Hello,

I'm having trouble understanding what "dual DME" updating means.
The manual says
Quote:

Then follows a description how to enter a DME for updating.

But there is no explanation on how to enter two separate DMEs for dual DME updating.
Or does dual DME updating just mean that one DME (off track) is used to update INS1 and another (along track) is used to update INS2, using the procedure described on both units independently? If that is the case, is the updating information shared between INS1 and INS2 so both updates improve the accuracy on either INS?

Also, I have a basic question understanding the DME update process itself: If I interpret the manual correctly, you can update the INS using a DME receiver tuned to a VORDME or DME facility. I assume that the only information fed from the DME receiver to the INS is the distance information. A bearing information is not transmitted. That means, the INS then knows that the actual position is on a circle of known radius (DME distance) around the station coordinates. If there is no bearing information transmitted, the INS doesn't know where exactly on the circle it is. I assume the INS calculates the point on the circle that is nearest to the pure INS position?
Or am I mistaken and a bearing information is used for updating?

Regards,
Philipp