[time-nuts] over-determined clock solution

[Steve]

The phrase "over-determined clock solution" is used in the Trimble 
Thunderbolt user manual in describing operation of the Thunderbolt GPS 
receiver. The manual does not discuss the phrase in any detail, 
appearing to assume the reader understands its meaning. An internet 
search on "over-determined clock solution" did not turn up any 
substantive hits.

What does "over-determined clock solution" mean?

Thanks.

Steve, K8JQ