Radar waves safe for humans?

[meirriba]

Our radars send out pulses that have defined width and height and defined angle of radiating these pulses. When the unit is in a normal mounted height on the mast all of the radiation goes above your head.
When on cabin top you will be in the line of fire so to speak, loosing effectively info from the area your body obstruct. Range of radar will be much lower and clutter higher.
My advice - discard the idea.

[dietervoegeli]

From Raymarine Radar Installation Manual

Radio Frequency Radiation Hazard
The radar antenna emits electromagnetic energy at microwave
radio frequencies which can be harmful, particularly to
your eyes. DO NOT look at the antenna at close range.
It is important that the radar is turned off whenever personnel
are required to come close to the scanner assembly. It is
recommended that the radar scanner is mounted out of range
of personnel (above head height).
The maximum power density level which is considered safe for
general public exposure is 10 W/m2, and for occupational exposure
it is 100 W/m2. The distances from the radar scanner
within which these levels may be exceeded are given below:
Model Distance to 100 W/m2
point
Distance to 10 W/m2
point
RD418D
Max power density at any
distance is <100 W/m2 1.0m (worst case)
RD424D
Max power density at any
distance is <100 W/m2
1.0m (worst case)

[hellosailor]

" Are there health issues by being on the same level as the radar?"

Radar is microwave radiation. Exactly the same as your microwave oven.

So, if you think it is safe to sit IN your microwave oven...by all means then, sit within a foot or two of your radar dish.

Ah, really...someone should have explained all this to you before installing a radar. And I'm betting it is all covered in the OWNER'S MANUAL for that radar.

Even if your radar is mounted on the usual stern pole, crew standing up on the foredeck can still be within the beamspread of the radar. You really need to find and run the numbers. On the bright side, standing by the radar will also help dry out your clothes on rainy days. :-)

[thomm225]

Originally Posted by Tkeeth

Wouldn't it be better to use real info than just ask a bunch of people you don't know?

WHO | Electromagnetic fields and public health: radars and human health

Marine radars can be found on small pleasure boats to large ocean going vessels. Peak powers of these systems can reach up to 30 kW, with average powers ranging from 1 to 25 W. Under normal operating conditions, with the antenna rotating, the average power density of the higher power systems within a metre of the antenna is usually less than 10 W/m2. In accessible areas on most watercraft, these levels would fall to a few percent of present public RF exposure standards.

Yeah, the marine radar on sailboats are very weak as compared to say air traffic control radar or surveillance radar.

The ones I'm most familiar with had a peak power of 1 megawatt and I have been in from of those many times with no ill effects so far

We were told as techs just make sure you don't get between the feedhorn and the antenna with the transmitter on

The new ATC Radars have less power these days because they are more efficient, but back in the day the transmitter would have maybe an 8500 volt power supply and that got boosted

We had these old UPS-1 radars that still had tubes and the thyratron tube was almost a foot tall by maybe 3 inches wide

Radar type UPS-1

(sketch from JSP 6 via Richard Vernon)

The UPS-1 is a lightweight assault radar which can be lifted and positioned by Wessex type helicopters. It has a limited early warning performance but no height finding capability. It is fitted with Moving Target Indication (MTI). It has a limited fighter control capability. (from JSP 6)

Frequency : 1250 - 1350 Mhz
Wave length : L-band
Aerial rotation : 15 r.p.m.
Air transportable : Yes
Aerial : Parabolic slatted reflector
Vertical beam width : 10o
Horizontal beam width : 3.5o
Peak power : 1000 kW
PRF : 267 (800 on MTI)
Pulse length : 4.2 uS (1.4 uS on MTI)
RX amplifier : Lin, bandwidth 145
Range accuracy : ±2 nm on 275 nm range scale
Range resolution : 0.5 nm at 20 nm
Bearing accuracy : 1o
Bearing resolution : 4o at 50 nm
Height accuracy : N/A
Range on "Canberra" at 20,000 feet : 150 nm
Range on "Canberra" at 40,000 feet : 150 nm

Editors note: I am indebted to Richard Vernon for providing the sketches and the technical details of British operated versions of the UPS-1 tactical radar.

https://www.google.com/search?q=mari...IFj7Nrj-7qjNM:

[alaskaflyfish]

In the aviation world the smaller radar units utilized in general aviation aircraft had warning stickers plastered under the domes stating "do not stand in front of the radar while activated". The associated picture was of the typical stick figure man being pelted with radiation waves. Whatever that is worth. This was in the late 1990's.

