Apparatus and method for detecting and correcting a corrupted broadcast time code

A method for identifying and correcting one or more of a plurality of time codes extracted from a broadcast signal, said method comprising the steps of:

• recording a set of read times, each of said read times corresponding to one of said time codes, and each of said read times indicating when said corresponding time code was extracted from said broadcast signal;
• determining a set of first intervals between said read times;
• determining a set of second intervals between said time codes, each of said second intervals corresponding to one of said first intervals;
• comparing each of said first intervals to each corresponding ones of said second intervals to determine whether said first intervals are approximately equal to said corresponding second intervals;
• identifying a subset of said second intervals that are not approximately equal to a corresponding subset of said first intervals based on a result of said comparing, wherein each of said subset of second intervals are associated with at least one corrupted time code;
• and
• calculating a corrected time code for said at least one corrupted time code.

A storage medium for storing software for detecting and correcting one or more of a plurality of time codes extracted from a broadcast signal, the software being computer readable and the software including instructions for causing a computer to:

• receive a set of time codes;
• receive a set of read times, each of said read times corresponding to one of said time codes, and each of said read times indicating when said corresponding time code was extracted from a broadcast signal;
• calculate a set of first intervals between said read times;
• calculate a set of second intervals between said time codes, each of said second intervals corresponding to one of said first intervals;
• compare each of said first intervals to each corresponding second interval to determine whether said first intervals are approximately equal to said corresponding second intervals;
• identify a subset of said second intervals that are not approximately equal to a corresponding subset of said first intervals based on a result of said comparison, wherein each of said subset of said second intervals are associated with at least one corrupted time code;
• and,
• calculate a corrected time code for said at least one corrupted time code.

An apparatus for processing audience measurement data, said apparatus comprising:

• means for receiving a plurality of time codes extracted from a broadcast signal;
• means for recording a plurality of read times, each of said read times corresponding to one of said time codes;
• means for calculating a set of first intervals between said read times, wherein each first interval is calculated by determining a difference between two of said read times;
• means for calculating a set of second intervals between said time codes, wherein each second interval is calculated by determining a difference between two of said time codes, and wherein each of said second intervals corresponds to one of said first intervals;
• means for comparing each of said first intervals to each of said corresponding second intervals to determine whether one or more of said time codes are corrupted.

A method of identifying one or more corrupted time codes, the method comprising steps of:

• receiving a set of time codes extracted from a broadcast signal;
• recording a set of read times, each of said read times corresponding to one of said time codes and each of said read times indicating when said corresponding time code was extracted from said broadcast signal;
• calculating a set of first intervals between said read times;
• calculating a set of second intervals between said time codes, said second intervals corresponding to said first intervals;
• comparing each of said first intervals to corresponding ones of said second intervals to determine whether said first intervals are approximately equal to said corresponding second intervals;
• and,
• identifying one or more of said time codes that are corrupted based on a result of the comparing.

An apparatus for processing audience measurement data, said audience measurement data including a plurality of time codes and a plurality of read times, each of said read times corresponding to one of said time codes, the apparatus comprising:

• an input port for receiving a plurality of data records, each data record comprising one of said time codes and a corresponding one of said read times;
• and
• a processor adapted to determine when said time codes and said corresponding read times are time locked such that a first time code and a first read time included in a first data record have increased by an approximately equal amount relative to a second read time and a second time code included in a second data record, said first data record being received at said input port later than said second data record, wherein said processor is further adapted to determine when said time codes and said corresponding read times are not time locked such that a third time code and a third read time included in a third data record have not increased by an approximately equal amount relative to a fourth read time and a fourth time code included in a fourth data record, said third data record being received at said input port later than said fourth data record, and wherein said processor is further adapted to determine when said time codes and said read time experiences one or more transitions between being time locked and not being time locked and to use said transitions to identify one or more of said time codes that are corrupted, and further wherein said processor is adapted to calculate one or more corrected time codes for said corrupted time codes.

A method of processing audience measurement data, said method comprising the steps of:

• receiving a plurality of time codes;
• generating a plurality of read times, said read times corresponding to said time codes;
• determining whether said time codes and said corresponding read times are time locked;
• identifying one or more corrupted time codes depending on whether said time codes and said corresponding read times are time locked;
• and
• calculating one or more corrected time codes to replace one or more said corrupted time codes.