System and method for analyzing magnetic media surfaces for thermal erasures and other characteristics

1. A magnetic media drive for analyzing magnetic media surfaces for thermal erasures and other characteristics comprising:

a drive channel module configured to measure gain control values for a magnetic media surface, the magnetic media surface having multiple positions where each position includes a servo wedge on which servo samples including a preamble signal is recorded on servo tracks of the magnetic media surface, the gain control values represent the amount of gain applied by the drive channel module to the preamble signal to acquire a desired amplitude;

an acquisition module in communication with the drive channel module, the acquisition module configured to receive a request for measurement of gain control values for a magnetic media surface according to one or more measurement parameters indicating the scope of the measurement and acquiring the gain control values according to the measurement parameters;

a configuration module configured to arrange the acquired gain control values in accordance with their proximity to each other and to organize the gain control values to generate one or more images that represent changes in the characteristics of the magnetic media surface;

an analysis module configured to analyze the one or more images to detect patterns in the one or more images that represent a change in the characteristic of the magnetic media surface and to analyze the patterns to determine measurement values that coincide with the change in the characteristic of the magnetic media surface.

2. The magnetic media module of claim 1 , wherein the measurement values are utilized to determine the root cause of the change in the characteristics of the magnetic media surface.

3. The magnetic media drive of claim 1 , further comprising a filter module configured to filter the image generated to enhance subtle differences in the automatic gain control values that are used to generate the one or more image.

4. The magnetic media drive of claim 1 , wherein the one or more measurement parameters including a geographic location on the magnetic media surface for which the measurement is required.

5. The magnetic media drive of claim 4 , further comprising a comparative module configured to compare a current image of the one or more images with a prior image representing the same geographic location on the magnetic media surface as the current image to identify a change in the pattern of the current image with respect to that of the prior image.

6. The magnetic media drive of claim 5 , wherein the comparative module is further configured to subtract the change in the pattern of a first image from the change in pattern of a second image to determine an incremental change in the image pattern, the first and second images acquired at different moments in time and both representing an image based on the automatic gain control values of a similar geographic location on the magnetic media surface.

7. The magnetic media drive of claim 6 , wherein the incremental change represents a metric to track changes on the magnetic media surface.

8. The magnetic media module of claim 1 , wherein the analysis module is further configured to analyze the one or more images to identify a change in the pattern of a current image with respect to that of one of a threshold image and a prior image, the current image, prior image and the threshold image representing the same geographic location.

9. The magnetic media module of claim 8 , wherein the current image is generated periodically to determine a rate of change in the characteristics of the current image.

10. The magnetic media module of claim 8 , wherein the analysis module is further configured to analyze the current image to detect a pattern in the current image that reveals information related to one of the head velocity and position of the head that corresponds to an occurrence of a change in the pattern of the current image with respect to one of the threshold image and the prior image.

11. The magnetic media module of claim 8 , wherein the analysis module is further configured to analyze the one or more images to determine when a change in the characteristics of the current image with respect to one of a prior image and a threshold image has occurred.

12. The magnetic media drive of claim 1 , wherein the measurement parameter includes a step size.

13. The magnetic media drive of claim 1 , wherein the geographic location is defined by at least a portion of the multiple positions of the magnetic media surface.

14. The magnetic media drive of claim 1 , wherein the geographic location is defined by a radius and a rotational angle on the magnetic media surface.

15. The magnetic media drive of claim 1 , wherein the acquisition module is further configured to sum multiple samples of each servo wedge in each position requested.

16. A method for analyzing magnetic media surfaces for thermal erasures and other characteristics comprising:

measuring gain control values for a magnetic media surface, the magnetic media surface having multiple positions where each position includes a servo wedge on which servo samples including a preamble signal is recorded on servo tracks of the magnetic media surface, the gain control values represent the amount of gain applied by a drive channel module to the preamble signal to acquire a desired amplitude;

receiving a request for measurement of gain control values for a magnetic media surface according to one or more measurement parameters indicating the scope of the measurement and acquiring the gain control values according to the measurement parameters, the one or more measurement parameters including a geographic location on the magnetic media surface for which the measurement is required;

arranging the acquired gain control values in accordance with their proximity to each other and organizing the gain control values to generate one or more images that represent changes in the characteristics of the magnetic media surface;

analyzing the one or more images to detect patterns in the one or more images that represent at least a change in a characteristic of the magnetic media surface;

analyzing the patterns to determine one or more measurement values that coincide with the change in the characteristic of the magnetic media surface, the one more measurement values utilized for detecting the root cause of the change in the characteristic of the magnetic media surface; and

performing a responsive action including generating an error condition when the change in the characteristics of the magnetic media surface exceeds a threshold.

