A Tesla Semi prototype and a Cybertruck prototype were spotted with a massive new lidar sensor in the front – likely to ground truth data for the Autopilot/self-driving sensor suite on those new vehicles.

Lidar stands for Light Detection and Ranging, and it is a method for determining ranges by targeting an object with a laser and measuring the time for the reflected light to return to the receiver.

Tesla has taken a different approach and is instead betting on pure computer vision using cameras.

CEO Elon Musk has often said that lidar technology has been overblown and has described it as a distraction to achieving full self-driving capability.

But Tesla still uses lidar for its Autopilot and self-driving effort, but it’s not in its sensor suite on its actual vehicles. Instead, Tesla uses lidar sensors on prototypes for the process of ground truthing its own sensors.

When rumors of Tesla using lidar came up after those prototypes were spotted, the company commented:

The claim that Tesla may be planning to use LiDAR as part of its self-driving hardware suite is fundamentally untrue. We regularly test our own technologies against other sensors to calibrate our camera, sonar and radar system.

What’s interesting about those prototypes is that they are often spotted when Tesla is testing new sensors or new vehicles.

Now, a Tesla Semi electric truck was spotted driving around Palo Alto with a XenomatiX solid-state lidar:

When Tesla unveiled the production version of the Tesla Semi and started deliveries in December, we noted that Tesla didn’t say a word about the electric truck being equipped with Autopilot or self-driving technology – like all of Tesla’s other vehicles.

But the production vehicle is equipped with Autopilot cameras.

Now this prototype indicates that Tesla is testing the cameras and whole sensor suite for the Tesla Semi.

Additionally, @dad_uff on Twitter spotted Tesla testing a Cybertruck with the same lidar sensor:

This prototype also features a lot of additional sensors – all likely for ground truthing the actual sensor suite of the Cybertruck.

It makes sense that Tesla would be testing the sensor now since the automaker currently has a fleet of beta Cybertruck prototypes ahead of the start of production this summer.