NFL Deep Dive: How 32 Cameras at Each Stadium Drive Virtual Measurement, Boundary Replays, and Skeletal Tracking

Mix of 4K and 8K cameras, along with its Hawk-Eye technology, drive officiating, analysis, and broadcast

From the continued evolution of the leagues’ Next Gen Stats platform to the recently revamped coach’s comms system, the NFL is always on the lookout for new ways to enhance how the game is played, officiated, presented to fans. Chief among those innovations was the installation of a 32-camera array at every NFL stadium prior to this season that has opened up an entire new world of opportunities for the league.

Hawk-Eye 8K cameras were deployed at all 30 NFL stadiums prior to this season.

This Arsenal of ZCam E2-M4 4K cameras and ZCam E2-F8 8K cameras at each venue has enabled in-game virtual measurement for line-to-gain calls, sharper replay looks for close boundary plays, and the testing of a skeletal tracking system for future seasons. This season’s launch marks the culmination of a multi-year, league-wide efforts that required intensive collaboration between the NFL’s Football Innovation, Football Technology, Analytics, and Officiating departments, as well as Sony and its Hawkeye Innovations team.

“The cross-organizational effort behind this has been nothing short of herculean,” says,” Andre Perez, VP, Football Business Strategy & Innovation, NFL. “The nature of our work demands a united effort—not just internally, but also in close collaboration with our partners—to develop, install, and manage a complex tech stack while simultaneously creating new and future use cases that truly support officiating in helpful and unobtrusive ways.”

“Adding to the challenge,” he continues, “these developments often require multiple layers of proposals, policy updates, and committee or ownership approvals, all of which take years of planning to bring to life. Words can’t fully express the gratitude and pride I feel.”

Years in the Making: From Proof of Concept to Reality

With an eye on eliminating the old-school chain gangs on the field, the installation process began with proof-of-concept testing of the 8K Virtual Measurement system throughout the 2023 season at MetLife Stadium. This evolved to include testing of the 4K Boundary/Replay Cameras throughout the 2023 playoffs and at Super Bowl LVIII in Las Vegas.

Following this, the NFL Competition Committee supported the install of the 18-camera system: six 8K cameras for Virtual Measurement and 12 4K cameras for replay along boundary lines (goal line, end line and sideline) ahead of the 2024 season.

The Virtual Measurement system was then tested throughout the 2024 season by NFL Officiating in order to optimize the operational process and calibrate software in advance of the 2025 season. Boundary cameras were used starting in 2024 for replay reviews and after positive feedback, continue to aid NFL officials in the replay process.

The latest installation has been the addition of 14 4K cameras in order to complete the 32-camera array for Skeletal Tracking, which is being tested in the background this season. As of now, the SkeleTrack system cameras are not made available to teams or officials; rather they are being used to evaluate the potential of Sony’s Hawk-Eye’s skeletal tracking system for future seasons.

How It Works: Connecting the Stadium With GameDay Central in NYC

Video is all ingested locally at the stadiums into Sony Hawk-Eye’s array of on-site capture servers. From there, Viewer Client stations both in the stadium and at the Art McNally GameDay Central replay review center in New York City pull the video over network using UDP (User Datagram Protocol). Sony Hawk-Eye subsamples all video feeds to allow for lower bandwidth usage when scanning video.

Upon selection of a given feed, the software instantly provides the viewer full resolution of that given feed for manipulation. Back in New York, this is all done over a 10Gbps pipe from which, about 1-2 Gb is allotted for replay. Additionally, to lessen both storage and bandwidth on the Virtual Measurement cameras, they are programmed to only shoot at 10fps.

“The software requires sharp still images of the ball to perform the measurements,” says Perez, “so higher frames per second aren’t necessary for these cameras.”

Although all tracking data is processed and stored in the cloud, the raw video for all cameras is stored on SSDs on the Sony Hawk-Eye servers for a period of one game. Upon the next home game in a given stadium, local data is deleted to prepare the hardware for the new game.

All Boundary Cameras are clipped snap to whistle for every play and stored on the New York database for multiple years. These clips are shared with the clubs along with snap to whistle clips of all broadcast angles for each game the following day.

