The Half Relocation check box in the LeapFrog / Relocation dialog box (Insert | Alignment | Leapfrog) lets you determine whether or not PC-DMIS performs a FULL RELOCATION (FULL LEAPFROG) operation (if not selected) or performs a PARTIAL RELOCATION (PARTIAL LEAPFROG) operation (if selected).
Relocation refers to moving the portable measuring machine to a new location.
Doing a full relocation (clearing this check box) means you would need to measure something before you move the portable machine and then re-measure some or all of those items after moving the machine. Remeasuring allows PC-DMIS to determine the new location of the machine.
A half relocation (selecting this check box) means you move the portable machine first and then measure the datum features.