Regarding tracking, I work for rural electric utilities, and we're looking at LoRaWAN for tracking. $30 chip, 15+ mile range in rural environments. Plus it's low power (can run for a year on a battery), and it should meet your low radiation requirement since it doesn't transmit often. Just food for thought.
I don't think anyone has used the LoRa radio signals for triangulating position, but GPS chips are getting really cheap now too. I've been playing around with a $40 GPS module[1] that claims a pretty standard 3 meter accuracy.
