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Index of Subjects
Index of Subjects --Apple-Mail-594-713663003 Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit In addition to GPS, the Russians have a global navigation satellite system called GLONASS the "GLObal NAvigation Satellite System" in English) which began its implementation in 1982. After the end of the Soviet Union it fell into disrepair but commencing in 2001 the Russian government, in partnership with the Indian government, has been rebuilding the system so that it now consists of 20 satellites and covers 80% of the globe. There are plans to launch an additional 10 satellites so that by 2011 they will have achieved 100% coverage of the planet. As of May 18, 2007 this system is now available free of charge to civilians. It has a horizontal accuracy of 50-70 meters. http://en.wikipedia.org/wiki/GLONASS The European Union and the European Space Agency are also working on a global navigation satellite system called Galileo which is slated to become operational in 2013. There will be a free Open Service (OS) available to everyone which will have a horizontal accuracy of < 4 m and an encrypted Commercial Service (CS) which will offer a horizontal accuracy of < 1 m! This signal can then be combined with signals from ground stations to bring the accuracy to < 10 cm. Astonishing! http://en.wikipedia.org/wiki/Galileo_positioning_system The Chinese also want to build a system called Compass, but it seems to be mostly in a testing planning stage. Only one satellite has been launched and I don't know if there is even a projected date by which it might be operational. http://en.wikipedia.org/wiki/Compass_navigation_system Cheers! Christopher Majka (ancient mariner) On 20-Oct-09, at 10:08 AM, Hubcove@aol.com wrote: > As Chris said, the degrading of the GPS position was very much a US > policy, apparently primarily to degrade targeting information. The > way major manufacturers got around the problem was by marketing > Differential GPS. Receivers in significant navigation locations, > Chebucto Head for example, received the GPS signal, compared it to > the actual position of the receiver and transmitted the correction > to shipborne receivers on a frequency of around > 300khz. Prior to that, while the absolute accuracy of GPS was > superior to Loran, the relative accuracy with Loran was very high. > In other words, if you put something in the water and noted the > Loran reading, it would still be very close to the same reading when > you came back, assuming of course it was anchored. Loran errors can > be quite large, but are generally constant. > > Peter Stow > (ancient sea captain} > Hubbards --Apple-Mail-594-713663003 Content-Type: text/html; charset=US-ASCII Content-Transfer-Encoding: quoted-printable <html><body style=3D"word-wrap: break-word; -webkit-nbsp-mode: space; = -webkit-line-break: after-white-space; "><div>In addition to GPS, the = Russians have a global navigation satellite system called GLONASS = the "GLObal NAvigation Satellite System" in = English) which began its implementation in 1982. After the end of the = Soviet Union it fell into disrepair but commencing in 2001 the Russian = government, in partnership with the Indian government, has been = rebuilding the system so that it now consists of 20 satellites and = covers 80% of the globe. There are plans to launch an additional 10 = satellites so that by 2011 they will have achieved 100% coverage of the = planet. As of May 18, 2007 this system is now available free of charge = to civilians. It has a horizontal accuracy of 50-70 = meters.</div><div><br></div><div><a = href=3D"http://en.wikipedia.org/wiki/GLONASS">http://en.wikipedia.org/wiki= /GLONASS</a></div><div><br></div><div>The European Union and the = European Space Agency are also working on a global navigation = satellite system called Galileo which is slated to become operational in = 2013. There will be a free Open Service (OS) available to everyone which = will have a horizontal accuracy of < 4 m and an encrypted Commercial = Service (CS) which will offer a horizontal accuracy of < 1 m! This = signal can then be combined with signals from ground stations to bring = the accuracy to < 10 cm. = Astonishing! </div><div><br></div><div><a = href=3D"http://en.wikipedia.org/wiki/Galileo_positioning_system">http://en= .wikipedia.org/wiki/Galileo_positioning_system</a></div><div><br></div><di= v>The Chinese also want to build a system called Compass, but it seems = to be mostly in a testing planning stage. Only one satellite has been = launched and I don't know if there is even a projected date by which it = might be operational.</div><div><br></div><div><a = href=3D"http://en.wikipedia.org/wiki/Compass_navigation_system">http://en.= wikipedia.org/wiki/Compass_navigation_system</a></div><div><br></div><div>= Cheers!</div><div><br></div><div>Christopher Majka</div><div>(ancient = mariner)</div><br><div><div>On 20-Oct-09, at 10:08 AM, <a = href=3D"mailto:Hubcove@aol.com">Hubcove@aol.com</a> wrote:</div><br = class=3D"Apple-interchange-newline"><blockquote type=3D"cite"> <div = style=3D"FONT-FAMILY: Arial; COLOR: #000000; FONT-SIZE: 10pt" = id=3D"role_body" bottommargin=3D"7" leftmargin=3D"7" rightmargin=3D"7" = topmargin=3D"7"><font id=3D"role_document" color=3D"#000000" size=3D"2" = face=3D"Arial"> <div><font size=3D"3">As Chris said, the degrading of = the GPS position was very much a US policy, apparently primarily = to degrade targeting information. The way major manufacturers got around = the problem was by marketing Differential GPS. Receivers in significant = navigation locations, Chebucto Head for example, received the GPS = signal, compared it to the actual position of the receiver and = transmitted the correction to shipborne receivers on a frequency of = around</font></div> <div><font size=3D"3">300khz. Prior to that, while = the absolute accuracy of GPS was superior to Loran, the relative = accuracy with Loran was very high. In other words, if you put = something in the water and noted the Loran reading, it would still be = very close to the same reading when you came back, assuming of course it = was anchored. Loran errors can be quite large, but are generally = constant.</font></div> <div><font size=3D"3"></font> </div> = <div><font size=3D"3">Peter Stow</font></div> <div><font = size=3D"3">(ancient sea captain}</font> &l