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Weather Monitoring Frequencies Subject to Pollution
jd writes "In a case of technology vs. technology, the ICU (the body governing the use of radio frequencies around the globe) has been asked to secure radio frequences used for weather monitoring. In-car radar, mobile phones and other commercial and military applications are now using these same frequencies. However, weather satellites can't simply be re-tuned. There is only one very narrow band that detects water vapor but not liquid water, for example. This frequency has been sold to developers of car radar systems. The more this happens, the less useful weather radar and weather satellites will be. The noise will simply swamp the data, making what is collected useless. The article doesn't give a 'doomsday' timeframe, when we'll have no better ability to forecast the weather than they did in the 1800s, but that is what they are talking about."
Well, I am not sure how great we are at predicting the weather now.
A kid at my son's school collected and analyzied common RSS weather feeds for a science project.
He collected the data and used it to judge how accurate the weatherman's predictions were.
Within 5 degrees and 25% chance of rain, he gave them credit. They got credit 50ish percent of the time.
He then analyzied other ways of predicting the weather.
By just saying that the weather today will be the same as the weather yesterday, he got credit 50ish percent of the time.
I don't say this to belittle the weather people. I do this to say that the techniques we use now are not the greatest in the world. If we need those frequencies because they are the only ones that work, then maybe the gov't should buy them back. However, if those frequencies are used because that's the old school way of doing it, well, they aren't working at that great now.
Don't bother asking the FCC for help - they're too worried about someone saying fuck or showing their tits. Seriously tho, what sort of idiot would actually sell these frequencies if they knew what they were used for?
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Why would your car radar be useful if the signal it emits is attenuated by water vapour? Drive through some fog & you're in trouble.. ?
No Norm, those are your safety glasses; I'll wear my own thanks...
"BSD: Free as in speech. Linux: Free as in beer. Windows 10: Free as in herpes." --Man On Pink Corner in #52607549.
Question to those who might know this - assuming the ITU agrees to these restrictions, how would they enforce them? The radar frequency was presumably sold by a national agency (a la FCC) which is clearly making money off the sale and doesn't seem to care about the reasons. So how would the ITU go about forcing them to behave?
Our cars are more important than anything else. Everyone should know that by now, including weathermen who can't predict the weather anyway.
Take the cheese to sickbay, the doctor should see it as soon as possible - B'Elanna Torres, "Learning Curve"
Oh, wait, I think that was the 1980s. In the 1880s, we had that thing with a man with a brolly and a woman in a summer dress hanging from seaweed. You could tell the weather according to which one came out of the house. AFAICT, the reliability was much the same as today.
My uncle Jack sticking a wet finger in the air and saying "Arrh, it looks like a [fine|rough] day tomorrow - I think I need a wee dram!" was more fun though!
Sent from my ASR33 using ASCII
The FCC has the power to ban the sales and use of any device that would cause interference to these frequency bands. I've owned radio transceivers that were made obsolete and worthless by FCC decisions to reallocate spectrum to other uses. The FCC had no obligation to compensate me for the loss in value of the radio equipment or to offer me other spectrum to replace what was lost. If car radar units are a problem, the FCC can prohibit their sales and use.
Mea navis aericumbens anguillis abundat
Radar detectors, and most radio receivers, do transmit low-powered signals on the same or similar frequencies to those that they receive. It's called local oscillator leakage/radiation. It's especially common in consumer grade electronics equipment. If you look at the block diagram of a superheterodyne receiver, you will find one or more local oscillators that are used to mix down the incoming signals to fixed intermediate frequencies for filtering, amplification and demodulation. These local oscillators are often a source of radiation due to poor design and shielding. Radar detector detectors and TV detector vans take advantage of this by listening for local oscillator radiation.
Mea navis aericumbens anguillis abundat
Like this would never happen.
"It is a greater offense to steal men's labor, than their clothes"
The radar in question is for follow collision avoidance. You set cruise control, and this stuff makes sure that you are not cruise controlling yourself into the rear end of the car ahead of you.
-Rusty
You never know...
Ever been to LA...
You can drive in any direction for between 5 and 20 hours depending on day and traffic conditions, and never leave the monotonous suburban landscape. It's the results of unplanned, unconsidered, growth. From space it looks like the great god of suburban blight dropped it "Splat" from high altitude like some surreal cow patty.