The Broadcaster Factor: Seamless Integration Brings New Looks to Viewers 

Throughout this process, Perez and co. had to be cognizant of how all of these video enhancements would impact – and potentially benefit – the league’s broadcast partners. Among the major challenges: working through a solution to share the Boundary Camera feeds with broadcasters.

“We needed to find a way to hand off 12 feeds without amassing large infrastructure footprints for 12 copper lines to the truck dock or the need for the broadcasters to bring on more operators for these cameras,” he says.

In the end, the NFL worked with broadcasters, Sony Hawk-Eye, and Officiating to provide these cameras via the league’s Under the Hood feed to the truck.

“Broadcasters have found this very useful for some of their smaller production trucks on Sunday afternoons,” says Perez. “And the feeds have been shown on air multiple times already this season.”

As for the Virtual Measurement is handed off via the same copper IO panel at the truck dock.

“The network partners worked closely with Hawk-Eye and our Broadcasting team here at the NFL to design the graphic we all see at home today,” says Perez, “one that continues to have minor adjustments throughout the season.”

This graphic is produced as soon as Art McNally GameDay Central completes their measurement and triggers the graphic. Broadcast trucks and stadium control receive the feed simultaneously to share with the fans in the stands and at home as well as all the players, coaches, and officials on the field.

There is also a connected smartwatch watch worn by the two line of scrimmage officials (the down judge and line judge) that receives a notification of the virtual measurement result through our on-field Verizon Private LTE network. The notification comes a few seconds ahead of the broadcast/in-stadium graphic in order to give head coaches a jump on player substitutions in advance of the following play.

Hawk-Eye in the Sky: Sony and the NFL – Brothers in Technology Arms  

Sony and its Hawk-Eye Innovations team are at the core of the NFL’s Virtual Measurement, Boundary Cameras, and SkeleTrack operations. It’s just one aspect of a wide-ranging relationship between the league and the technology behemoth, which also includes collaborating on coach’s headsets, personal audio for players and fans, cameras and imaging, and Beyond Sports data visualizations.

“Our relationship with the Sony Hawk-Eye team has evolved meaningfully from a foundational model focused on replay infrastructure and software support into a broader innovation partnership. What began as a very replay-focused collaboration in 2021 blossomed into a shared commitment to pushing the boundaries of what’s possible in football operations and officiating technology.”

Perez cites the introduction of bespoke sideline headsets, designed in close collaboration between Sony engineers and our coaching staffs, as another key development. These headsets have undergone rigorous real-world testing and are receiving strong positive feedback from coaches, according to Perez.

“Beyond hardware, the Sony Hawk-Eye team has shown a consistent willingness to co-develop solutions that address real challenges on the field,” says Perez. “From Virtual Measurement to replay support, Sony-Hawkeye’s openness to iterative feedback and their responsiveness to our operational needs have made them a valuable partner as we continue to grow together as innovators bringing efficiencies to officiating, value to clubs, and greater insights and media enhancements to the fans.”

Mid-Season Report Card: A Success Story With Plenty of Room to Grow

At the regular season in the can, Perez says that both Virtual Measurement and Boundary Camera usage has been successful thus far. Heading into Week 12, the boundary cameras are used an average of four times per game as part of the replay process and Perez expects that rate to increase over time.

The league has also seen a handful of virtual measurements and Perez says that efficiency for that process has improved over the old-school chain gangs – clocking roughly 20-25 seconds faster with virtual measurement.

“There are still operational and software optimizations to be made to continue to speed up the process, but we are happy with the direction we are trending,” says Perez. “And our early tests of SkeleTrack data quality across our games – including international games – have been positive and we are excited about the broad spectrum of opportunities we have with that robust data feed.”

With the infrastructure now in place at all 30 NFL venues, Perez and his team are constantly evaluating new ways to become more efficient and find new applications for the technology.

“We are always looking to develop enhancements to the current infrastructure,” says Perez. “The goal is to build supporting infrastructures that allow for sharing more insights with clubs, solving some of our most difficult officiating challenges and optimizing the fan experience.”