The pol argument in lamb.

This selects a sign convention. In addition, if pol=0 (Test Mode), then the 1/R amplitude decay is also removed (as was the case in computing Figure 52). If pol=-1, then an upward motion produces a negative value (the SEG sign convention). Setting pol=+1 reverses the sign convention (upward motion produces a positive number). Interpreting pol for horizontal motion is much more confusing. In real life, one must keep track of the direction to the source, and the relative orientation of a geophone element, and how it is wired. Basically, if pol=0 or pol=+1, then the sign convention of the motion is as shown in Figure 52. If pol=-1, then it is the reverse of what is shown in Figure 52. In that figure, the word “away” means motion away from the source location (in the direction of increasing distance away from the source).