In this study, we conducted long-distance radio propagation experiments at 1mW/145 MHz to realize low-power long-distance communication for wildlife research and disaster prevention telemetry [1]. We successfully realized long-distance communications from a weather balloon (elevation: ~14,000 m) with 1 mW radio power. Furthermore, we demonstrated that our method can achieve such long-distance communication at 10 BPS/1mW with battery cell operation in the SSB mode and that the SNR in the SSB bandwidth is better than -10 dB.

We conducted long distance radio propagation experiments at 1-10mW/145MHz, to realize a low-power long-distance communication for wildlife research and disaster prevention telemetry. In this paper, we describe that we succeeded in long distance communications, from a ferryboat to the top of Mt. Asugiyama (elevation: 501m, distance: 15km) in Kure, Hiroshima, Japan, in the verification test of our method using 3W radio power. We found out that our method has sufficient capability to achieve such a long distance communication at 10BPS/10mW in battery cell operation on a marine, if we use SSB mode and the SNR in SSB bandwidth is better than -10dB.

In this paper, we describe the construction of a long distance communication sensor network node for Arduino. We develop a Mad-SS Shield prototype system, which succeeds in about 5-km transmission with a 1 mW output.