Trying to work out which GPS/INS book to spend your $100 on? Maybe Farrell's book? Aided Navigation: GPS with High Rate Sensors Titterton's? Strapdown Inertial Navigation Technology (IEE Radar, Sonar, Navigation and Avionics Series) Or one of the others out there?

Answer: This one. It's clearer and more complete than Farrell and covers more ground than Titterton. It's accessible and readable. You can actually start from the word go and actually implement a complete GPS/INS with this book. Score!

The book, however, is not perfect. It's chapter on augmenting other sensors is superficial and incomplete. It states, but does not go into much detail about the manoeuvre requirements for attitude observability. It's missing direct-form implementations of GPS/INS and with it, several more modern estimation methods (e.g. particle filter, UKF, ...).

However, against the book's peers it's a good step ahead and recommended for both students in the field and practitioners.