Michigan: I-696 Strange Ka Search Group!

[joey_corleone]

Some metro Detroit locals have been following some of my posts and others regarding strange Ka band signals (strong ones at that) all along I-696 from Warren at least until Southfield. My current theory is something to do with the DOT intelligent traffic system.

For anybody interested: This is something I'd love to research, find, and document. If you are interested in joining a group of members here local to the area to hunt this down message or email me. I think it would be fun and maybe we could settle this once and for all.

I'm a ham and know some other hams that are good at DFing signals that would probably love to help us.

I'm talking pictures, possibly even video...the works. Lets get a group together!

- Joey

[joey_corleone]

I have an update! I didn't find THE source yet, but I do have some information. OK if you are in the area you've seen these new "Intelligent" traffic signs. You know, they tell you how long it will roughly take to get to an important part of town given the current traffic conditions. This is all part of the Michigan DOT intelligent traffic system. While hunting for that Ka band tonight on 696 west near Bermuda exit I couldn't help notice that very close to where I get the signal there was a solar panel and yagi antenna attached pointing directly towards woodward.

This is a very difficult place to get close to. Fortunately, you have a very dedicated, gifted, and curious guy to do this sort of dirty work It is difficult because this antenna is mounted on the concrete wall, on the North side of the freeway. If you are Westbound, pass dequindre, you will then go over a hill near the I-75 changeover....when you come down from the hill BANG you get hit with Ka band...problem is this is a merge spot where an on ramp merges with 696 and there is a very small shoulder.

My crazy ass got ONTO the small shoulder and checked this thing out. It is a yagi antenna, labeled as being in the 900Mhz band mounted on the wall pointed horizontally directly up the freeway. The feedline runs into a white box...that wasn't locked : ) Being the curious guy I am I opened the box and found a large ass car battery connected to the solar panel, and some computer interface...I will try to get pictures if I'm brave enough to try this again.

Anyways, my theory is this: There are sensors that are part of the intelligent traffic system. Those sensors definitely include loops in the road that detect how many vehicles are passing and such...the system also contains god knows what else...but the point is there has to be some way for the sensors to get their data to the changeable message signs, and THAT is where this comes into play. I theorize the sensors are sending data to the microprocessor inside this comptuer interface and the data is being beamed directly to the yagi antenna that is on the changeable message sign via 900Mhz.

Now, what this has to do with Ka? I don't know maybe nothing, maybe everything. In spec mode I was consistently showing 34.732Ghz ... MAYBE it is getting some crazy harmonic from the 900 Mhz system I don't know....maybe the box has built in radar capabilities or some inputs on the microprocessor are being fed data from a Ka radar I havn't found yet.

All in all educational night.

- Joey

[joey_corleone]

Update - I have not been getting the Ka signal at and around Bermuda exit since I went investigating the other night ....hmmmmmmmm lol

- Joey

[joey_corleone]

Not that it appears anybody cares, but the Ka at Bermuda seems to have magically vanished....coincedentally it vanished the night after I went inspecting that weird yagi antenna

- Joey