Originally posted by touchdowntrojans
reply to post by ngchunter
Such an important point and there seems to be so much confusion about it, seems worth repeating my point in a slightly different way; NASA claimed that determinining an Apollo ship's state vector was most accurately done from the ground with the tracking dishes. But the dishes have absolutely no way to check the accuracy of the ship's attitude. The astronauts aligned the IMU(at least checked it) with their scanning telescope, sextant and AGC.
No one said the attitude was determined from state vectors uploaded from the ground. That was done by the astronauts, not the ground. The state vectors were uploaded however (and from there updated and maintained using accelerometers), and from this it was a trivial matter for the computer to automatically account for stellar aberration when making a P52 alignment. Patrick (which I assume is you) claimed that the computer did not calculate for stellar aberration. That is a lie. It did.
But this is not at all the same as saying the shaft and trunion angles were determined from the state vector. Such a statement would be and is nonsensical.
No one made such a statement. P52 aligned the spacecraft's attitude. I've done it myself many times in a simulation that ran the actual apollo guidance computer software on emulated hardware in a simulated version of the solar system. It worked for getting the attitude accurate enough to get to the moon and back successfully and accurately.
