via use of acetate transparent grids for scale, proportion and measurement of distances.
  
• Students will use observation skills to identify characteristics of an object at pre-determined intervals (5-meter spans up to 25-meter distances.)
  
• Students will identify remote sensing images of trees from different altitudes, to compare the scales at which they are visible as an object, vs. a reflection of temperature or color.
  

Time Duration:
Two 45-minute sessions. (If students make measuring strings in one session)

Grade Level: 4-8

Concepts Explored:
scientific processes, energy, scale and structure, communication, comparison, measurement, classification, sequencing, organization, recording, interference and synthesis

Vocabulary:
scale, structure, proportion, perspective, point of reference, span, reflection, distance, silhouette, detail, coordinates

Grouping: Groups of 3

Materials Per Group:

• measured string with 5 meter interval knots/marker of tape (25 meters long)
  
• 3 copies of checkered grid on plastic overhead projector sheets
  
• 2 erasable/overhead pens
  
• 1 thermometer
  
• writing pad or clipboard with paper
  

Advanced Preparation:
Cut measured lengths of yarn for students to tie knots or place tape markers at 5 meter intervals, up to the length of your playground. In order to make this preparation, a class period in math could be utilized and integrated with this remote sensing lesson.

You will need enough yarn or string to have one length for every 6 students.

Have enough overhead or erasable pens to have one for every three students in your class.

Teacher Resources:
USGS maps with coordinates, maps with grids

Supplies:
You may use several of the images on remote sensing already in the other lessons for application in this lesson.

Yarn/string may be donated by a local sewing shop or garden supply store.

Technology:
Images from the OTTER CD-ROM, volumes 1-5. NASA , "Oregon Transect Ecosystem Research Project - Satellite, Aircraft and Ground Measurements".
CD-ROM "Small Blue Planet", What Now Software, 2303 Sacramento, San Francisco, CA 94115

Teaching Tips:
If it is possible, you can place enough markers on the playground, using a rotating measuring wheel ahead of time.

Procedures:

1. In groups of three, partners trade off drawing the outer perimeter of each other's body as seen from a distance on a clear acetate sheet marked with a grid with lines one centimeter apart; the acetate sheet is placed on a clipboard. The idea is to draw the outline of the distant student on the grid when he/she is 25 meters away, then decreasing the distance by intervals of 5 meters and repeating the drawing on the grid.
   

2. The third student in the group takes notes on the descriptions of detail, clarity and brightness that each partner sees in each other, and as described by each other. Starting from 25 meters, each student traces and describes their partner. As they decrease the distance at intervals of 5 meters, and delineate the silhouette of each other, they will be applying the concepts of depth perception, distance, and reflection. Several trials may be necessary to train the eye and to capture the most effective characteristics to be observed from each other; i.e. lighting, shadows, relative size compared to an object on the background or next to the partner far away, and measurement of temperatures at each interval. [Note: One student might be on a grassy area, while his/her partner may be on the blacktop of the playground. This will give a very dramatic exchange of information and data.]
   

   Students can then make a team study of an object, such as a tree, using all of the techniques learned up to this point which include temperature measurements, reflective patterns as seen through diffraction lenses and spectroscopes, shadow analysis, distance, angle of light, intensity and colored filter comparisons.
   

   Each team will complete a study made on the selected tree over a period of time, recording times and as much data as possible from the ground.
   

   Illustrations and diagrams of what it would look from the air and how it looks from the ground are to be included.
   

   A grid map of the area surrounding the object with the measurements of the object and perimeter is also a component of the report prepared by each group. Students can use string and popsicles sticks to delineate on the ground a scale grid on their object. If yarn and sticks are not available, use hardware store string for chalk marking. Sprinkle the chalk dust into the container, pull string out over the area selected. Snap the string onto the surface to leave the line of chalk on it. Measure the next location for the line and do the same process, until your grid is complete.
   

3. Given remote sensing images of trees from different altitudes, compare your images to those on the remotely sensed images provided. From which altitude would a single tree be seen? Which of your images do you think resembles the area you selected? Why?
   

   Using images from OTTER, and other mapping remote sensing images of Earth, examine several images of landscapes to identify the altitude at which trees are identifiable as individual trees/objects vs. a color image of the temperatures of the tree against its surrounding area.
   

Assessment:
How does the exercise on the grids apply to the remote sensing technology?

What is the use of having proportional grids and how can they be applied in other fields?

Explain.

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