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Originally Posted by lek
It means that you are apparently not interested enough of the mission to even check things yourself.
You are asking if ~1min audio clip is real time recording of an event that took ~1.5 hours? :roll:
And all the fuss about the parachutes is just as "accurate".
The proper order of doing things is : Read, Think, Post. You seem to have forgotten the first two.
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...Not when you are trying to put together a scientific interpretation of NASA or ESA release data. They did not include in the posting the Doppler frequency, the angle of the radar relative to the ground, the time signature ect ect ect:
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Originally Posted by ESA
This recording was produced by converting into audible sounds some of the radar echoes received by Huygens during the last few kilometres of its descent onto Titan. As the probe approaches the ground, both the pitch and intensity increase. Scientists will use intensity of the echoes to speculate about the nature of the surface.
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So I am stuck with 'the last few kilometers' and the fact that it is continuous (the acoustic data was spliced together), and includes the termination sequence on landing. Since they were expecting to impact at ~5m/s, a seventy second sequence should correspond to the last ~400 meters, not several kilometers. So I am stuck asking if anyone can confirm it is real time, but even more so, does anyone have a better or different interpretation?
FWIW, I spent more than three hours trying to piece that together, and an hour on the phone with other physicists.
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Originally Posted by Hamlet
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Originally Posted by Jerry
If you happen to have the descent profile for the Spirit and Opportunity missions, I would appreciate those as well, because to the best of my knowledge, NASA has never released them.
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Really?
I posted the Mars Exploration Rovers Entry, Descent, and Landing Trajectory Analysis last week. This document shows the predicted EDL values and the actual values they've been able to reconstruct so far...
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Yes you did, thank you
and I combed through that data last week looking for something, anything that would allow me to estimate the
acceleration of gravity on Mars - and
every one of the parameters that would be useful to this end are missing from the paper! Including all the mach numbers, the heating rate (vr prediction) the peak stagnation pressure, total heat load, altitude at which the heat sheild jetisoned, dynamic pressure, sensed acceleration, and time from entry or parachute deployment to 'bouncedown'
How long does it take to reconstruct the peak pressure and sensed acceleration? How long does it take a rocket scientist to pinpoint the time of landfall? Are they camping on this data because, like the Viking data, they cannot recreate a plausible physical scenario?
(Although the time of landing would be a constraining parameter for estimating the gravity of Mars, for Huygens, the time of landfall is almost meaninless, since the second parachute was a timed, or programmed release after the deployment of the first parachute.)