GOG 385

LAB 8

RADAR IMAGERY

(revised 06/01)

The purpose of this lab is to familiarize you with RADAR imagery. RADAR is different than the other imagery we have worked with this semester because it is an active sensor. Thus, the return characteristics are somewhat different. In completing this lab one will need to use a grid over the image. The grid should be placed over the image so that the upper left hand corner is even with the start of the image, NOT the entire transparency. The letters will correspond to the vertical columns while the numbers will correspond to the horizontal columns. That is, the letters go across the top (North) and the numbers go down along the left side of the image. If the grid is placed correctly there will be some stripes in Box D/7.

This image is an airborne synthetic aperture image flown for the USGS. It is an X-band (ca. 3cm) HH polarized and rectified image. The image was flown in a north-south direction.

The maps needed for this lab are the following NYS DOT sheet maps at a scale of l/24000:

Niskayuna

Troy North

Mechanicville

Saratoga Springs

Quaker Springs

Round Lake

1. What is the definition of Look Direction? What is the look

direction of this image?

2. What is a radar shadow?

3. Locate by grid coordinates

a. Round Lake

b. Junction 9 and I-87

c. Cedar Bluff

d. Saratoga Springs

e. Stillwater Trailer Park

f. Crescent Dam

4. Identify the terrain feature or location at:

a. O/34

b. H/7, I/7

c. I/13

d. G/18

e. N/22, O/22

f. M/24-25

5. Why are the bodies of water so dark?

6. What are the dots in the Hudson River? What are the lines

across the Hudson River? Why can you see them?

7. What are the 3 'bumps' at N/9, 0/10-11? How can you tell?

8. Why does Mechanicville look so bright? There are other bright

areas on the image. If they are not cities then what are

they, and what probably causes this?

9. How can you delineate the mountain ridges on this image and

why?

10. What causes the bright lines at D/7?

11. How can you delineate the Saratoga Racetrack?

12. Complete an overlay of the image. Include roadways, cities and

water bodies. Include the appropriate key. Compare your overlay with the

map as to features and details that are detectable. Describe

or list your conclusions and observations. How can RADAR be used to upgrade maps in

general?

13. What is the approximate scale of the radar image?