What the hell (you might ask) has any of that got to do with this article. The answer is that the same kind of thinking (or kack there of), is behind the morass that is our use of the electromagnetic spectrum.
Empire building, despotism, political back-biting, greed and intrigue, technology working around the ideocy that is our regulatory system, and nobody asking whether the left hand knows what the right hand is doing... A Chinese Fire Drill would look like close order drill compared the slow motion Loony Tune that passes for what we've got.
Sanity might look like;
1. Determine that spectrum which serves to valuable or significant a purpose to avoid protecting, and declare that sacrosanct. Being able to track water vapor by the way is one of those sacrosanct uses.
2. Give up on that selling the spectrum for fun and profit idea... it was a bad joke then and it hasn't gotten better with time.
3. Put the millitary on a sane leash (they really don't need 50% of the workable spectrum.)
4. Promote the hell out of advanced mutispectrum technologies and count the money.
We really need to get a few folks in the FCC who haven't technological myopia, and have the cojones to push through an agenda based on growing use, and growing technology.
Genda Bendte
ICU's are found in hospitals.
Fiat Lux.
Spectrum allocation is a large, time-varying, multivariable optimization problem. This document is an outline of some of the service requests/requirements, and how they need to mesh with each other, present and future technology availability, and physical limitations (like attenuation due to water at 24 GHz). Note that this document is only U.S. interests; every other country has a similar list, and all have to be coordinated. It's like the guy who goes into a store with three lists: What he wants to buy, what he needs to buy, and what he can afford to buy. Compromise is the name of the game, and reasonable people will make reasonable tradeoffs differently.
The radar this article is discussing is a proposed future use of 24 GHz for collision-avoidance radar in passenger cars. 24 GHz is a popular frequency choice for short-range applications like this specifically because of the atmospheric attenuation. Note that the attenuation at 24 GHz, while higher than at other nearby frequencies, is still relatively low, only a few tenths of a dB per kilometer (although much higher in rain). This makes 24 GHz a good compromise for short-range devices on the Earth's surface, especially low-powered devices with very directional antennas pointed horizontally, away from satellites. (A better choice from this standpoint would be the oxygen absorption band at 60 GHz, and there is indeed another radar band there.)
Meterologists are merely expressing their concern over how their measurements will be corrupted if millions of car radars are in operation, and their cumulative power is enough to be detected by their sensors. My personal opinion, however, is that 24 GHz is too low of a frequency to make a market-successful car radar; the antennas are too big. I think 60 or 77 GHz is a better bet; if so, that would preserve 24 GHz for water vapor measurements.
In general, though, the interests of meterologists and others performing microwave sensing of the earth should be considered in the frequency allocation process; the publicity due to this article is one way of accomplishing this.
It's the same with BPL. Now it's more important to use the frequency spectrum for businesses, despite its critical importance for public services. We will see the consequences in some years; just wait for the coordination in case of a catastrophe failing due to HF pollution, or to miss the prediction of an important storm due to polluted data.
It seems that nowadays there is a sort of inherent "right" to turn anything into business, completely ignoring the impact to the public.
Ok, water vapor sensing is exactly what I did for my master's thesis. I'm going to keep it brief though.
Water vapor has an absorption line centered at 22.235 GHz while liquid water's absorption increases with frequency^1.95. Vapor sensing radiometers do not generally measure at 22.235 GHz because the peak of the absorption line curve is extremely sensitive to pressure. There are points to either side where the curve is insensitive to changes in pressure allowing measurement throughout the entire atmosphere without having to know the pressure profile. That is why the scientists in the article want to keep the 23.6 to 24.0 GHz band for their measurments.
