Figure 11
From: Development of a Testbed for Wireless Underground Sensor Networks
WUSN testbed results with commodity WSN sensor nodes. RSS versus horizontal internode distance 
.Underground-to-underground (UG2UG) experiment [4]. Burial depths of the sender and the receiver: 
= 40 cm.Underground-to-aboveground (UG2AG) experiment. Burial depth of the sender: 
= 40 cm. Receiver's height: 
= 
.Aboveground-to-underground (AG2UG) experiment. Burial depth of the receiver: 
= 40 cm. Sender's height: 
= 
.