Fig. 4From: Compositional variations along the route of Chang’e-3 Yutu rover revealed by the lunar penetrating radarThe relationship between the centroid frequency of the received signal (fr) and the time-delay for each segment of the LPR data. The data segments (a–j) are divided according to the adjacent navigation points from N105 to N208. The red lines are the best-fit between fr and τ using the least square method. The slopes of the best-fit lines are the drift rate of fr with τBack to article page