<HTML dir=ltr><HEAD><TITLE>Re: [Proj] Scale factor for Transverse Mercator</TITLE>
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<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=2>Originally, the military did not expect Academics to figure out a way to get around the single point-positioning mode of the NAVSTAR (GPS) system. The DoD figured that <STRONG><EM>on paper</EM></STRONG>, dithering the signal would not allow our combatants to utilize our GPS system as guidance for their ordnance against us.</FONT></DIV></DIV>
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<DIV dir=ltr><FONT size=2>It was expected that dithering the signal would/could increase the "circle of uncertainty" to 100-300 meters, thus rendering GPS unusable to our enemies in a conventional, non-nuclear-warhead war. Remember, NAVSTAR was originally conceived in the early 1970s, and was not envisioned as ever being useable for the civilian community - <STRONG>at that time</STRONG>.</FONT></DIV>
<P><FONT size=2>Remember it was Niels Bohr that said, "Prediction is a pretty tough thing to do, especially in the future."</FONT></P>
<P><FONT size=2>Cliff Mugnier</FONT></P>
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<DIV dir=ltr><FONT face=Tahoma size=2><B>From:</B> proj-bounces@lists.maptools.org on behalf of Gerald I. Evenden<BR><B>Sent:</B> Wed 10-Sep-08 14:37<BR><B>To:</B> PROJ.4 and general Projections Discussions<BR><B>Subject:</B> Re: [Proj] Scale factor for Transverse Mercator<BR></FONT><BR></DIV>
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<P><FONT size=2>On Wednesday 10 September 2008 3:17:50 pm Clifford J Mugnier wrote:<BR>> The State Plane Coordinate Systems were<BR>...<BR>> The Scale Factor at a Point maximum of<BR>> 1:2,500 at the Central Meridian was considered OK for Fire Control because<BR>> for this application, the 6° Zones were limited in longitudinal extent<BR>> because of the convergence angle between Grid North and Geodetic North -<BR>> soldiers don't really care that much about the difference between Grid<BR>> Distance and Geodetic Distance ... the blast radius of a 155mm Howitzer<BR>> shell takes care of that little "problem."<BR><BR>Under the same logic, I could never understand the reason for fuzzing the GPS<BR>signals because what difference does a few meters mean with the blast radius<BR>of an H-bomb?<BR><BR>The wonders of the military mind.<BR><BR>If one is laying in air burst of with 155 a little fuzz will not make much<BR>difference because you are probably doing a carpet barrage anyway. But if<BR>you are trying to knock out just one house in a city block (like they do with<BR>the smart bombs) then ... . Curious about the electronics in some of the<BR>newer artillery pieces. New command and control is something else from what<BR>little I've seen and heard.<BR><BR>--<BR>The whole religious complexion of the modern world is due<BR>to the absence from Jerusalem of a lunatic asylum.<BR>-- Havelock Ellis (1859-1939) British psychologist<BR><BR>_______________________________________________<BR>Proj mailing list<BR>Proj@lists.maptools.org<BR><A href="http://lists.maptools.org/mailman/listinfo/proj">http://lists.maptools.org/mailman/listinfo/proj</A><BR></FONT></P></DIV></BODY></HTML>