The apollo LM panel had a cross pointer that displays the horizontal velocity to the pilot. This ideally have to be made zero during landing for soft touch down by pilot
My question is, how this information is derived? Is it derived by knowledge of state vector in LM converted to local frame velocity. If that is so, then it means it is inertial propagated velocity and thus can be erroneous?
Or did apollo have three axis velocity measurements available from radar?
After some googling I found a link LDG and Altimeter which says that landing radar had three beams to provide three axis velocity.