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RandallB
RandallB is offline
#6
Feb19-06, 02:07 PM
P: 1,545
Garth
Can you help me understand the Gravity B tests here? I’m having trouble understanding the expected direction of change in angles expected.

First as I read the polar orbit of GPB it is moving north to south as it is viewing IM-Pegasi the guide star being used. (In close alignment with it the guide star would always be blocked by earth during the south to north trip)

First:
GPB gravitomagnetic frame dragging precession.
The most significant measurement to be made (at least some say and IMO). It is the annual change in the orbital alignment with the guide star.
Do I read the term “E-W precession” correctly as relating the alignment moving in the direction of the rotation of earth (as there is no orbital E-W component to precess)? Thus all the theories named here are predicting the orbit to move its alignment to the east of the guide star. Is this correct?

Actually, I would expect the alignment to move west, so I was looking for a theory that agrees with a westward change. I take it then you are not aware of any theory that does.

Second:
GPB Geodetic precession
Looking at the Satellite on the IM-Pegis side of the orbit at the equator. The angle of deflection relates to the alignment of the gyro axis moving. Given three idea gyros at this point in the orbit and axis aligned; 1) E-W, 2) N-S, 3) Earth Radius, which of the three would have their alignment move and which way?
I assume one will not move at all.
Would direction of gyro rotation have any effect on direction?
And do you know a web site that does a good job of explaining why GR expects this beyond just saying “because of GR space-time curvature”.

Thanks
RB