Nielsen is taking a big step today to close one of its biggest TV ratings measurement gaps: its inability to accurately account for out-of-home viewing in public places like sports bars, gyms and hotels.

In April, the company is launching a new national television out-of-home measurement service using its portable people meter, or PPM, technology and panelists. Clients who subscribe to Nielsen's new service will receive ratings estimates (including C3 and C7) that combine in-home viewing—which is based on the company's national TV ratings panel—with this out-of-home viewing using its PPM panels.

Nielsen said the service—which will provide ratings for live through live-plus-7 days of viewing—will launch in April, and contain data going back to January 2017. Shortly after launch, it will add data that stretches back to September.

The new offering will launch as a stand-alone service, but Nielsen plans to eventually add the out-of-home data to its national ratings.

The PPM device, which panelists carry with them, will allow Nielsen to measure television viewing in places like restaurants, bars, airports and waiting rooms. Nielsen will rely on data from more than 75,000 PPM panelists located in 44 local markets, which the company can use to project out-of-home viewing in more than half of the U.S. population.

"Measuring where consumers watch content, regardless of platform and location, is at the core of Nielsen Total Audience, and this includes out-of-home viewing," said Sara Erichson, evp, client solutions and audience insights for Nielsen. "While consumers have always watched TV outside the home, that viewing has not been measured. This new measurement enables both buyers and sellers to understand the incremental reach of advertising messages."

The measurement will be a boon to news and sports networks like CNN and ESPN, which have a large out-of-home audience that has never been properly measured, so it's no surprise both companies are on board with Nielsen's new service.

"We know that ESPN is viewed virtually anywhere there is a screen–from sports bars to gyms, hotels and the workplace," said Artie Bulgrin, svp of global research and analytics for ESPN, in a statement. "While C3, C7 and beyond are useful to measuring catch-up viewing in the home, this new service gives us the ability to capture out-of-home viewing precisely as it happens, and helps us double down on the power and delivery of live sports, while transacting on new, valuable audience segments for advertisers."

Added Howard Shimmel, chief research officer at Turner, "For brands like CNN and Turner Sports with huge and valuable out-of-home audiences, we need to be able to measure consumption regardless of the platform, screen or location. In collaboration with Nielsen, we were first to market using PPM technology for custom out-of-home solutions for CNN. Nielsen's new National TV Out-of-Home Measurement Service will help us drive these capabilities forward."

Nielsen has been announcing several ratings overhauls as the company works to complete its total audience measurement rollout by March. It will finally stop using paper TV diaries, which are relied upon in 140 local markets, in 2018, and last month launched its digital content ratings metric.