For transmitting data on an energy harvesting budget there is stuff like LoRa, but Image is out of the question here because of the size. Much more likely is t

For transmitting data on an energy harvesting budget there is stuff like LoRa, but Image is out of the question here because of the size. Much more likely is that such devices will be used for tracking, in situations where GPS is using to much power. Especially, as the calculations for that are done at the receivers instead of the transmitter.