Radome pulsed microwave questions

[Irishjunius]

I would like to know about radome emissions. Radome in question is located on the west coast of Ireland. Its purpose is monitoring of international aircraft passing overhead. It has been described as Type 2.

It emits at a power of 2.5 kW pulsed microwaves at a frequency of 1 GHz (according to one of its employees) or possibly at several frequencies according to how many aircraft are in the sky at the time (according to another employee).
Equipment keeps being updated but no info available to general public. Anybody got any thoughts on this?

What happens to microwaves that fail to come in contact with anything on their journey of 256 miles? Do they return to the radome or do they 'dissipate'?

Can there be a build up of 'dissipated' microwaves in the atmosphere?

Are the microwaves which detect something on their journey the only ones which return to their radome source?

We are told that no microwaves emit from the radome anything less than the horizontal and that there is a tilt of some 5 to 9 degrees upwards (which is pre-set in the factory). We want to know if the weather conditions, which can be unusual in this area (North Mayo) can affect the microwaves coming from the radome?

Do microwaves travel in a straight line only?

Are ICNIRP Guidelines globally recognised?

For electromagnetic fields up to 300 GHz, is 1997 the latest guidelines from ICNIRP guiding regulatory authorities? If so, why are authorities using information so out of date?

Would satellite navigation of international aircraft not be more appropriate in 2011 than having installations on the ground?

Are radomes located in communities where people live in close proximity to them dangerous to the health and safety of those indigenous people?

Local issues: Cancer clusters appearing in areas located close to the radome (10 - 12 years after it was first built), local people suffering from headaches and tinnitus, potatoes failing to thrive in areas where they have been grown for centuries and failing to keep after harvesting since this radome was erected.

Thank you for any help or advice.

 

[Drakkith]

Well, the following link explains what RADAR is, which is what you are describing. http://en.wikipedia.org/wiki/Radar

EM Radiation (Which includes everything from Radio waves on up to Gamma Radiation) is either absorbed by an object, such as the atmosphere or ground, is reflected off of an object, or continues unimpeded until one of those two things occur. Radar waves that do not hit a plane simply continue on forever unless the atmosphere absorbs them. They do not build up.

Are the microwaves which detect something on their journey the only ones which return to their radome source?

The microwaves that are reflected are the only ones detected by the radar. If the object absorb them all then the object is not detected by the Radar station.

Do microwaves travel in a straight line only?

Unless reflected or refracted by something yes.

For electromagnetic fields up to 300 GHz, is 1997 the latest guidelines from ICNIRP guiding regulatory authorities? If so, why are authorities using information so out of date?

If the information is still good info, then there is no reason to change it. That's all I can speculate on.

Would satellite navigation of international aircraft not be more appropriate in 2011 than having installations on the ground?

No. Satellites are extremely expensive and are hundreds to thousands of miles away from an aircraft. Other than using GPS I don't believe satellite navigation is useful. Also, I believe that radar used in the civilian world is more for tracking the aircraft from the ground to ensure proper flight paths than anything else.

Are radomes located in communities where people live in close proximity to them dangerous to the health and safety of those indigenous people?

Unlikely. The frequency of EM Radiation emitted is not ionizing and as long as you don't go beyond the fenced off areas near the Radome then you should not be affected.

Local issues: Cancer clusters appearing in areas located close to the radome (10 - 12 years after it was first built), local people suffering from headaches and tinnitus, potatoes failing to thrive in areas where they have been grown for centuries and failing to keep after harvesting since this radome was erected.

The number of different causes for these issues are enormous. One would have to investigate why and mark off a number of other reasons before assuming the radar was the cause.

 

[Irishjunius]

Thank you for your reply Dakkith. I had looked at Wikipedia sites before but they can be extremely intimidating for uninitiated perusers. However, I have tackled into them again and gradually I can manage to understand a little more and gain another answer or two.

What happens to microwaves that fail to come in contact with anything on their journey of 256 miles? Do they return to the radome or do they 'dissipate'?

I wonder what the significance of the 256 mile radius is? What happens at this distance to the microwaves - I was assuming they turned around and headed back to their source but obviously I was wrong. So, they keep going - adding to the so-called electro-smog phenomenon? Would this be more accurate?

The microwaves that are reflected are the only ones detected by the radar. If the object absorb them all then the object is not detected by the Radar station.

To what kind of objects do you refer? Wikipedia seems to call it 'clutter'. Presumably this includes humans, their homes, lands and all other living things. Are we talking about SAR then?

We want to know if weather conditions, prevailing in the location can affect the microwaves coming from the radome?

Can't find a definitive answer to this. If anyone out there knows, I'd be grateful.

For electromagnetic fields up to 300 GHz, is 1997 the latest guidelines from ICNIRP guiding regulatory authorities? If so, why are authorities using information so out of date?

Have now discovered a relevant short 2009 update - less than 2 pages. http://www.emfexplained.info/?ID=25608"

Are radomes located in communities where people live in close proximity to them dangerous to the health and safety of those indigenous people?

Plenty of other problems arise when they fence off land belonging to others unfortunately! But, we'll say no more!

 

[Drakkith]

I wonder what the significance of the 256 mile radius is? What happens at this distance to the microwaves - I was assuming they turned around and headed back to their source but obviously I was wrong. So, they keep going - adding to the so-called electro-smog phenomenon? Would this be more accurate?

Electro-smog? Never heard of it honestly. But yes, I believe they would.

To what kind of objects do you refer? Wikipedia seems to call it 'clutter'. Presumably this includes humans, their homes, lands and all other living things. Are we talking about SAR then?

Clutter is anything that the radar detects that it doesn't want to detect. Birds, atmosphere disturbances, ground, sea, manmade objects, etc. Radar is very unlikely to be detecting people, as most of the radar waves that do come close to the ground are absorbed very quickly.

Can't find a definitive answer to this. If anyone out there knows, I'd be grateful.

Radar can be affected by weather, yes. It really depends on the frequency used. Some frequencies can be easily blocked by weather effects while other may pass harmlessly through.

Plenty of other problems arise when they fence off land belonging to others unfortunately! But, we'll say no more!

What? I'm talking about fencing off the area around the radar building, not like multiple acres around the site.

 

[russ_watters]

Can there be a build up of 'dissipated' microwaves in the atmosphere?

No. They cease to exist when absorbed by something - including the atmosphere itself. Anything not dissipated by the atmosphere would simply escape into space.

Remember, microwave radiation is a part of the same type of phenomena as light. It obeys most of the same rules.