GPS dBic Difference

We were using this GPS unit (ACTPAT184-01-IP) but it is no longer being manufactured. It suggests we instead use this GPS unit (ACTPAT182-01-IP). It looks like the only difference, besides the height (which I don’t care about), is the gain. The old unit has a gain of 2.5dBic and the new one has a gain of 1dBic. I am not familiar with the units of dBic. After googling, I’m still not sure the difference between 2.5dBic and 1dBic. Can you tell me the difference? How will this impact performance? Thank you.

I understand dBiC to refer to antenna gain relative to a (hypothetical) isotropic circularly polarized antenna. Antennas with higher gain generally are more sensitive over a narrower range of physical physical orientation than those with lower gain.

How exactly that might translate into an observable difference in behavior/performance isn’t the most straightforward question in the world, as it’s but one of many factors that play a role. I’d suggest giving the alternative unit an audition, and if it works, run with it.