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macpacheco (1764378) writes "For ages, high accuracy GPS meant using a mix of civilian and military signals. In order to obtain high accuracy GPS positioning (better than 2 meters) receiver must know local ionosphere corrections. This requires two GPS signals at a minimum, the difference between both is used to calculate ionospheric corrections which is then applied to either one. However since GPS doesn't offer two usable civilian signals, a technique known as semi-codeless was devised, that calculates ionosphere corrections by using the two military encrypted signals L1P(Y)+L2P(Y), then applies the iono corrections to the civilian L1 C/A signal, however the military was never to fond of that usage, since it limits what changes they can do with the military signals. Specially changes in power levels. Since September 26, 2005 GPS satellites capable of broadcasting the L2C (2nd civilian signal) and since May 2010 GPS satellites capable of broadcasting the L5 (3rd civilian signal, usable for aviation) have been launched, however those signals are still not fully usable. Today those signals were enabled in a pre operational format meaning:
1 — All messages required for full L2C and L5 utilization are broadcast
2 — L5 signals are broadcast with an alert flag (not usable), L2C is broadcast without an alert flag
3 — L2C/L5 almanac and ephemeris will be updated about twice a week, while regular L1 C/A updates happen typically twice a day, so L2C and L5 signals will be less accurate in this phase
However this means there is no technical excuse for GPS equipment manufacturers to finalize their L2C and L5 offerings, since they now have a complete signal to test against, and right after GPS satellites have received an upload they should have similar accuracy as L1 C/A. This should continue for the next few years, until the new GPS control segment, OCX comes online, OCX block 1 is needed for full L2C capabilities and OCX block 2 is needed for full L5 capabilities. Notice that it will take at least another 12 GPS launches for L2C to reach a state known as FOC (full operational capability), meaning that are enough satellites with L2C capability for L2C to be usable for standalone positioning and it will take another 19 GPS launches for L5 to reach FOC as well." Link to Original Source top
macpacheco (1764378) writes "Very interesting to read a clearly Big Oil sponsored article, and then read all comments, not a single comment supporting the writer's stupid, short sighted views.
Forbes needs to first write articles scathing the trillions of dollars the Oil + Coal industry got in subsidies over the last 50yrs before they be allowed to try to criticize the solutions to our pollution problems !" Link to Original Source top
macpacheco (1764378) writes "Another critical fact neither the GOP nor the Dems address which is critical to economical recovery: In 1970, a business needed as many as 10x more employees to accomplish the same administrative tasks (invoicing, payroll, accounting, IT, production planning, inventory), as today. After the PC revolution, businesses needed less people to do the same, they got fired, but the services sector re-used them for other jobs, many started businesses of their own. However their a limit to how many people large businesses can fire until the economy can't re cycle them. The current economy is getting too productive. B2B and B2C processes are further reducing the number of employees needed to get the job done. Eventually there will be next to none clerical employees, forklift jobs get automated, robots take over production. How can the economy re accomodate that labor force ? The services sector need customers ! Eventually unemployment will rise. Don't we need to have some limits to automation to ensure that manufacturing actually hires ? If the whole economy hires 10% of what it did in the pre PC age, how is full employment possible ? That's a difficult question no sides are willing to answer." top
Mitt Romney, conservative/moderate or just plain liar ?
macpacheco (1764378) writes "After listening to the 47% tape, following the Republican primaries and the first month of all out electoral campaign, I'm puzzled.
Is Romney just a flip flopper, or is he a pathological liar ? People that tell you what they want you to hear, just because they can get away with it, no matter how untrue, are the worse type of politician and human beings on the planet.
I'm not from the US (I'm from Brazil), if I was a US citizen, I'd be an independent, I would vote for Obama not because I like him, but instead because I think the current generation of Republicans are just 10 times worse !
I do have an agenda, I'm a pragmatic environmentalist, and I'm against all kinds of corporative inefficiency, specially the government type of corporative inefficiency. The Dems have their faults, but the GOP fails to show any way that they actually mean to do the positive side of their agenda." top
macpacheco (1764378) writes "Atomic clocks for a long time have been a research lab item, used in production environments only in high budget, ultra performance demanding environments. Their high power consumption, 4U size and weight also didn't help. Chip scale atomic clocks (CSAC) have been a promise for a long time. They're finally here. Typical atomic clocks cost tens of thousands of dollars each, this first generation CSAC costs US$ 1400 in small quantities. 1 cu inch volume (16 cc), 115mW power consumption (down about 1000 fold), and just 35 grams weight, will make them more interesting than current GPS based frequency standard. They're called frequency standard, because 99% of the time someone needs an atomic clock, it's not to actually track time (day, hour, minutes, seconds, milliseconds), its used instead a replacement for quartz crystal oscillators, mainly transmitting and receiving radio signals, synchronizing telecommunications equipment. This atomic clock claims to be about 10000 times more accurate than typical quartz based oscillators. This is very exciting, as it will enable better 4g/WiMax/... base stations, better ultra high speed networking equipment, and will help tremendously in GPS augmentation solutions like WAAS, EGNOS, DGPS. Having an atomic clock on a GPS receiver works like an extra GPS satellite." Link to Original Source