solletica
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According to Immarsat, the comapny was able to pinpoint the plane's last location from the Doppler shift in the wavelength of the pings generated from the plane. . .
Except this makes no sense from physics. The Doppler shift of the wavelength of radio waves is way too small to be detected when the source (i. e. airplane) is moving at speeds much less than c. Doppler shifts are only easily measured for subluminal waves, i. e. sonar.
The satellite would've had to be specifically designed to pick up such small shifts--a very expensive endeavor, and so there would've been no reason to make it do that. Each satellite was designed to transmit data to planes, not determine its altitude, location, etc.
More than one satellite would've had to have picked up the pings for Immarsat to use that data to determine the plane's exact location at the time of the last ping.
A key calculation done by Inmarsat was determining the “Doppler shift” in the ping, or the slight change in the frequency of the signal caused by the movement of the aircraft relative to the satellite in space.
“From that process – a compression or an expansion of the wavelengths – you can determine whether the aircraft is getting closer or farther away,” McLaughlin explains. “It’s been a groundbreaking but traditional mathematics-based process that was then peer-reviewed by others in the space industry, and indeed contributed to by Boeing.”
The data analyzed was generated by pings from MH370 to one of Inmarsat’s 10 satellites. McLaughlin likened the Inmarsat avionics and antenna on an aircraft to a mobile phone, while the applications that use the satcom link, including the Aircraft Communications and Reporting System (ACARS), are “apps.” On MH370, “the apps were turned off, but the handset wasn’t,” he explains.
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Except this makes no sense from physics. The Doppler shift of the wavelength of radio waves is way too small to be detected when the source (i. e. airplane) is moving at speeds much less than c. Doppler shifts are only easily measured for subluminal waves, i. e. sonar.
The satellite would've had to be specifically designed to pick up such small shifts--a very expensive endeavor, and so there would've been no reason to make it do that. Each satellite was designed to transmit data to planes, not determine its altitude, location, etc.
More than one satellite would've had to have picked up the pings for Immarsat to use that data to determine the plane's exact location at the time of the last ping.