[transmitterdan]

Originally Posted by thomm225

The ones I'm most familiar with had a peak power of 1 megawatt and I have been in from of those many times with no ill effects so far

We were told as techs just make sure you don't get between the feedhorn and the antenna with the transmitter on

This is very bad advice. I am aware of people dying whilst sitting in front of high power microwave antennas. They were not between the feed horn and the reflector.

For many reasons the answer to the OP's question is "find a better place to put the radar consistent with the installation manual's specifications".

[thomm225]

Originally Posted by transmitterdan

This is very bad advice. I am aware of people dying whilst sitting in front of high power microwave antennas. They were not between the feed horn and the reflector.

For many reasons the answer to the OP's question is "find a better place to put the radar consistent with the installation manual's specifications".

The only way you might be able to die sitting in front of a radar like that was if you had a pacemaker or something (and I doubt it even then), but since this was a military radar installation and the old guys were around 30 years old, no one died

It's just the way it was done back in the day.

The radar we used for air traffic control was also the one used by other detachments for surveillance since it's range was 275nm

Our radar was mounted on a van which only stood about 9'-10' off the ground and was transmitting it's peak power pulse at 1 megawatt

The control tower was about 40' tall and maybe 50' in front of the radar.

https://www.google.com/search?q=mari...SaU7-w17gky9M:

We also had PAR radars mounted on tripods that had to be leveled daily (for the proper glide slope) out by the runway for final approach

https://www.google.com/search?biw=12...OriaeDYBeN6uM:

By the late 70's we had the ASR's . First was the ASR-8 then it went from there. It's the type you usually see at major airports today
https://www.google.com/search?q=asr-...eLz-3-vss4SeM:

[DeborahLee]

Before they were called micro-wave ovens they were called radar ranges. If you want kids don't soft boil the eggs.

[witzgall]

There is some very bad advice given here. Any radar with a magnatron (and yes, there are even "New" radars with them) poses a heath risk if you get in the path of the radiation.

There are some new radars that are solid state, that do not pose a radiation risk. So the answer is that you need to research the specific make and model you are considering.


Chris

[Cadence]

Originally Posted by DeborahLee

Before they were called micro-wave ovens they were called radar ranges. If you want kids don't soft boil the eggs.

Nor the nuts.

[roland stockham]

Originally Posted by Cadence

They say the new radars are safe. If yours is old you night as well crawl in your microwave oven.

It depends totally on output 4kw is still 4kw would stick to the principal of aligning the beam clear of crew stations with any radar

[Cadence]

Originally Posted by roland stockham

It depends totally on output 4kw is still 4kw would stick to the principal of aligning the beam clear of crew stations with any radar

I wouldn't want to be in front of any of them, even that the new ones are not suppose to be a problem. 2kw, 4kw or 20, If you want to have children?

[NevisDog]

Originally Posted by mrybas

Hi,
My radar used to be mounted on a tall pole well above deck, but I would like to mount it on top of the cabin. I sometimes sit on the cabin top while underway to keep watch. Are there health issues by being on the same level as the radar?

Years ago, crewman on fishing vessel was painting the roof of the wheelhouse while radar scanner was left on. Eventually he fell over as if drunk and was rushed to hospital. No idea of long-term effects but those microwaves are definitely unsafe - avoid at all costs.

[thomm225]

Originally Posted by witzgall

There is some very bad advice given here. Any radar with a magnatron (and yes, there are even "New" radars with them) poses a heath risk if you get in the path of the radiation.

Two of the radars I mentioned above have magnetrons. The new ASR series had a klystron in the transmitter.

Another radar we maintained was the FPN Series PAR Radar and sometimes we'd be standing directly in front of the transmitting reflector and some jackass would turn on the transmitter and yell....."you are now sterile!"

We were late teens early 20's in those days

I'm simply giving you "real world" experience.

Another ATC PAR would be this one.

Here's an early version and if I remember correctly this one had a magnetron but used SCR's instead of a thyratron to discharge the PFN for the final pulse output

https://www.google.com/search?q=fpn+...=1503697114256


Here is a video of part of a Klystron they use in the transmitter of the ASR Series Radars. These are the radars with the red reflectors you see at airports today

The klystron is red and the metal part below is the oil tank for cooling. It's one of the new low voltage systems since it only uses 3,000 volts

https://www.youtube.com/watch?v=YPRNaSo2kms

Here's the reflector you see at the various airports for the radar in the video above. It's a bit stronger than your sailboat radar system:

https://www.youtube.com/watch?v=Z0mpzIBWVG4

[Rorzech]

I have a 3G with a range of 23 NM and the picture on the box is of a 7 year old youngster hugging the dome demonstrating how safe it is and that it uses less power than a cell phone that is pressed against you temple for long periods of time. They insist its safe to mount it anywhere you too.