Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed to determine whether audience measurement meters are co-located. An example apparatus is to, based on a difference between a first sampling time of a first entry of a first log and a second sampling time of a corresponding entry of a second log satisfying a first threshold, determine at least one matching instance of at least one first device identifier of the first entry and at least one second device identifier of the corresponding entry. Additionally, the example apparatus is to populate a variable with the at least one matching instance. The example apparatus is also to, based on a metric satisfying a second threshold, cause transmission of an alert indicating that a first meter and a second meter were co-located during generation of the first log and the second log, the metric based on the at least one matching instance.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed for delivering extended payloads with composite watermarks. Examples disclosed herein embed a first watermark into a media stream in accordance with a first watermark technology, where the first watermark includes a first indicator bit and a first payload. Disclosed examples also embed a second watermark into the media stream in accordance with a second watermark technology, where the second watermark includes a second indicator bit and a second payload. In some disclosed examples, the first indicator bit and the second indicator bit are to indicate whether the first payload and the second payload are to be combined when the first watermark and the second watermark are decoded.

Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed to determine whether audience measurement meters are co-located. An example apparatus is to, based on a difference between a first sampling time of a first entry of a first log and a second sampling time of a corresponding entry of a second log satisfying a first threshold, determine at least one matching instance of at least one first device identifier of the first entry and at least one second device identifier of the corresponding entry. Additionally, the example apparatus is to populate a variable with the at least one matching instance. The example apparatus is also to, based on a metric satisfying a second threshold, cause transmission of an alert indicating that a first meter and a second meter were co-located during generation of the first log and the second log, the metric based on the at least one matching instance.

Abstract: Example apparatus disclosed herein include a watermark detector to detect watermarks in a media signal. Disclosed example apparatus also include a controller to operate the watermark detector to (1) detect a first watermark in the media signal, and (2) cycle between sleep intervals and active intervals based on a repetition rate of the watermarks in the media signal to perform a detection operation for a second watermark at a second location in the media signal relative to a first location of the first watermark in the media signal. In some examples, the controller is to search a buffer of prior detected watermark symbols to detect a third watermark at a third location prior to the second location in the media signal in response to the second watermark not being detected at the second location in the media signal.

Abstract: Methods and apparatus are disclosed for supplementing partially readable and/or inaccurate codes. An example apparatus includes a watermark analyzer to select a first watermark and a second watermark decoded from media; a comparator to compare a first decoded timestamp of the first watermark to a second decoded timestamp of the second watermark; and a timestamp adjuster to adjust the second decoded timestamp based on the first decoded timestamp of the second watermark when at least a threshold number of symbols of the second decoded timestamp match corresponding symbols of the first decoded timestamp.

Abstract: Methods, apparatus, systems and articles of manufacture to extend a timestamp range supported by a watermark without breaking backwards compatibility are disclosed. An example watermark encoder includes a counter to increment symbols of a watermark timestamp and a controller to control the counter to increment the symbols of the watermark timestamp based on a key, the controller to cause the counter to restrict ones of the symbol values to increment over one of a first range of symbol values or a second range of symbol values based on a value of the key, the second range of symbol values different from the first range of symbol values.

Abstract: Example systems, methods, apparatus and articles of manufacture for wirelessly modifying detection characteristics of portable devices are disclosed herein. Example portable devices include example radio circuitry and example processor circuitry. In disclosed examples, the example processor circuitry is to cause the radio circuitry to scan for radio frequency beacons. The example processor circuitry is also to trigger activation of audio monitoring via a microphone of the portable device in response to establishment of a first connection with a first radio frequency beacon, the audio monitoring to at least one of detect an audio code or generate an audio signature. The example processor circuitry is further to cause the audio monitoring to stop in response to establishment of a second connection with a second radio frequency beacon different from the first radio frequency beacon.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed for delivering extended payloads with composite watermarks. Examples disclosed herein embed a first watermark into a media stream in accordance with a first watermark technology, where the first watermark includes a first indicator bit and a first payload. Disclosed examples also embed a second watermark into the media stream in accordance with a second watermark technology, where the second watermark includes a second indicator bit and a second payload. In some disclosed examples, the first indicator bit and the second indicator bit are to indicate whether the first payload and the second payload are to be combined when the first watermark and the second watermark are decoded.

Abstract: Example apparatus disclosed herein include a watermark detector to detect watermarks in a media signal. Disclosed example apparatus also include a controller to operate the watermark detector to (1) detect a first watermark in the media signal, and (2) cycle between sleep intervals and active intervals based on a repetition rate of the watermarks in the media signal to perform a detection operation for a second watermark at a second location in the media signal relative to a first location of the first watermark in the media signal. In some examples, the controller is to search a buffer of prior detected watermark symbols to detect a third watermark at a third location prior to the second location in the media signal in response to the second watermark not being detected at the second location in the media signal.

