Clicking on the thumbnails below will allow you to see a larger
Here is a view of the "Sandbox" where we
will test the radar. Sand has similar reflective properties to snow.
The depth of the sand in this box is about two meters.
The silver piece is one of the metal targets that will
be placed in the sand. The metal target is made of half of a styrofoam
ball covered in aluminum foil. There is a small dowel through the
center to help with exact positioning of the target. There are also
air-filled targets of the same shape made of paper mache. The metal
targets should be more reflective and easier to see on the radar.
We will see if the radar detects all the targets.
These are the radar antenna that are attached to rails
on the sandbox. They can be positioned anywhere by using the computer.
The radar antenna move along tracks on two sides of
the "sandbox". Here is a close up of one of the tracks and
The placement of the targets is carefully planned. This
grid shows the placement of the targets in the sandbox.
The red arrows show the dowels of the targets sticking
up out of the sand. John will initially line up the radar antenna
with one of the targets.
John has planted the targets and is now raking the sand
around them to make it smooth.
Next he jumps on this sheet of metal to make the sand
more compact and level. This will make it more like the snow and ice.
John is squatting on the piece of metal to be sure the
surface stays flat while he smooths the surface by hand.
Now he is using the level to check the area he just
smoothed to make sure it is absolutely flat. Though the snow and ice
won't be level, during this test it is important to know the distance
from the top of the sand to the target.
When the targets are planted and the surface is raked
and smoothed, sand and dust go everywhere. It is very important that
all of the tracks are cleaned thoroughly before moving the antenna
along the track. First it has to be vacuumed.
Next the track has to be wiped down with a damp cloth.
Then it is wiped again to dry it. And you thought housework
The antenna in the starting position.
John carefully aligns the antenna.
Here he is checking the settings for the radar.
Here the radar antenna are moving. It takes about eight hours to
complete the test.
This is the radar image. You can see two targets at the bottom (red
arrows) that are 0.4 meters apart.
This is another radar image. The targets at the bottom of this image
are 0.2 meters apart. You can clearly see the difference as they are
This shows all ten targets. See if you can find them (it works better
if you use the larger image). If you aren't sure, use the grid that
we showed you before to help you find them.