Thierry wrote:

Hi,

I received this message from a colleague but I cannot answer him. I d
not know these systems.
Could you help me ?

My company has installed a Radar Tower for Port survaillence. The tower
is about 50 meter height on top of the of a 3 stories building roof and
my office building just below the tower on the same level, 20 meter away
from the tower. At the same time, the surrounding is my working area (
Jetty Terminal for ships loading and unloading activities ). I can say
that I'll be around that area 12 hours a day for another 20 years.

My question:

Is it safe to work in that area????

Thanks in advance
Thierry
http://www.astrosurf.org/lombry




So, what about Radar then...

First, There are two "kind" of RF radiation, non-ionizing and ionizing and
effects emanating from very high voltage nearby different materials.

Normally, non-ionising is to be more or less compared to sun light.
An overdose of non-ionising radiation gives the same effects than sun stroke
gives you, you heat up your body and the same symptoms occur if overheated.

As long as you are not overheating, there should be no harmful effects on
you. The problem are always to determine a narrow angle beam, radiating
towards sensitive parts of the body, like brain and eyes. The long term
effects of a heated brain are probably still debated. However, it's
probably not good for you. A narrow angle beam does not give the same full
body heating that "switches" your body reaction as it's only a part of you
that gets overheated, not the whole body!
If you are stupid enough to look into a wavegiude with full power on, be my
guest!

Now then to the nasty part, the ionising radiation. This radiation creates
residual effects even after the emitted radiation is switched off.
Typically radiation like Gamma radiation etc. This kind of radiation could
also create secondare types of radiation from materials in the environment.

Treat the ionising radiation like plague or cholera, avoid avoid avoid.


Now, radar radiation is only non-ionising RF radiation, let be with high
intermittent power and sometimes with stupidly high power.
Looking into an active waveguide will probably burn off your eye nerve or
something very bad for you.

If you are standing near a RF radiating radar station, the average energy is
what heats you up and the peaks are so short that even if they are Mega
Watts, the average energy transfer to your body is low.

Going up in frequency more or less moves the RF towards light, still with
the same effects.

OK, so it's not that bad is it? No? Wrong! Some frequencies are really bad
for us because different parts of our bodies absorbs different amount of
energy on different frequencies.

Let's take a party example... Many key fobs, alarm buttons for car locks
etc, operates on 418MHz. It happens to be approximately where a normal head
are resonating... Try walking just about out of range for your alarm/lock
button for your car, point the key fob against your head and press the
unlock key, voila, in most cases, you increase the range of the key fob.

So what? Just be aware and take a look in the health and safet chapter of
the ARRL handbook. It's all there and also how much more dangerous it is
with different frequencies.

The safest place are almost always under an antenna so don't fret over the
mobile phone mast on the roof of the school! I would be more concerned if
it was on a neighbouring house...


Cheers


Dan / M0DFI