I don't agree that this is being sensationalized. This is a sensational accomplishment and I think the general public understands this. The fact that our last two attempts had failed, and the Beagle 2 failed, and the Japanese spacecraft failed really drives home the point that what JPL is doing is hard, hard stuff.
I do think that some journalists drive the "life on Mars" angle too heavily, but then I don't expect the 10 o'clock news to have the same cautious scientific approach as NASA.
As to the politics, well, NASA is a government agency. It is a political creation and it has to fight for its money just like everyone else. So it doesn't surprise me when they try to get these super high definition images out. As a supporter of the space program, I wish NASA did a better job with their PR. Like they said in The Right Stuff, "No bucks, no Buck Rogers."
This is exactly right. The press conference from yesterday can be seen on CSPAN. The reporters asked about colors a couple of times. There are a number of filters and the coloring will depend in part on which filter an image was taken with. NASA also said that since they know the spectral characteristics of Mars, they can take a picture with a near-infrared wavelength (e.g. 750nm) and alter the image so that it would appear as in a visible wavelength.
Actually, think DWDM systems. In the Metro market, it is common to have 32 channel systems. With each channel putting out +6 dBm and amplifiers in the mix, you can easily get to 27 dBm and above. Long-haul DWDM systems can generate even more power.
You would probably be surprised at how many amplifiers are used in applications that are within a city.
I'm amazed that there is nothing here about Tcl. I use everything from shell to C to Perl, but Tcl is consistenly one of my favorite languages. I don't know why it doesn't get more respect.
Anyway,
Activestate is a great place to start, especially the cookbook. The weekly Tcl-URL is published at Dr Dobbs. The Tcl Developer Xchange also has a lot of resources. Most of the major Tcl developers hang out in comp.lang.tcl (probably one of the most civil newsgroups there is). Quick answers to questions are always available there.
They use specialized test sets for this. These test sets generate pseudo-random data sequences. These things are extremely common. For $100K you can get a 10Gbs (OC-192) test box from Agilent (I have two). Lucent would have used a 40Gbs box. Those aren't very common now, but I'm sure they are available for enough money. Anyway, buy 64 of those test sets and simply feed that data into the mux device. Optical muxes are generally passive devices so there is no processing involved there. There is nothing difficult about generating this much data. It is just a matter of money.
This is not about processing power. Most telecom devices use embedded processors (think 50-100 MHz motorola processors), FPGAs, and/or ASICS. The processors just setup and control the real hardware. They generally don't see the data at all.
This type of equipment adds bandwidth capacity to the core transport networks. This has little to do with how a site like Yahoo, etc gets its bandwidth (the access side). Given the amount of dark fiber out there, it is unlikely that bandwith costs are related to lack of supply in the core. It is because providing multi Gb/s to a customer is expensive. Lack of good multicasting on the internet also increases their bandwidth usage.
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I don't agree that this is being sensationalized. This is a sensational accomplishment and I think the general public understands this. The fact that our last two attempts had failed, and the Beagle 2 failed, and the Japanese spacecraft failed really drives home the point that what JPL is doing is hard, hard stuff.
I do think that some journalists drive the "life on Mars" angle too heavily, but then I don't expect the 10 o'clock news to have the same cautious scientific approach as NASA.
As to the politics, well, NASA is a government agency. It is a political creation and it has to fight for its money just like everyone else. So it doesn't surprise me when they try to get these super high definition images out. As a supporter of the space program, I wish NASA did a better job with their PR. Like they said in The Right Stuff, "No bucks, no Buck Rogers."
This is exactly right. The press conference from yesterday can be seen on CSPAN. The reporters asked about colors a couple of times. There are a number of filters and the coloring will depend in part on which filter an image was taken with. NASA also said that since they know the spectral characteristics of Mars, they can take a picture with a near-infrared wavelength (e.g. 750nm) and alter the image so that it would appear as in a visible wavelength.
Actually, think DWDM systems. In the Metro market, it is common to have 32 channel systems. With each channel putting out +6 dBm and amplifiers in the mix, you can easily get to 27 dBm and above. Long-haul DWDM systems can generate even more power.
You would probably be surprised at how many amplifiers are used in applications that are within a city.
I'm amazed that there is nothing here about Tcl. I use everything from shell to C to Perl, but Tcl is consistenly one of my favorite languages. I don't know why it doesn't get more respect.
Anyway, Activestate is a great place to start, especially the cookbook. The weekly Tcl-URL is published at Dr Dobbs. The Tcl Developer Xchange also has a lot of resources. Most of the major Tcl developers hang out in comp.lang.tcl (probably one of the most civil newsgroups there is). Quick answers to questions are always available there.
They use specialized test sets for this. These test sets generate pseudo-random data sequences. These things are extremely common. For $100K you can get a 10Gbs (OC-192) test box from Agilent (I have two). Lucent would have used a 40Gbs box. Those aren't very common now, but I'm sure they are available for enough money. Anyway, buy 64 of those test sets and simply feed that data into the mux device. Optical muxes are generally passive devices so there is no processing involved there. There is nothing difficult about generating this much data. It is just a matter of money.
This is not about processing power. Most telecom devices use embedded processors (think 50-100 MHz motorola processors), FPGAs, and/or ASICS. The processors just setup and control the real hardware. They generally don't see the data at all.
This type of equipment adds bandwidth capacity to the core transport networks. This has little to do with how a site like Yahoo, etc gets its bandwidth (the access side). Given the amount of dark fiber out there, it is unlikely that bandwith costs are related to lack of supply in the core. It is because providing multi Gb/s to a customer is expensive. Lack of good multicasting on the internet also increases their bandwidth usage.