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Cross-Pointer

Adapted by Gary Neff from the LM Apollo Operations Handbook, Vol. 1.

 

 

LM Panel 1

The cross-pointer is located at eye level on LM Panel 1,
just to the right of the Commander's window.
(Click on the image for a larger version.)

 

 

Cross-Pointer

LM cross-pointer schematic in the context of the Abort Guidance System.
(Click on the image for a larger version.)

 

 

The X-Pointer indicator displays forward and lateral velocities, lateral velocities only, or rendezvous radar line-of-sight elevation and azimuth angular rates, depending on the setting of the RATE/ERR MON switch and the MODE SEL switch. Forward and lateral velocities are coincident with the LM Z and Y body axis velocities when the PGNS drives the display. When the landing radar drives the display, forward and lateral velocities are coincident with LM Z and Y axis, from high gate to touchdown. When the AGS drives the display, lateral Y axis velocity only is displayed. When RR is selected, LOS rates are displayed. The red X-pointer power-failure indicator illuminates when power to the X-pointer is interrupted. The X-POINTER SCALE SWITCH controls the scale of X-POINTER indicator:

HI MULT

When LOS azimuth and elevation rates are displayed, this position provides a scale of + -20 mrad/sec. When horizontal velocities are displayed, this position illuminates the X10 multiplier to provide range of + -200 fps.

LO MULT

When LOS azimuth and elevation rates are displayed, this position illuminates the X.1 multiplier to provide a range of + -2 mrad/sec. When horizontal velocities are displayed, this position provides a range of + -20 fps.

 

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