Apple Maps Japan Vans Up Close

Lots of folks are tweeting pictures of Apple Maps image collection vans now that they are blitzing Tokyo. Close up views of the right side are very interesting, showing a measurement device that has nothing to do with image collection attached to the right rear wheel hub and wired through an enlarged customized fender. Can anybody ID what it is? How fun it would be to peek inside the rear seat area to see all the equipment and what exactly is being measured.

UPDATE
I reader sent a link to a Cult Of Mac post regarding Apple Maps van measurement devices. The right wheel item is called a ‘Wheel Encoder’:

The wheel encoder and GPS keep track of the vehicle’s movements and provide “ground truth” to the maps being generated by other sensors.

Matthew Panzarino wrote back in June 2018:

there’s also the standard physical measuring tool attached to a rear wheel that allows for precise tracking of distance and image capture.

UPDATE 2
Related coverage on the WWDC19 Apple Maps Wish List