Abstract: Methods and apparatus are disclosed for supplementing partially readable and/or inaccurate codes. An example apparatus includes a watermark analyzer to select a first watermark and a second watermark decoded from media; a comparator to compare a first decoded timestamp of the first watermark to a second decoded timestamp of the second watermark; and a timestamp adjuster to adjust the second decoded timestamp based on the first decoded timestamp of the second watermark when at least a threshold number of symbols of the second decoded timestamp match corresponding symbols of the first decoded timestamp.

Abstract: Example apparatus to improve timestamp transition resolution of watermarks are disclosed. A disclosed example apparatus is to decode timestamps in respective ones of detected watermarks, estimate a first transition window indicative of a transition between a first time period to a second time period based on a first one of the timestamps and a second one of the timestamps, and when the first transition window does not satisfy a threshold, estimate a second transition window indicative of a transition between the second time period and a third time period based on the second one of the timestamps and a third one of the timestamps. The disclosed example apparatus is also to determine a first mapped transition window based on an intersection of the first transition window and the second transition window, and set the first mapped transition window as a reference time transition window for subsequent time periods.

Abstract: Methods and apparatus are disclosed for supplementing partially readable and/or inaccurate codes. An example apparatus includes a watermark analyzer to select a first watermark and a second watermark decoded from media; a comparator to compare a first decoded timestamp of the first watermark to a second decoded timestamp of the second watermark; and a timestamp adjuster to adjust the second decoded timestamp based on the first decoded timestamp of the second watermark when at least a threshold number of symbols of the second decoded timestamp match corresponding symbols of the first decoded timestamp.

Abstract: Methods, apparatus, systems and articles of manufacture to extend a timestamp range supported by a watermark without breaking backwards compatibility are disclosed. An example watermark encoder includes a counter to increment symbols of a watermark timestamp and a controller to control the counter to increment the symbols of the watermark timestamp based on a key, the controller to cause the counter to restrict ones of the symbol values to increment over one of a first range of symbol values or a second range of symbol values based on a value of the key, the second range of symbol values different from the first range of symbol values.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed for associating different watermarks detected in media. An example method disclosed herein includes determining whether a first watermark detected in a media signal is represented in a watermark data structure and associating the first watermark with a first media presentation record associated with a second watermark in response to the first watermark being associated in the watermark data structure with the second watermark. The example method further includes transmitting monitoring data including the first media presentation record to an audience measurement entity.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed for associating different watermarks detected in media. An example method disclosed herein includes determining whether a first watermark detected in a media signal is represented in a watermark data structure and associating the first watermark with a first media presentation record associated with a second watermark in response to the first watermark being associated in the watermark data structure with the second watermark. The example method further includes transmitting monitoring data including the first media presentation record to an audience measurement entity.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed for delivering extended payloads with composite watermarks. Examples disclosed herein embed a first watermark into a media stream in accordance with a first watermark technology, where the first watermark includes a first indicator bit and a first payload. Disclosed examples also embed a second watermark into the media stream in accordance with a second watermark technology, where the second watermark includes a second indicator bit and a second payload. In some disclosed examples, the first indicator bit and the second indicator bit are to indicate whether the first payload and the second payload are to be combined when the first watermark and the second watermark are decoded.

Abstract: Example systems, methods, apparatus and articles of manufacture for wirelessly modifying detection characteristics of portable devices are disclosed herein. Example portable devices include example radio circuitry and example processor circuitry. In disclosed examples, the example processor circuitry is to cause the radio circuitry to scan for radio frequency beacons. The example processor circuitry is also to trigger activation of audio monitoring via a microphone of the portable device in response to establishment of a first connection with a first radio frequency beacon, the audio monitoring to at least one of detect an audio code or generate an audio signature. The example processor circuitry is further to cause the audio monitoring to stop in response to establishment of a second connection with a second radio frequency beacon different from the first radio frequency beacon.

Abstract: Methods and apparatus are disclosed for supplementing partially readable and/or inaccurate codes. An example apparatus includes a watermark analyzer to select a first watermark and a second watermark decoded from media; a comparator to compare a first decoded timestamp of the first watermark to a second decoded timestamp of the second watermark; and a timestamp adjuster to adjust the second decoded timestamp based on the first decoded timestamp of the second watermark when at least a threshold number of symbols of the second decoded timestamp match corresponding symbols of the first decoded timestamp.

Abstract: Example apparatus to improve timestamp transition resolution of watermarks are disclosed. A disclosed example apparatus is to decode timestamps in respective ones of detected watermarks, estimate a first transition window indicative of a transition between a first time period to a second time period based on a first one of the timestamps and a second one of the timestamps, and when the first transition window does not satisfy a threshold, estimate a second transition window indicative of a transition between the second time period and a third time period based on the second one of the timestamps and a third one of the timestamps. The disclosed example apparatus is also to determine a first mapped transition window based on an intersection of the first transition window and the second transition window, and set the first mapped transition window as a reference time transition window for subsequent time periods.

Abstract: Systems, methods, apparatus, and articles of manufacture to improve timestamp transition resolution of watermarks are disclosed.