The following site huntthesignal.com is up and live. It appears to only be compatible with mobile devices. If you access it from a computer the following page is shown.
When accessing from a mobile device, you get the following page. The page appears to work off of your devices accelerometer, which is why the page will not work on a computer.
I did play around with this for awhile today. I did not appear to give me any sort of notification or blips on the screen. As the bottom indicates if you move around you will get some varying degrees, hence why it is only active for mobile platforms.
More to come on this.
UPDATE: So according to one of my NEC Mates 27, 117, and 248 are the magic numbers here. Once you are on them it will load a progress bar, after that you’ll see a transmission from Spartan Locke, then a login page. You will then need to be registered with the site, and then be prompted to either Create a Team or Join one. I have created one for the site, the info is below.
Team Name: THA
Code:THA117
The Halo Array 
Hey there, just to let you know, you’re quite a bit behind. The compass part was the very first thing that went live two days ago. Here’s a link to a recap so you can catch up ^^
https://www.halowaypoint.com/en-us/forums/6e35355aecdf4fd0acdaee3cc4156fd4/topics/huntthesignal-discussion-thread/bc3af2a9-66e8-4d5c-8fc3-27668c0e9a99/posts
Doesn’t matter if I’m behind. Still cool to know. I don’t frequent Waypoint much, but thanks for the info.