Salute!
Thanks for a better/shorter explanation about the FOG's,
Golden.
And from
Wiede,
And for planes that typically don't have IRS, 12nmi / hour drift rate doesn't seem that bad.
I think Amelia Earhart would take issue with that.
But seriously, Wiede, it sure looks like a very good AHRS system with tiny angular errors and such. The lack of moving parts other than photons and maybe "tuning fork" rate/gee sensors increases reliability as well as size/weight/etc. The "dedicated" inertial nav systems today are an order of magnitude more accurate than what I flew 30 years ago, even without GPS aiding. And they are actually cheaper when considering inflation and such, kinda like the flat-screen HDTV sets at Best Buy.
Gums sends...