Abstract: An audience measurement system meters tuning of a receiver which receives a plurality of program signals transmitted over a plurality of channels. The receiver is located in an audience site within a dwelling, and the plurality of program signals enter the dwelling through a service entrance and are supplied therefrom to the audience site. The audience measurement system includes a code inserter, a decoder, and a home unit. The code inserter inserts a local code in each of the program signals at a location which is intermediate the service entrance and the audience site. This local code includes a unique local code inserter ID and a code inserter time stamp. The decoder decodes the unique local code inserter ID and the code inserter time stamp at the audience site. The home unit is located in the dwelling and collects and stores the decoded unique local code inserter ID and code inserter time stamp.

Abstract: A method and apparatus are provided for determining a particular transmitting station from which program signals are received and translated by a monitored receiver within a test area and including mobile receivers. A stored transmitter characteristic table includes a corresponding transmitting station identification stored with a predefined subarea of a plurality of predefined subareas within the test area for each predetermined tuned frequency of the monitored receiver. A tuned frequency of the monitored receiver is identified and the particular transmitting station corresponding to the identified tuned frequency is identified responsive to both the identified tuned frequency of the monitored receiver and the stored transmitter characteristic table. The identified transmitting station data is stored with time of occurrence data.