Patent ID: 7684141

Claim:
A computer-implemented method, comprising: calculating an estimate of an interval to degrees translation factor that represents a measurement angle interval divided by a first pulse count, wherein the first pulse count represents magnetic format transitions counted during an angular measurement interval, wherein a servo format is formed by the magnetic format transitions written on a tape medium, wherein the measurement angle interval is determined with a reference angle sensor; and determining a reel motor angle using the estimate by: receiving an indication that a rotating reference point has crossed a stationary reference point, wherein the indication is recognized as indicating that an angle between a motor rotor and a motor stator is a reference angle; determining a second pulse count, wherein the second pulse count represents magnetic format transitions counted since the indication was received to a given point in time; and at the given point in time, multiplying the second pulse count by the estimate to generate a first value; and adding the reference angle to the first value to generate the reel motor angle.