What FCC Service would apply to this application?

[haankster]

Hello All,

I work for a company developing a short range radar for a drone helicopter. We plan to do airborne testing of the radar by flying aircraft targets in the vicinity of the helicopter, then comparing GPS coordinates with radar measurements. To do that, we plan to datalink the helicopter GPS coordinates and flight data to the target aircraft to aid them in positioning the targets with respect to the helicopter. So, here is the question: What FCC service applies to mobile airborne datalinks? Note that the radar itself will be licensed in the experimental category for these tests, the question is for the datalinks only.

Thanks in advance for any help you can give.

Hank

 

[mikegilbert]

I'd look into any data radio which operates in the ISM (industrial, scientific and medical) band. There are plenty in the 900mhz ISM band available: License-free (900 MHz & 2.4 GHz) Data Radio Modems Good luck with the project

 

[rfradioconsult]

It would depend on the RF link that you will be using, if you are going to use off-the-shelf data links then you should be ok in the ISM or actually apply for a license for your operational band. If you are going to build your own RF link then you will need to apply for an experimental license. You will need to retain a Consultant to assist with this project you do not want to see your expensive project crash and burn due to interference with your flight control systems.

 

[K9WG]

I'd look into any data radio which operates in the ISM (industrial, scientific and medical) band. There are plenty in the 900mhz ISM band available: License-free (900 MHz & 2.4 GHz) Data Radio Modems Good luck with the project

If you go with ISM get the 2.4GHz.

(I speak from experience as a former 2.4GHz data link engineer) :wink:

 

[nd5y]

The FCC has several frequency ranges for flight test data and telemetry. You really should follow rfradioconsult's advice and get professional advice from somebody who knows what they are doing and not from a hobby radio forum. The higher you are the farther you receive. If you use 900 MHz or 2.4 GHz ISM bands for your flight testing near a city you are liable to have too much interference from all the unlicensed junk on the ground on those bands.

 

[nd5y]

You might want to contact AFTRCC - Aerospace & Flight Test Radio Coordinating Council and see if they can point you to somebody who can help.

 

[rfradioconsult]

You certainly don't want to trust your prototype to operating in a crowded RF environment, you would really feel bad if it crashed and took out your local WalMart parking lot.

 

[haankster]

More info...

Thanks to all who replied. I will talk to AFTRCC as well as look at the ISM bands.

Just a point of clarification, though. I perhaps misled you in my initial post. Initial flight testing will be done on small manned fixed wing aircraft. On previous proof of concept flight tests, we mounted the radar in the open door of a Cessna Caravan and flew trajectories in a Cessna 182 toward the Caravan. The purpose of the datalink is to control the trajectories. For example, one test was to approach the Caravan so that the radar was scanned aft by 45 degrees. To do that, the C182 has to fly a precise path relative to the Caravan. Hence, we datalinked the Caravan's GPS coordinates and velocity over to the C182, where it was massaged into directions for the C182 pilot (speed up, slow down, adjust course, etc.).

We initially used a low power (unlicensed) datalink for those tests, but had trouble with the datalink dropping out. That posed no safety problem, but it did mean that our trajectories wobbled more than we wanted. So, now we want to use a more powerful datalink, and realize that we will have to obtain a license for that.

For these tests, there is no chance that the datalink will interfere with the flight controls of any of the aircraft. These are all manned aircraft with mechanical controls. In later tests we will operate the radar from manned helicopters, again with mechanical/hydraulic controls.. Only after those tests are completed will we move to the drone helicopter.

Thanks again for your help and replies.

Hank

 

[902]

I realize I'm getting in late into this discussion, but I echo the opinions who call for an RF professional to assist you with obtaining the most appropriate spectrum. ISM is fine for non-mission critical applications, but are tremendously congested. I want to add one thing: as you are (apparently) a defense contractor, you may also want to investigate spectrum administered by the NTIA, particularly as you approach production.

Good luck - sounds like you're having both a productive and fun time there.

 

[zz0468]

Why would a professional organization be looking to a hobby oriented website for advice?

 

[KE7IZL]

The chopper was described as a "drone" not something someone would ride in. It's likely to be very small, like an R/C aircraft, not something that would "crash and burn" a Walmart parking lot.