17. The method of claim 16 , further comprising reporting the results of the measurement to a host device.

18. The method of claim 16 , further comprising filtering the image generated to enhance subtle differences in the gain control values that are used to generate the one or more image.

19. The method of claim 16 , further comprising comparing a current image of the one or more images with a prior image representing the same geographic location on the magnetic media surface as the current image to identify a change in the pattern of the current image with respect to that of the prior image.

20. The method of claim 19 , further comprising subtracting the change in the pattern of a first image from the change in pattern of a second image to determine an incremental change in the image pattern, the first and second image acquired at different moments in time and representing an image based on the gain control values of a similar geographic location on the magnetic media surface.

21. The method of claim 20 , wherein the geographic location is specified by a begin position and an end position.

22. The method of claim 16 , further comprising analyzing the one or more images to identify a change in the pattern of a current image with respect to that of a threshold image, the current image and the threshold image representing the same geographic location.

23. The method of claim 22 , further comprising analyzing the current image to detect a pattern in the current image that reveals measurement values related to one of a head velocity and position of the head that corresponds to an occurrence of a change in the pattern of the current image with respect to one of the threshold image and the prior image.

24. The method of claim 16 , further comprising analyzing the one or more images to determine when a change in the characteristics of the current image with respect to one of a prior image and a threshold image has occurred.

25. A system for analyzing magnetic media surfaces for thermal erasures and other characteristics comprising:

means for measuring gain control values for a magnetic media surface, the magnetic media surface having multiple positions where each position includes a servo wedge on which servo samples including a preamble signal is recorded on servo tracks of the magnetic media surface, the gain control values represent the amount of gain applied by a drive channel module to the preamble signal to acquire a desired amplitude;

means for receiving a request for measurement of gain control values for a magnetic media surface according to one or more measurement parameters indicating the scope of the measurement and acquiring the gain control values according to the measurement parameters, the one or more measurement parameters including a geographic location on the magnetic media surface for which the measurement is required;

means for arranging the acquired gain control values in accordance with their proximity to each other and organizing the gain control values to generate one or more images that represent changes in the characteristics of the magnetic media surface;

means for analyzing the one or more images to detect patterns in the one or more images that represent at least a change in a characteristic of the magnetic media surface;

means for analyzing the patterns to determine a measurement values that coincide with the change in the characteristic of the magnetic media surface, the measurement values utilized for detecting the root cause of the change in the characteristic of the magnetic media surface; and

means for performing a responsive action including generating an error condition when the change in the characteristics of the magnetic media surface exceeds a threshold.

26. The system for analyzing magnetic media surfaces of claim 25 , further comprising a means for receiving the request from a host device to measure the gain control values of the magnetic media surface.

27. The system for analyzing magnetic media surfaces of claim 25 , further comprising a means for reporting the results of the measurement to the host device.

28. The system for analyzing magnetic media surfaces of claim 25 , further comprising a means for filtering the image generated to enhance subtle differences in the gain control values that are used to generate the one or more image.

29. The system for analyzing magnetic media surfaces of claim 25 , further comprising a means for comparing a current image of the one or more images with a prior image representing the same geographic location on the magnetic media surface as the current image to identify a change in the pattern of the current image with respect to that of the prior image.

30. The system for analyzing magnetic media surfaces of claim 29 , further comprising a means for subtracting the change in the pattern of a first image from the change in pattern of a second image to determine an incremental change in the image pattern, the first and second image acquired at different moments in time and representing an image based on the gain control values of a similar geographic location on the magnetic media surface.

31. The system for analyzing magnetic media surfaces of claim 25 , further comprising a means for analyzing the one or more images to identify a change in the pattern of a current image with respect to that of a threshold image, the current image and the threshold image representing the same geographic location.

32. The system for analyzing magnetic media surfaces of claim 25 , further comprising a means for analyzing the current image to detect a pattern in the current image that reveals information related to one of the head velocity and position of the head that corresponds to an occurrence of a change in the pattern of the current image with respect to one of the threshold image and the prior image.

33. The system for analyzing magnetic media surfaces of claim 25 , further comprising a means for analyzing the one or more images to determine when a change in the characteristics of the current image with respect to one of a prior image and a threshold image has occurred.