Date: Fri, 25 Sep 2009 09:58:09 -0700 [11:58:09 AM CDT]
From: "John Lear"
To: "'Jack & Sue White'"
Cc: [Show addresses - 28 recipients]
Subject: RE: GLOBAL POSITIONING FOR WTC LOCATION USED HEAVILY DURING ATTACK PERIOD!
GPS in a commercial airliner is entered in degrees, minutes and tenths of a minute.
It looks like this: N 40̊ 42’ .7 W 74̊ 0’ .7”
Where 40 is the degrees of latitude 42 is the minutes and .7 is the seconds (42 seconds) And .7 means seven tenths of one minute. For Longitude 74 degrees 0 minutes and .7 means seven tenths of one minute.
Commercial aircraft do not use 60 seconds or portions thereof because that kind of accuracy is not needed for flight. Commercial aircraft use tenths of a minute instead.
The approximate technical latitude and longitude for the north tower is (approximately):
North 40 degrees 42 minutes 42 seconds and West 74 degrees 0 minutes 45 seconds.
So in commercial airliners the approximate lat/long of the North Tower is North 40̊ 42 ‘ .7 (7/10’s of a minute) and West 74̊ 0’ .7 (7/10’s of a minute).
One minute of latitude at the north tower is 1 mile so 7/10’s of one minute or 4214 feet.
One minute of longitude at the north tower is 4,500 feet. So 7/10’s of one minute is 3150 feet.
So if you entered into your GPS for the north tower you would be entering:
North 40 degrees 42 minutes 4,214 feet. (.7)
West 74 degrees 0 minutes 3,150 feet. (.4)
So in latitude the closest you are going to get to the North Tower target is 602 feet
(one tenth of 6020) and the closest in longitude is going to be 450 feet (one tenth of 4500 feet).
So to hit a target dead on in the center of a 208 feet wide building with standard GPS is utterly impossible.
The military uses 60 seconds for the third digit of latitude and 60 seconds for the third digit of longitude for more accuracy, but commercial airliners didn’t have that capabilitity until after 2001 when WAAS became available but were limited to tenths of a minute for both latitude and longitude.
So lets work a problem using 60 seconds for the third digit in both latitude and longitude. Latitude entry would be 70̊ 42’ 42” and longitude 74̊ 0’ 45”. One
sixtieth of one minute would give you an accuracy of 100 feet in latitude and 75 feet in Longitude. Still not accurate enough to hit a 208’ wide building exactly where you wanted.
Leading GPS Software Suggests Superior Augmented GPS Service At WTC During 9/11 Attacks
Submitted by Aidan Monaghan on Thu, 09/24/2009 - 10:25am. 911 Blogger.com
As the aircraft attacks of September 11, 2001 unfolded at the World Trade Center, virtually maximum augmented GPS positioning quality for the entire daylight period was provided to the geographic coordinates for the World Trade Center.
GPS position quality is strongly affected by the number of GPS satellites visible to a GPS receiver and the orbital geometry of GPS satellites with respect to a GPS receiver. Augmented GPS signal receivers and Flight Management Systems that utilize augmented GPS signals for navigation and positioning purposes were scheduled to be contained by American and United airlines Boeing 757s and 767s by 2000.
"Factors that can degrade the GPS signal and thus affect accuracy include the following: Number of satellites visible - The more satellites a GPS receiver can "see," the better the accuracy; Satellite geometry/shading - This refers to the relative position of the satellites at any given time. Ideal satellite geometry exists when the satellites are located at wide angles relative to each other. Poor geometry results when the satellites are located in a line or in a tight grouping."
Remember the accuracy we are interested in is the GPS flying the airplane
not the unit sending the GPS signal whose accuracy is never les than one half of a mile.
Remember that all computations are in nautical miles and that is why we use 6020 (one nautical mile) instead of 5,280 feet, one statute mile.
I am not sure what this GPS exercise is about because the alleged Arab hijacker could never have programmed a flight and then inserted it into the FMS or flight management system and then hooked it up to the autopilot.
If we are talking about military grade GPS this exercise would be far too risky to attempt even with the most accurate GPS.
And to make my position clear there is no possibility that any of the 4 alleged hijacked airplanes crashed anywhere. Not into the WTC, not into the Pentagon and not into the field at Shanksville.