My radiometer measured the emission spectrum at 21.6, 22.235, and 31.6 GHz. 21.6 and 31.6 GHz were the measurements of vapor and liquid water, respectively. 31.6 GHz is a window between the 22.235 GHz vapor line and the group of oxygen lines around 60 GHz. This makes liquid the strongest contributor to the noise temperature at that frequency. The 22.235 GHz was to experiment with. By using 22.235 and 21.6 I tried to see if I could get reasonably similar results even though both frequencies were more sensitive to vapor than liquid. Two close frequencies are measureable using one antenna thereby making the radiometer less expensive and available for more widespread use. I showed that the measurement could be made, but a lot more data needed to be taken to refine the data processing. Enough information was there in the measurements, but there were factors I couldn't account for in the time I had. Hopefully in time, radiometers could become a much more common piece of weather sensing equipment. You can get a lot more data on vapor with a radiometer than you can with a weather balloon, but radiometers are currently expensive and therefore limited in usability. Water vapor is the single biggest driving factor in the weather, we NEED to be able to measure it. Cheaper radiometers would let us get more data and improve weather modeling.
People tend to view weather accuracy on a micro scale, but meteorologists can only work on a macro scale. If you look at satellite images from Canada's weather service, you can see that the city you live in is less than 1/20th the size of a pin-prick relative to a weather system.
When a weather report going out 24 hours into the future says it will rain, it WILL rain... just not perhaps overtop of your little pin-prick. Considering the complexity of weather, realistically how effective can we expect a 3-day outlook to be?
All I'm saying is think big, and you'll realize that meteorology is an inexact science, but is so very valuable as a critical service. Nobody will ever be able to 'stick their head out the window' and have a hope of predicting anything. Meteorologic science deserves a hell of alot more credit than the farmer's almanac.
Well, I am not sure how great we are at predicting the weather now.
As someone who's lived through a half-century of weather prediction technology, I can assure you that it's gotten a LOT better.
There's good reason to believe that, absent some major theoretical breakthrough, there's a "chaos limit" beyond which it can't go - causing the predictions to become unreliable after a few days - the number depending on the stability of the situation. And the current tools are able to both approach the limit and to estimate its location in the current situation.
Broadcast weather reports are NOT an accurate measure of the reliability of prediction technology.
First: They are oversimplified. They claim to tell you exactly what will happen at your spot on the ground - regardless of whether the prediction gives them a basis for doing so. "Scattered showers" might be dead on. But a hundred foot difference in a particular storm cloud's track means your city block get soaked or shined on.
Second: They are show business. "Nice weather, miniscule probability of disaster" will be predicted as disaster - both because it encourages viewers and because they don't want to predict picnic weather and then have the 5% chance of hail hit the jackpot.
IMHO even if they lose their satelite radar's reliability the predictions will get marginally worse but won't go back to what they were in the '50s. Part of the improvement is better data to feed the models. But that radar info is only a tiny part of the new measurement tech. Losing it just means the models sometimes start a bit further off, and deviate sooner. Part of the improvement is better models, and that will stick.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
Michael Powell's Incompetence ... They can't even friggn manage Power and Freq.
It's the policies Powell is currently promoting that brought you cordless phones and WiFi, and is bringing you UWB PANs, WiMAX, and a host of other stuff.
They're rehacking underused spectrum to make it easier to get new stuff working and deployed, and make it available to you sooner. Some is being sold off, some is being released to a commons.
It's an experiment to see which works better. And it's already bearing fruit.
Maybe the commons will work better. Maybe the property model will. But one thing we DO know already: EACH has already gotten more handy tech into consumers' hands than the licensing regime they replaced.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
Car radar is used to for cruise control on Mercedes line of cars which is used to both adjust the throttle and even apply the brake when needed. They are the only ones I know that using radar based cruise control. Infiniti and Lexus both use laser based cruise control. If you have a radar detector you can actually detect people driving with their cruise control on.
Have you ever been to a turkish prison?
At the risk of falling into an "it's not REAL [x]" argument let me disagree with some of your posting.
Sure. Because it never happens that, as one accumulates "territory", one uses it to enforce dictates on those who don't have it, or have less. It never ever leads to a runaway concentration of power -- to higher prosperity for some combined with general misery for most.
Except of course that's exactly what happens.
"Teritory" can be used to enforce an owner's will on those who try to use the owner's property. It can not be used to enforce his will on those who are using their OWN property - even if their property is much smaller. Attempting to control someone else's use of their own stuff is dominance, not territory (even if a piece of property, such as a club, is used as a tool to enforce the dominance).
