Spiral slope approximation of spiral patterns written to a disk of a disk drive

A disk drive that approximates spiral slope in spiral patterns, the disk drive comprising:

• a disk having at least one spiral pattern that extends radially across the disk;
• a head to read a portion of the at least one spiral pattern;
• and
• a processor to approximate a spiral slope of the portion of the at least one spiral pattern by implementing operations including:
• reading amplitude values for the portion of the at least one spiral pattern;
• determining an amplitude value distribution based on the amplitude values;
• determining a curve-fitted function for the amplitude value distribution;
• and
• determining an approximate spiral slope based on the curve-fitted function.

A disk drive that approximates spiral slope in spiral patterns, the disk drive comprising:

• a disk having at least one spiral pattern that extends radially across the disk;
• means for reading a portion of the at least one spiral pattern;
• means for reading amplitude values for the portion of the at least one spiral pattern;
• means for determining an amplitude value distribution based on the amplitude values;
• means for determining a curve-fitted function for the amplitude value distribution;
• and
• means for determining an approximate spiral slope based on the curve-fitted function.