Posts: 11,030
Threads: 751
Joined: Sep 2012
Where is the "Hawaii businesses"?
I provided an example and had hoped readers would suggest other local business applications:
"Probably helpful for any number of delivery based businesses, for instance, getting your pizza delivered as quickly as possible... Any others?"
With your extensive knowledge of "hundreds and thousands" of spaced based telescopes and other satellites launched every year, I'd expect you could provide us with more examples than anyone. Or do those "thousands" of satellites sent into orbit yearly only take jobs away from the Big Island, by making telescopes here obsolete? Perhaps you believe future advances will take even more jobs away from Hawaii? Are we incapable of integrating space based technologies into our daily lives?
- Be pleasant to inefficient workers; give them undeserved promotions. - Work slowly. - Refer all matters to committees for "further study and consideration. - Hold conferences. - Make travel as inconvenient as possible. - Haggle over precise wordings of communications. - Advocate “caution.” Be “reasonable” and avoid haste. (Excerpts from the WWII OSS Simple Sabotage Manual)
"I'm at that stage in life where I stay out of discussions. Even if you say 1+1=5, you're right - have fun." - Keanu Reeves
Posts: 664
Threads: 67
Joined: Mar 2016
quote:
Originally posted by HereOnThePrimalEdge
Are GPS signals then handed off from one satellite to another like cell phone calls from one tower to another?
Do GPS satellites circle the earth closer than a geosynchronous orbit in order to provide a stronger signal to automotive and small handheld GPS devices? Or for another reason?
I could tell you more than you
ever wanted to know about the GPS system. Essentially they have atomic clocks in them. Each satellite broadcasts a pseudo-random (PNR) code specific to that satellite. They are all at the same frequency and receivers "despread" or decode the timing from each satellite depending on the PN code.
The receiver measures the time difference between the received signals from at least 4 satellites (for 3-d solution) and uses a built in atlas of each satellites position in orbit to compute the receivers location.
The satellites are constantly monitored for errors and timing corrections are broadcast from the ground station to each individual satellite. The most interesting correction that needs to be made include time offsets for relativity. See this for a map of stations providing timing corrections:
http://www.gps.gov/systems/gps/control/
In addition there are ground stations that broadcast additional GPS corrections for higher accuracy like around airports (for planes). This is called DGPS or differential GPS
https://en.wikipedia.org/wiki/Differential_GPS
Also there are very high end GPS systems that can get sub-centimeter accuracy using a technique called Carrier-Phase GPS. They can take 15-30 minutes to acquire this fine of a position, but it is often use in surveys.
The satellites are in LEO or low earth orbit.
quote:
Another issue we wrestled with is which satellite orbits to use. We did not want to be in geostationary or geosynchronous orbits. The reason was these alternatives would force us to deploy ground stations on the other side of the globe, whereas, by putting them in some orbit that periodically passed across the United States, you could update the knowledge of where they were and what time it was on the satellite, then store that information in the satellite and continue to broadcast as it went around the Earth. That is the fundamental way we ended up with twelve-hour orbits. We also wanted to be reasonably high because we didn’t want the orbits significantly disturbed by the atmospheric drag. At the same time, by going high you had more visibility, more coverage on the Earth. So with an Earth coverage antenna and suitable power densities on the Earth, you ended up with the ability of twenty-four satellites to provide very solid, total Earth coverage.
Posts: 192
Threads: 10
Joined: Jan 2009
Aloha Eric: A stellar presentation even if you withheld much more than you disclosed. More and more helpful, is Eric 1600. Perhaps we ought to upgrade him to 1750?
-dwajs
-dwajs
Posts: 10,236
Threads: 345
Joined: Apr 2009
Just a small correction to Eric's great post. The GPS satellites are in medium earth orbit (MEO), not low earth orbit (LEO). LEO encounters problems with interaction with the earth's atmosphere so orbital adjustments are needed, whereas MEO is above those effects although gravitational effects still require adjustments, just not as often. MEO also allows the satellites to orbit two times a day rather than several times a day.
Posts: 3,204
Threads: 108
Joined: Jun 2010
I'm thinking advances in satellites, solar efficiency, and radio technology could one day enable 100% broadband coverage of the planet. Also power generation and storage in every home.
The implication for Hawaii would be invisible infrastructure. No more power lines, cable lines, phone lines, and poles messing up beautiful views. Less need to commute and pollute. A return to nature, thanks to technology.
Posts: 5,640
Threads: 101
Joined: Dec 2008
Who would sign a petition to bring back the Space Base?
Posts: 1,930
Threads: 71
Joined: Jun 2012
It was a real stretch to jumble multiple topics together and call it Puna related.
Here is mine. PUNA - EXOPLANET!
This part of Hawaii is so great for the years ahead, massive advances while 99% stay totally clueless. South Puna is firmly fixed in time to 1971, with many parts of the population wanting to go back to 900 AD Europe, other parts wanting a do-over of 1779 AD, meeting Captain Crook with a luau pit already dug for long pig, a few people thinking they were sent from the future to kill Sarah Conner, other assorted types that characterize Puna ambiance.
Uber is testing self driving cabs in San Francisco. Nvidia has a GPU-accelerated car AI and joined with Baidu, who is poised for an electric taxi entry into the US market. It's more likely these developments will be seen in south Puna over the next few years. If rental car agencies also start having the capability of dispatching self-driving electric taxi cars, that will change multiple businesses quickly, mainly eliminating taxi businesses. The future ahead is many job titles becoming obsolete. It won't be noticed that much in south Puna, most people are self employed or retired or have a trust fund.
*Japanese tourist on bus through Pahoa, "Is this still America?*
*Japanese tourist on bus through Pahoa, "Is this still America?*
Posts: 10,236
Threads: 345
Joined: Apr 2009
"This part of Hawaii is so great for the years ahead, massive advances while 99% stay totally clueless. South Puna is firmly fixed in time to 1971, with many parts of the population wanting to go back to 900 AD Europe, other parts wanting a do-over of 1779 AD, meeting Captain Crook with a luau pit already dug for long pig, a few people thinking they were sent from the future to kill Sarah Conner, other assorted types that characterize Puna ambiance."
Who is Sarah Conner?
Posts: 3,204
Threads: 108
Joined: Jun 2010
Yeah right, TomK! What model are you anyway? Cyberdyne T-800?
http://www.imdb.com/title/tt0088247/
Posts: 10,236
Threads: 345
Joined: Apr 2009
Thanks, randomq! Never been a big fan of science fiction; I think I saw that movie in the mid-80s and for some reason, that name just didn't seem to stick in my memory!
