Okay, okay... maybe we have to “reverse engineer” this stuff, but maybe we don’t.   What does this hardware vendor say about the packets that their equipment is designed to produce?

A quick search for “gps” on http://search.cpan.org certainly points out a lot of material.   (Take no offense at my asking this, but ...) Have you looked at all of this already?   Does any of it apply?

Perl functions such as pack() can make short work of dealing with binary packets like this one ... but of course, there’s no sense in doing anything only to discover that it has already been done.   :-)   And I’m sure that they don’t consider the format to be secret.

(If it comes to that... sure are looking forward to a new CPAN module from you!)