NAVE

Encoding of television signals such as in the Nielsen system is used for audience measurement; e.g., to accurately identify television distributors (including broadcast stations or cable networks). The Nielsen Media approach installs metering devices at the user’s premises. This device identifies stations and networks tuned into by the end user. By encoding content with a NAVE unit, ratings data for programming can be provided, whether it is received in a digital, analog, or combined viewing environment. Reading the aforementioned watermarks or other codes inserted into the television signal at the distribution source through the NAVE unit captures this end user data.

Figure: NAVE Watermarking

The Nielsen Audio Video Encoder (NAVE) is a system capable of inserting Nielsen Media Research proprietary NAVE source identification watermarking directly into the audio portion of compressed digital ATSC transport streams prior to broadcast. NAVE devices can simultaneously insert watermarking data on multiple independent digital television programs being broadcast whether they are standard definition (SDTV) or high definition (HDTV). The watermark is capable of identifying the Provider Content (PC), the network the content was distributed (NT), and the final distributor (FD), say in the case of local broadcast station or cable channel. The watermarks include a timestamp so if the content is viewed time shifted (VOD) within a reasonable time frame that usage data is also captured.

If any station’s NAVE encoder is interrupted, the meter device installed in Nielsen sample premises collects and stores passive signatures for all non-encoded programming viewed. These signatures are downloaded each night to Nielsen’s operations center. To identify viewing, the passive signatures collected from the meter device in the premises are matched against the signatures in the library.

The feature allows you to define the watermarks to be accepted and the faults/recoveries to occur by configuring the watermark’s creation time and the number of good watermarks that should be received per period.

Figure: Encoder Features - NAVE

Table: NAVE

Enable	Enable/disable Nielsen Audio Video Encoder monitoring. This feature requires a subscription to Nielsen service.
Score Line	Percentage of good watermarks in the monitored window. Note: is been labeled “Error Percent” in early versions of MIP.
Levels	Filters watermarks by their levels.
FD	Final Distributor – entity that delivered content to customer.
PC	Provider Content – entity that originated content.
VOD	Video on Demand – time shifted viewing.
NT	Network that delivered the content.
Minimum good watermarks:	If the number of good watermarks during the sliding window is lower than the minimum value, a fault is detected.
Station IDs:	A list of good watermarks you intend to accept. If the field is left empty, all watermarks will be detected. Some channels support more than one Station ID (SID). In this case, insert into the SID array of all the IDs you intend to accept. A single SID is sufficient to satisfy the Minimum Good Watermarks and Watermark Percentage recovery variables to avoid faults and stay recovered.
Warning percent:	If the value is greater than Score Line but less then Warning Percent, a warning message will be sent. Any other case results in recovery.
Watermark age:	The watermark’s time from its creation.
Watermark max age:	Filters out watermarks older than this threshold and reports no faults on these. If left at 0, variable watermark age is taken. For example, if this watermark is 10 ignored. If the watermark’s age is less than this threshold it will be processed as a regular watermark.
Window interval:	Faults are detected and recoveries enabled during the sliding window interval. For example, if you define a 30 second window, for each second the 30 second window will be checked (0-30, 1-31, 2-32…) against the various parameters used.