Abstract: Noise in a same-gap, frequency-based servo tape system is reduced by applying correlated noise factors, generated during calibration, to filtered data write signals. The resulting noise values are subtracted from filtered servo signals, at frequencies F1 and F2, to generate first and second noise-compensated servo signals at frequencies F1 and F2. In one embodiment, the F1 and F2 data signals are filtered through two SOBP filters which output the magnitudes of the signals. The F1 and F2 servo signals are similarly filtered. In another embodiment, the F1 and F2 data signals are filtered through two Goertzel filters which output the real and imaginary components of the signals and the F1 and F2 servo signals are similarly filtered through two other Goertzel filters. Correlated noise factors are applied to the outputs of the write data Goertzel filters and the results subtracted from the corresponding outputs of the servo Goertzel filters.

Abstract: A method and apparatus to calibrate a servo sensor disposed on a tape head located adjacent a moving magnetic tape is disclosed where that magnetic tape includes at least one servo edge comprising an interface between a first recorded signal and a second recorded signal, and where the servo sensor provides a servo signal, and where an independent position sensor provides an IPS signal. The method first samples the servo signal and the IPS signal, calculates a transfer function, and forms a first calibration curve. The method then forms an average residual error value. If that average residual error exceeds the maximum allowable residual error, then the method applies an offset to the first calibration curve to form a second calibration curve. That second calibration curve is saved for subsequent use during, for example, read/write/erase operations.

Abstract: A method to calibrate a transducer, whereby the transducer provides a first signal, and whereby a reference provides a reference signal. The first signal is sampled at a sampling rate comprising a reference frequency, and a digital measured first signal waveform is formed. The reference signal is sampled at the sampling rate, and a digital measured reference signal waveform is formed. The real and imaginary components of the measured first signal waveform are determined at (P) harmonics of the reference frequency. A filtered first signal waveform is formed using those real and imaginary components. The real and imaginary components of the measured reference signal waveform are determined at (P) harmonics of the reference frequency. A filtered reference signal waveform is formed using those real and imaginary components. A transfer function is formed using the filtered first signal waveform and the filtered reference signal waveform. A calibration curve is formed using that transfer function.

Abstract: A method to calibrate a servo sensor disposed on a magnetic tape head disposed adjacent a magnetic tape, where that magnetic tape includes at least one servo edge comprising an interface between a first recorded signal and a second recorded signal, whereby the servo sensor is capable of detecting that first recorded signal and that second recorded signal, and whereby an independent position sensor provides an IPS signal comprising the position of the tape head with respect to the tape path. Applicants' method determines and uses initial servo signal information and initial IPS signal information to determine an initial transfer function. That initial transfer function is used to determine a positioning signal where the tape head is alternatingly moved in a first direction and an opposing second direction along a first axis as the tape moves along a tape path such that the position of the magnetic head along the first axis as a function of time comprises a periodic function having the positioning signal.

Abstract: A method to calibrate a servo sensor disposed on a magnetic tape head disposed adjacent a magnetic tape moving along a tape path. The method measures a maximum and a minimum servo signal ratio, establishes target maximum and minimum servo signal ratios, and determines if the measured servo signal ratios include the target ratios. If the measured servo signal ratios include the target servo signal ratios, then the method forms a filtered servo signal waveform using the measured servo signal waveform. The method then uses the filtered servo signal waveform to calculate a transfer function which is saved for subsequent track following.

Abstract: An apparatus and method to read and/or write information from and/or to a moving magnetic tape comprising one or more servo edges using a tape head comprising (N) servo sensors. Bach servo edge comprises an interface between a first recorded signal and a second recorded signal, where each of the (N) servo sensors detects that first recorded signal and that second recorded signal. The method calculates (N) target PES signals and provides (N) measured PES signals. Using the target and the measured PES signals, the method forms (N) weighted PES signals and averages those (N) weighted PES signals to form a Composite PES signal. That Composite PES signal is used to position the tape head.

Abstract: Applicants' invention includes a method and apparatus to calibrate a servo sensor disposed on a tape head located adjacent a moving magnetic tape, where that magnetic tape includes at least one servo edge comprising an interface between a first recorded signal and a second recorded signal, and where the servo sensor detects that first recorded signal and that second recorded signal and provides a servo signal, and where an independent position sensor provides an IPS signal. Applicants' method first samples the servo signal and the IPS signal, and abstracts (N) datapoints from that sampled data. Applicants' method then calculates a transfer function using those (N) datapoints, and forms a first calibration curve. Applicants' method further includes setting a maximum allowable residual error for said first calibration curve. Applicants' method then determines (N) residual error values, each those (N) residual error values corresponding to a measured datapoint/calculated datapoint pair.

Abstract: A method to calibrate a servo sensor disposed on a magnetic tape head disposed adjacent a magnetic tape moving along a tape path. Applicants' method includes providing a positioning signal, where the positioning signal comprises a positioning signal frequency, an amplitude, and a DC offset. Applicants' method moves said tape head alternatingly in a first direction and an opposing second direction along a first axis as the tape moves along a second axis, where the first axis and the second axis are substantially orthogonal, and such that the position of the magnetic head along the first axis as a function of time is determined by the positioning signal.

Abstract: A method to calibrate a servo sensor disposed on a magnetic tape head disposed adjacent a magnetic tape, where that magnetic tape includes at least one servo edge comprising an interface between a first recorded signal and a second recorded signal, whereby the servo sensor is capable of detecting that first recorded signal and that second recorded signal, and whereby an independent position sensor provides an IPS signal comprising the position of the tape head with respect to the tape path. Applicants' method determines and uses initial servo signal information and initial IPS signal information to determine an initial transfer function. That initial transfer function is used to determine a positioning signal where the tape head is alternatingly moved in a first direction and an opposing second direction along a first axis as the tape moves along a tape path such that the position of the magnetic head along the first axis as a function of time comprises a periodic function having the positioning signal.

Abstract: Applicants' invention includes an apparatus and method to read and/or write information from and/or to a moving magnetic tape using a tape head disposed adjacent that magnetic tape, where that tape head includes (N) servo sensors and where that magnetic tape includes (N) servo edges. Each such servo edge comprises an interface between a first recorded signal and a second recorded signal, where each of the (N) servo sensors detects that first recorded signal and that second recorded signal. Applicants' method first calculates (N) target PES signals, where the (i)th target PES signal is determined for the (i)th servo sensor. Applicants method then provides (N) measured PES signals during a read/write operation, where the (i)th servo sensor provides the (i)th measured PES signal. Applicants' method then determines deviation Di, where Di comprises the absolute magnitude of the difference between the (i)th measured PES signal and the (i)th target PES signal.

Abstract: A method to calibrate a transducer, whereby the transducer provides a first signal, and whereby a reference provides a reference signal. The first signal is sampled at a sampling rate comprising a reference frequency, and a digital measured first signal waveform is formed. The reference signal is sampled at the sampling rate, and a digital measured reference signal waveform is formed. The real and imaginary components of the measured first signal waveform are determined at (P) harmonics of the reference frequency. A filtered first signal waveform is formed using those real and imaginary components. The real and imaginary components of the measured reference signal waveform are determined at (P) harmonics of the reference frequency. A filtered reference signal waveform is formed using those real and imaginary components. A transfer function is formed using the filtered first signal waveform and the filtered reference signal waveform. A calibration curve is formed using that transfer function.