In the absense of exercise of government power to distort the market or make non-market ownership transfers, no single person or small group can hoard enough of any available type of property to completely dry up the purchasable supply - because the price rises without limit as the supply dwindles. (Such attemts are just a simple way to dissipate a large fortune. You can't get it back by selling off the horde, because selling it depresses the price again.)
Even if someone does accumulate a large enough chunk of something to invonvenience his neighbors, his heirs, or their heirs, may not be as interested in holding it together, so eventually it is broken up and sold off again. Only institutions can accumulate and hold monopolistic real estate or commodity hordes across generations (as they did in the Middle Ages in Europe - until the resulting civil unrest forced the breakup - of the hordes or the institutions). This is why the US government (the results of one of the earliest of those revolutions) has bans on perpetuities and entailments. (Corporations can also span generations, but they can also be broken up from outside. Non-profits, though, seem to be trying to recreate the problems of the middle ages.)
Unfortunately, governments themselves are authorities, and their codification of the rules of property is an exercise of authority. As a result, property laws tend to be a mix of encoding of territorial and authoritarian mechanisms.
If they JUST encoded territory, for instance, there'd be no emminent domain. There'd have been no sweetheart deals for the railroads in the 18th century, stealing 10-mile wide swaths through people's farms adjacent to the route they picked as they built across the plains. Anyone wanting to build a road, bury a pipeline, run a power line, or do any of the things that currently excuse over 500 agencies bullying people off their land, would have to buy options from landowners until he accumulated a route.
Property taxes are another deviation. If it's YOURS, why do you have to anually pay a significant fraction of its value to the government, which will take the property from you if you don't pay up? That's dominance, not territory. And it's a significant factor in raising the price of housing beyond the reach of the lower income.
Then there's zoning/land use planning. In the name of "quality of life" and "preventing urban sprawl" these severely curtail the availability of real property and again raise its price - protecting the interests of current owners at the expense of prospective home buyers and builders. Pikers compared to "wilderness areas", of course.
Housing codes raise the price again. Contractor licensing ditto. Inspections. All "for your own good" of course, and the government knows what that is better than you, eh? Dominance.
Government "programs": "Urban renewal" - kick the poor out of their houses and sell the land at below market price to developers, who may build walled communities to sell to the rich, or stadiums where only the rich can afford a seat. Or just kick 'em out and let the buildings rot, until the rats and criminals move in. "Housing and Urban D
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
You can see the clouds. But it gets hard to figure out what the clouds are made of. Water vapor has a resonant absorbtion line at 22.235 Ghz and liquid water has a broad non-resonant absorbtion spectra (which is wby microwave ovens work). The pressure in the atmostphere broadens the lines, so if you look at one frequency you can "see" lower in the atmosphere than you can at another nearby frequency. The inversion problem of getting temperature and liquid water/water vapor profiles out of this junk is non-trivial. Your visual stuff and IR just sees the cloud tops and little more. IR can get profiles up to the cloud top and then it is a dead stop. Visual does not get profiles period. Since the amount of energy in the atmostphere is in no small measure bound up with the amount of water vapor that is in it, you better see below the tops of the clouds. Without that, a big fat hot cumulus and a cold thin cirris cloud look an awful lot like each other. Optical is useless for detecting sea surface conditions (wind speed). The "brightness" of the ocean surface is a function of wind speed and foam coverage. Of course you would need wind speed for anything now would you? Same thing goes with the depth of snow. Snow several feet deep reflects differently on land than snow 1/10 of an inch deep. Last time I looked, there was an issue of the heat necessary to melt the junk and the runoff from it that was of more than passing interest to a lot of folks.
One of the major problems with weather prediction, besides the non-linear chaotic stuff, is that you have to characterize a pretty rich field of data points before you turn on your finite mesh predictor. Sadly, most of the world does not chuck weather balloons up and/or is covered with ocean. Placing a call to that spot three miles offshore is not an option. Even if it is, you still have to understand much more about what the vertical profile of the weather is above the spot than just a simple rain/no rain analysis.
I dare say, that there is more than a little bit of a problem with what they are talking about. Of course if you care to live in the bad old days of the Galveston Hurricane or the Hurricane of 38, I guess there is no stopping you. But please learn a bit about weather forcasting before you decide that this is fud. It is anything but.