Those Raytheon automatic (missle) defense gun systems are used on many of our Navy ships. The Phalanx CIWS system:
https://en.wikipedia.org/wiki/Phalanx_CIWSPer the above article,
"A land variant, known as the LPWS (Land Phalanx Weapon System), part of the C-RAM system, has recently been deployed in a short range missile defense role, to counter incoming rockets, artillery and mortar fire."
That would be the one in the video above, no doubt. Surprised to read their claim of countering artillery. Really, you're gonna shoot down incoming arty? Good luck with that. Reminds me of a pic I saw once, of 2 civil war rounds that collided in flight.
The guns are fundamentally the same as the M61 Vulcan gatling guns I worked on in Takhli, on F-111's, only radar and computer controlled. 20mm, 6 barrels, fires 100 exploding cannon rds/second. Velocity 3450fps. 1543gr AP or HEI. Bigger gatling type cannon, the GAU-8 on the A-10 tankbuster, 30mm. I later worked for Raytheon as a contractor before I started important work - making Valkyrie parts. The gun's killing range is given as 2.2 miles, while effective range depends on the radar and computer algorithms and what needs killing and is claimed to be 1-5 miles. BTW a similar system replaced the tail gunner on B52's while I was deployed in SEA - eliminating the need for a tail gunner which they asked me to volunteer for. Yeah right. The tailgunner had the shortest life expectancy of all stations. "But you'll get combat pay!"
If they come up with stealth missles these systems would be ineffective. Until there's a replacement for radar.