Reducing radar reflections

[Woosie]

I've recently started working on my first simulator setup in my garage. It's semi-permanent, consisting of archery baffle netting on a curtain track (the kind you find in hospitals). Next stage is choosing the launch monitor...

I was going to go with Skytrak, but decided to wait until the PGA Merchandise Show to see if there were any new products. And wow, the Flightscope Mevo+ looks amazing! I have sufficient room to use its "short indoor" mode. But there might still be a problem...

I am well aware of the fact that radar-based launch monitors struggle indoors, and that small metal dots are used to improve the spin measurement. Remember that word, "metal"...

Behind my net is a huge sheet of metal, commonly known as a garage door 😱. I fear that the microwave signal reflected back from the door will swamp the signal reflected from the ball. Are my fears justified?

I researched microwave absorber products, and realised I could end up spending more on these than I would on the Mevo+ 🙄. Water is an excellent absorber of microwaves, so that offers a much more economical option, if I can just work out how to build something which will provide a barrier of an inch or two depth of water between the net and the door.

Has anyone looked into doing something like this?

All ideas gratefully accepted!

Alan.

[Tonysmjc]

I think your over thinking it

I don’t believe the door will matter
anymore than any other wall
or the screen itself

before you go crazy planning water barriers check with flight scope

[grant2145]

Florescent lights and rotating objects like a fan can cause interference

[Dax]

My first set up with my TM was hitting into a net screen combo In front of my metal garage door. It ended up causing a lot of interference. I had a remote session with one of their specialists and he felt he could have done things to overcome the no reads that I was getting. However, I ended up moving my TM to my sim room version 2. Immediately after moving to my new sim location all my issues went away and I did not know if they managed to come up with a fix.

the one thing I learned from the session was how detailed the information is that a radar can read. As soon as he logged into my system he knew exactly how far I was hitting away from the unit and also the exact height for which my hitting area was above level from the TM.

in any event, if you can’treverse and not hit into the door, then I would call FS and ask them if they have been able to overcome the issues we all know will happen.

as someone noted above, fluorescent lights are another no no as are things like fans (this includes the fan inside a projector that is hanging from the ceiling - thus if your projector is ahead of your radar you do need to keep this in mind).

hope this helps.

[Tonysmjc]

Hmm I stand corrected

i didn’t think the metal door would matter

[Woosie]

Thanks for the quick replies everyone!

Microwaves will pass through walls (except ridiculously thick ones), but are reflected by a relatively thin layer of metal, hence my concern.

I knew that fluorescent lights affect radar units (so I'll be using LED lighting), but didn't realise a projector fan might be a problem! The plan is to have a short throw projector about 2m from the net and about 2.6m above the floor. Need to think about this.

Unfortunately, there's no way I can reverse the setup and hit towards the rear of the garage.

[Dax]

My TM is about 9 or 10 feet from my projector and when the projector was 7.5 feet high it interfered. I raised it by a foot or so and no issues.

[codehead]

Could you possibly deflect it instead of absorb it? Sort of like the stealth concept. The monitor is a monostatic radar setup. A wedge of light weight reflective metallic material in front of or attached to your door should do the trick. Maybe a frame covered with foil?

[Woosie]

Yes, deflection is a possibility. I'll have a think about that.

I've spent a large part of the weekend learning about radio frequency absorption. I'm now the world's biggest party bore on the subject 😂. One of the most illuminating sites is

https://www.pueschner.com/en/microwave-technology/penetration-depths

which makes it clear how good water is at absorbing microwaves. I believe the Mevo and Mevo+ use a frequency of 24.5GHz, which penetrates 10 times shorter than the figures in that table. So only a few mm of water would virtually eliminate all of the microwaves from reaching the door, and any which did reach the door would be reflected back through the water to be further attenuated. The difficulty is designing something to hold a layer of water a few mm deep and over 4 sq metres in area. Cardboard is another possibility: a thickness of 10-15cm should be sufficient. Maybe combine the two?

Of course, I could spend £3,000 on a commercial solution, but that would be overkill, and probably also result in an expensive divorce 😳. (It would be cheaper to replace the metal door with one made of glass reinforced polyester.)

[crowerivercommuter]

Hang up a wet blanket

[Woosie]

LOL! Nice one 😂

[Woosie]

I'm going to go the deflection route, as described by codehead . The space between the net and garage door is sufficient to fit a foil-covered board at an angle of about 12 degrees from the vertical, so deflecting the microwaves upwards by an angle of 24 degrees to the horizontal, which will be more than enough to avoid detection by the Mevo+ (in fact, up through the roof!)

Before attempting to build my own "foil-covered board", I may even try the lazy option of foil-backed plasterboard.

[codehead]

remember you may get some diffraction off of the edges of the board, but the power of these returning waves will be greatly reduced.

[tonybrown32]

Reviving this topic..

What are all your thoughts about a garage heater... I hear things with fans can interfere, but I assume that's only when they are in direct line of site or online with where the radar is facing, somewhere in the same "window" as where the ball is heading... Would you think a garage heater (which I assume has a fan inside) could cause interference in the following setup:

• Player has a wall 8 feet behind them when swinging
• Heater would be installed about 8 feet high on the wall behind the player
• Heater would be installed on that wall about 5 feet from the player/3 feet in front of the screen... but outside the edge of the screen.

See photo.. heater would be near/over the door to the left of the screen, about 8ft high or so.. depending on size/clearance from the 9'8" ceiling height

[Dax]

While I can't answer your question, I would not take the chance. Alternative would be to install heater here if it is your only option and then see if you can get a demo to test. I was surprised when I first installed my set-up in my new room where I had the projector come down a foot from the ceiling and caused my radar some issues. Moving the projector up 6 to 8 inches solved the problems completely (I was happy that my fix was that easy).

[tonybrown32]

While I can't answer your question, I would not take the chance. Alternative would be to install heater here if it is your only option and then see if you can get a demo to test. I was surprised when I first installed my set-up in my new room where I had the projector come down a foot from the ceiling and caused my radar some issues. Moving the projector up 6 to 8 inches solved the problems completely (I was happy that my fix was that easy).

Surprising the projector/fan would make a difference being so far above the trajectory/window of the ball... not doubting you at all, but just surprised! I would "hope" that a heater being installed pretty high up, and additionally NOT installed on the same line as the ball trajectory, would make issues or interference far less likely.. but who knows! If that tiny projector fan makes a difference, maybe a larger heater fan off to the side will too...

As soon as I get my Mevo+, I'll have an opportunity to play with it in my current setup in the double car side of my garage along with my projector a couple feet from the ceiling, see how it reacts, and go from there before I move my setup to it's new home in the single stall section. It'll also give me some time to play with it at various distances from the screen etc before I land on a configuration too... now I just need my pre-order to be shipped!