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Back in the early 1940’s Jonathan Dickinson State
Park was a top secret RADAR base. It was only active for a
few years but the work done here significantly assisted in winning
the war. Now that JD is this great state park we can still
see remnants of the base in some very out of the way location as
well as right along the road. I was chided last year
for making the names of my caches a little too generic and promised
this year to do a better job.
The cache is located along the paved bike trail in
the western portion of the park. The paved trail runs for a
mile along side the main road and then continues to the east and
finishes along the power lines. These trails while not paved
are in pretty good shape this year and are
rideable.
So get ready for RADAR 101.
This series of caches will give you a brief
overview of the different types of RADAR systems that are still in
use today.
Search radars scan a wide area with pulses
of short radio waves. They usually scan the area two to four times
a minute. The waves are usually less than a meter long. Ships and
planes are metal, and reflect radio waves. The radar measures the
distance to the reflector by measuring the time from emission of a
pulse to reception, and dividing by the speed of light. To be
accepted, the received pulse has to lie within a period of time
called the range gate. The radar determines the direction because
the short radio waves behave like a search light when emitted from
the reflector of the radar set's antenna.
Weather radars can resemble search radars.
This radar uses radio waves along with horizontal, dual (horizontal
and vertical), or circular polarization. The frequency selection of
weather radar is a performance compromise between precipitation
reflectivity and attenuation due to atmospheric water vapor. Some
weather radars uses Doppler shift to measure wind speeds and
dual-polarization for identification of types of
precipitations.
We've all looked at the output of a
weather radar before going out caching.
• Weather radar
• Wind profilers
• Millimetre cloud radar
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