I have several devices locate in building (just normal commercial buildings). I would like to know in which city they are so is there any suggestion for the gps module? each should be <$100.
Thanks in advance.
Sparkfun used to sell a module which could get an acceptable signal indoors. I don't think you need to spend more than $30 to achieve your goal.
Most people want to get higher accuracy than "city" and a GPS alone can never achieve that accuracy indoors, so nobody bothers to measure indoor performance.
I heard that gps M8N module has very good performance in terms cold start time and signal quality. And it has been used a lot in drones. I wonder if anyone has ever done any test on that.
There are performance tests here;
Although the comment 'normal commercial buildings' is fairly meaningless really, I spent 15 years or so installing networks in 'normal commercial buildings' and they vary a great deal in construction.
I suspect your going to be dissapointed, if it were possible or reliable to track objects indoors with GPSs it would be widly done.
My shed has only very thin concrete walls and a corrugated fibre roof, all very much less solid than a 'normal commercial buildings' some of the GPSs in the review. In the shed some of the GPSs might eventually get a fix, and none of them will ever get a fix in my nearby 'normal domestic building', although some might if they are next to a window.
Rolykine:
I even didn't hear about this one before. How much does it cost?
I think it is call ublox M8N, used a lot in diy drones like f450s. around $20.