A disk drive is disclosed which generates a pole tip protrusion (PTP) measurement
by performing a write operation to heat the transducer while measuring a fly height
of the transducer. A first data sequence written to the disk is read without heating
the transducer to generate a first signal measurement. A second data sequence is
then written to the disk in order to heat the transducer, and the first data sequence
is again read to generate a second signal measurement. The PTP measurement is then
generated in response to the first and second signal measurements.