The "GPS" standard for aviation navigation is the WAAS or wide area augmentation system. In this system, only two-dimensional positions are derived from the GPS signals -- latitude and lognitude based on the WGS-84 datum. All altitude is derived from the barometric altimeter. There is no provision for GPS derived elevation or altitude. This is not likely to change any time in the future. I was closely involved in the development of the ground and aircraft interface of the WAAS the last few years I worked.
M. F. Moon ------ Original Message ------ Received: Wed, 21 Nov 2007 07:14:31 AM PST From: "Michael Payne" <[EMAIL PROTECTED]> To: "U.S. Metric Association" <[email protected]>Cc: <[EMAIL PROTECTED]>, "Gordon, Trey" <[EMAIL PROTECTED]> Subject: [USMA:39737] Re: altimetry at Boeing There is no Aviation standard of Statute Miles, it's entirely a US standard for visibility, everyone else uses meters, the ICAO standard is meters. This guy might be an engineer at Boeing but he's obviously not knowledgeable about international standards. Russia, Mongolia and China use meters for Altitude, everyone else uses feet or Flight Levels. Mike Payne ----- Original Message ----- >> >> the aviation industry standard for distance is nautical miles, statue >> miles, and feet (altitude). >> meter is never used (even internationally). >> >> Trey Gordon, Ph. D. >> NDE Engineer >> Boeing Phantom Works, Seattle, WA >> [....] >> >> -----Original Message----- >> From: Bossi, Richard H >> Sent: Monday, November 19, 2007 2:55 PM >> To: Gordon, Trey >> Subject: FW: [USMA:39729] Altimeters >> >> Trey, >> >> Would you happen to know the answers to the questions below? >> >> Thanks, >> >> Dick >> >> -----Original Message----- >> From: Patrick Moore [mailto:[EMAIL PROTECTED] >> Sent: Monday, November 19, 2007 12:01 PM >> To: Bossi, Richard H >> Subject: FW: [USMA:39729] Altimeters >> >> I pass along two questions on altimetry posed by one of our metric >> reviewers. Please feel free to delete this message without response to >> me. >> >> But maybe you know a designer at Boeing who could answer easily? >> >> ------ Forwarded Message >> From: <[EMAIL PROTECTED]> >> Reply-To: <[EMAIL PROTECTED]> >> Date: Mon, 19 Nov 2007 13:10:48 -0600 (CST) >> To: "U.S. Metric Association" <[email protected]> >> Subject: [USMA:39729] Altimeters >> >> Michael, >> >> Are altimeters in most aircraft (designed since year ????) now based >> on GPS data rather than on variable atmospheric pressure? >> >> And, are most of the newer GPS altimeters switchable (km and other >> than km)? >> >> Gene Mechtly. >> >> >> ------ End of Forwarded Message >> > > ------ End of Forwarded Message >
