One problem is that many stations are on the air, but running at low power. One local station has 4 MW ERP on their analog channel and 1 kW ERP on their digital channel.
Television. at least in the United States, is a huge spectrum hog. The UHF TV band used to suck up everything from 470 MHz to 890 MHz. The FCC created the 800 MHz cellular and two-way radio bands by chopping off the top of the UHF TV band.
I know how at least some of them work. My point was that every stage of the system needs to have sufficient dynamic range to handle weak and strong signals at the same time. With a conventional dish antenna, if there is a strong source of interference, 10 degrees off-axis, I don't care. It never makes it to the feed horn of the antenna. With a phased array system, I have to look at the antenna pattern of each element to determine what signals will get into the system, even if they are later eliminated when the elements' signals are combined.
Your problem isn't the $695 a session actor voicing Officer Payday, it's the management of your company, who view their employees as serfs.
Too many employees have the mentality of a prisoner in a Soviet gulag. They would prefer to see everyone get moldy bread and cabbage soup, rather than see another prisoner get better rations.
Each telescope is going to have a pre-amp, down-converter and digitizer, all of which have a finite dynamic range. Let's say that it is 40 dB. You are trying to examine a weak signal source, say -130 dBm. At the same time, you are receiving an interfering signal with a strength of -80 dBm. This wipes out the weak signal before it has the chance to reach the combiner. Even worse, if the system is overloaded by a strong signal, it can go nonlinear and all of the data is useless.
Think of it this way. The radio astronomer's antenna is pointed at the sky. It doesn't see radiation sources on the ground. It does see the cell phone in the airplane that is flying through its field of view.
The wavefront, at any given time, is approximated by the surface of a sphere. Think of it as a series of bubbles, each expanding at the speed of light.
The RF noise from all of the on-board equipment is going to depend greatly on their transmitter design. It isn't difficult or expensive to greatly reduce out-of-band noise with some simple passive filters.
The FCC could also tighten up emissions standards for cellular phones. The problem is that the phones are so damn small. Are there any space-efficient filters that provide the out-of-band attenuation of a good cavity filter?
It was probably the RF11. It was huge, filled up a whole rack. I used to use a PDP-11/20 that used an RF11 for its system disk. It had enough space to store the important parts of RT-11.
It wouldn't work. At the small scales used in modern hard drives, you can't park a head over a track and do I/O. It's more like one of those old arcade racing games, where the road swerves from side to side as you travel forward down the race track. The drive electronics have to continuously adjust the head position to keep it flying down the center of the track. Optical drives are even worse, they have to move the head assembly up-and-down and side-to-side to keep the laser focused on the track.
Part of it is because he targeted the federal government, which means he violated federal laws and will be tried in a federal court. Sentences are usually substantially longer in the federal system.
If you are going to commit a crime, don't do it on federal property or under circumstances that trigger federal jurisdiction. The federal prosecutors and courts have the time and resources to make an example of you.
The Department of Energy is part of the federal government. Why were they asking the State of Washington for a permit? The federal government has no obligation to obey state laws.
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We'd rather have them rioting in the streets.
In the long run, the cable companies are planning to eliminate all of the analog channels.
They tried that with AM Stereo. It was a disaster.
One problem is that many stations are on the air, but running at low power. One local station has 4 MW ERP on their analog channel and 1 kW ERP on their digital channel.
Television. at least in the United States, is a huge spectrum hog. The UHF TV band used to suck up everything from 470 MHz to 890 MHz. The FCC created the 800 MHz cellular and two-way radio bands by chopping off the top of the UHF TV band.
It's multiplexed in with the digital video.
I know how at least some of them work. My point was that every stage of the system needs to have sufficient dynamic range to handle weak and strong signals at the same time. With a conventional dish antenna, if there is a strong source of interference, 10 degrees off-axis, I don't care. It never makes it to the feed horn of the antenna. With a phased array system, I have to look at the antenna pattern of each element to determine what signals will get into the system, even if they are later eliminated when the elements' signals are combined.
Too many employees have the mentality of a prisoner in a Soviet gulag. They would prefer to see everyone get moldy bread and cabbage soup, rather than see another prisoner get better rations.
How much time do they spend practicing, preparing, going to auditions, and hustling for work?
Each telescope is going to have a pre-amp, down-converter and digitizer, all of which have a finite dynamic range. Let's say that it is 40 dB. You are trying to examine a weak signal source, say -130 dBm. At the same time, you are receiving an interfering signal with a strength of -80 dBm. This wipes out the weak signal before it has the chance to reach the combiner. Even worse, if the system is overloaded by a strong signal, it can go nonlinear and all of the data is useless.
You are assuming that the preamps and receivers in the radio telescopes have infinite dynamic range.
Think of it this way. The radio astronomer's antenna is pointed at the sky. It doesn't see radiation sources on the ground. It does see the cell phone in the airplane that is flying through its field of view.
The wavefront, at any given time, is approximated by the surface of a sphere. Think of it as a series of bubbles, each expanding at the speed of light.
http://www.badastronomy.com/bad/misc/dark_side.htm l
The RF noise from all of the on-board equipment is going to depend greatly on their transmitter design. It isn't difficult or expensive to greatly reduce out-of-band noise with some simple passive filters.
Here's your ticket for the "B" Ark. Don't be late.
Radio astronomers also use those frequencies, so there is more involved than SETI, or some group's software.
The FCC could also tighten up emissions standards for cellular phones. The problem is that the phones are so damn small. Are there any space-efficient filters that provide the out-of-band attenuation of a good cavity filter?
I bought a Mac to get away from Wintel crap.
It was probably the RF11. It was huge, filled up a whole rack. I used to use a PDP-11/20 that used an RF11 for its system disk. It had enough space to store the important parts of RT-11.
It wouldn't work. At the small scales used in modern hard drives, you can't park a head over a track and do I/O. It's more like one of those old arcade racing games, where the road swerves from side to side as you travel forward down the race track. The drive electronics have to continuously adjust the head position to keep it flying down the center of the track. Optical drives are even worse, they have to move the head assembly up-and-down and side-to-side to keep the laser focused on the track.
If you are going to commit a crime, don't do it on federal property or under circumstances that trigger federal jurisdiction. The federal prosecutors and courts have the time and resources to make an example of you.
It's the contractor's fault when the customer doesn't have a clue and changes the requirements on a daily basis?
The Department of Energy is part of the federal government. Why were they asking the State of Washington for a permit? The federal government has no obligation to obey state laws.
Whether or not someone's copyright has been infringed, it is plagiarism.