In-flight INS alignment
Salute!
I am having a problem with GPS-aided inflight alignment of the inertial nav function ( not the basic attitude reference). What's the deal?
As long ago as 1968 - 1969 our jet could use the doppler ( no GPS for many moons) for an airborne alignment and then one nav fix from anyplace to have good nav - think less than a mile for course steering and positional accuracy, velocities, ground speed, etc..
@ BOAC and others....... The GPS can provide true ground track and outstanding positional accuracy (how do you think those new smart bombs hit within 5 meters using GPS?). Vertical might be up to a hundred meters off at first, but big deal. Baro data can be filtered to improve the vertical stuff as time marches on. And way up north, lattitude was a biggie until we got good inertials and then GPS.
I am having trouble understanding why over 40 years later we would have problems doing an in-flight alignment if all the nuggets did was turn off the inertial system(s).
Anybody here ever tried an in-flight alignment?