I can relate to that. The same happens to me, particularly if I am only napping during a night on call.
Basically, when we sleep we go through several cycles (sleep architecture) which vary from deep sleep to REM sleep to non-REM sleep. in some of the more superficial cycles, the transition sometimes is not so "well accomplished", particularly if we are not actually resting (tense sleep, like when you have to wake up soon thereafter). What follows is that your musculature is abnormally relaxed, particularly the pharyngeal muscles, while you are already on the transition to consciousness, hence you can hear yourself snoring.
This is indeed a sign of a non-fullfilling sleep. If it happens only during a nap, no problem. If indeed it happens at night, you might be having some trouble getting adequate sleep. A night on a sleep laboratory might help solve the problem.
For me, I just pass out when I get home... for 20 hours non-stop sometimes!