You'd be surprised how many GPS devices never cold start. I've worked with multiple serial GPS receivers that stored the last solution in nonvolatile memory as

You'd be surprised how many GPS devices never cold start. I've worked with multiple serial GPS receivers that stored the last solution in nonvolatile memory as a start point. A quick way to check: buy a brand new one, plug it in, and see if it starts offering (low-quality) fixes for Shenzhen or wherever it was QAd. Unfortunately some receivers won't actually provide NMEA sentences until the quality flag goes on, so it's not quite this obvious, but I just recently bought an industrial cellular modem with onboard GPS and experienced a 30 minute or so wait before the quality flag came on and I started getting NMEA sentences. Presumably it was busy discovering it wasn't in Kansas any more.