HereLink Real World Range Test

#1

Along with a bunch of other tests, I wanted to do a range test on my HereLink before we decide if we are going start using them in our products. I simply mounted it on a Bixler aircraft that already had a pixhawk flight controller installed, mounted one antenna to the side of the aircraft body and the other antenna out on the bottom of the wing. I went to as open of an area as I could where I live. I started the flight on a soccer field, and headed over to a golf course. My altitude was about 175 feet and I was almost exactly 1 mile away when I lost connection completely. I tried this a few different times flying in different directions and lost connection at about 1 mile in every direction. I have seen a range test going out 15 kilometers, but I know that was over open water. I was hoping to at least get 2 miles away before I had a connection issue in a normal environment.
My HereLink ground unit was set to FCC standards through the menu.

Any advice on increasing the range and is anyone else out there having range issues?


HereLinkFlight-KMZ.zip (219.6 KB)

Video of my flight:

Connection dies at ~2:20 in the video and the aircraft switched to RTL. There was actually about 20 seconds between when i lost connection and got video back, but apparently YouTube just thought this frozen part of my video was not supposed to be there and removed it…

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#2

Do you have photos of your antenna position on the aircraft?

#3

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#4

I know I could place the antennas further out on the wings, but the eventual goal is for this to go onto a quadcopter where I wouldn’t have the advantage of the long wings.

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#5

I may try and put one of the antennas facing backwards to see if that increases my range, but from the datasheets I have seen on these antennas there doesn’t seem to be any directional to them.

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#6

There was some discussion about this recently and the general consensus is that the way you have yours mounted is wrong.

Please see diagrams in this thread

I’d love to see what results you get if you do reposition the antennas as per the diagrams.

As an aside, I don’t know which country you are in or what regulations are like there but flying experimental control systems over a built up area (even if it’s just a bixler) doesn’t seem all that responsible to me.

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#7

jcarff

Excellent work, please try increasing the altitude may be you may get better range. Please also try different antenna placement. As far I am aware the Herelink antenna is omnidirectional, so the placement of the antenna should not affect the range a lot. Best of luck and please report back we are all eager to see what can be achieved in the urban area.

#8

Duncan_Hine

Please do not criticize where others choose fly, without knowing if they are adhering to the countries laws. Please try to encourage people trying to better the RC world, and overall be to the point and please keep your personal comments to yourself.

Thank You.

#9

I am not really sure I understand the diagram. If I am looking at the right one, it simply says to place your antenna at 15 degrees. Doesn’t mention anything about 2 antennas and how they should be oriented relative to each other which I think is the more important part. Even though these antennas should be omni-directional, I am going to pretend they are directional and mount them accordingly and see if my distance increases.

As for flying over built up areas, I completely understand, but this was actually a requirement of this test. I am working closely with the FAA, and local and county law enforcement developing drones for search and rescue as well as for tracking fugitives. They currently have a few custom drones up in the sky but are asking for HD video transmission, and also a wanted a bit more range. I went out to our test range with our hexacopters to test functionality of the HereLink on those but that only allows me to fly about a half mile before I would be over houses. I figured the safest way to test this over urban environments, where the police mostly operate the drones, is to put it on a foam aircraft vs the large hexacopter. Just in case something did go wrong, I had people setup in the two neighborhoods I was flying over on my way to the golf course. I also had a well tested 915mhz telemetry link on board in case the HereLink malfunctioned or wouldn’t reconnect, I could use my tablet to command the aircraft to follow a pre-made mission that would have landed it in the golf course if the need arises. Normally I wouldn’t fly over houses if I can avoid it, but I made sure to take as many precautions as I could with this flight as it was necessary to see if the HereLink could operate in noisy, obstructed real world conditions before I will consider using the HereLink in future production drones.

Also I would have gone higher to try and increase range, but decided to flying at 175 feet because that is the normal altitude that the police are flying their drones as their main operational location is in class C airspace and they are limited to 200 feet in much of their area.

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#10

Antennas need to be 0-15 degrees from vertical.

Omni talks about around the antenna, not above or below it.

Think of a doughnut, around the antenna…

The manual shows the setup angles

#11

By no means a criticism. Merely an observation. This is a public forum where folk come to learn. Others may look at the map and assume it’s ok to fly in the same way. They may not take the same precautions as the OP

One incident in a built up area will undo years of work done by all those in the community. This is me trying to better the RC world.

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#12

I agree with Duncan, better it’s pointed out…

As the OP had all the right waivers etc, that’s great,…

HOWEVER!!!

HereLink is BETA!!! So there is not a risk assessment in the world that should have allowed this flight. Especially as the OP had not followed the quick start guide which shows antenna setup.

@Ganesh, I didn’t take @Duncan_Hine’s comments as harsh, and I doubt the OP did either, he is a professional, and will take a bit of advise on the chin.

#13

Let place both antennas vertical at the same side of the body, at least 20 cm distance between two those antenna, and you will see difference

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#14

Even though the OP responded I might add I am jaded with reading these comments in this context, TBH. The risk that Bixler presents is utterly negligible. How on earth are we to get this kind of real-world data if people do not test in this real-world environment. He was using a foamy FPV plane setup correctly with failsafe. Edit – well my comment was superfluous as I read through all the full thread.

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#15

I didn’t take any comments as harsh, and I think it was right to voice concerns about flying this over the area I was flying.

As for the antenna placement, I did see the quick start guide, but as I said, unless I was missing something it only shows single antenna placement and I wouldn’t expect you would want to place both antennas on the same plane at the same 15 degrees. I was simply wondering if there was a tested setup that worked best for these 2 antennas.

I did look over the data sheet for these antennas and now looking back over them again I see that I did miss-interpret some of the radiation patterns.

AntennaPlacement

While it didn’t make any logical since to me, when I first read through the datasheet for these antennas, I thought that the radiation patterns were fairly even among each axis, but I see now that along the Z axis there is a significant reduction in power. I am going to modify my antenna placement accordingly and give it another go.

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#16

Awesome! Yes, though the QuickStart shows half the vehicle, it implies two antennas both 15 degrees from the vertical, the drawing is to imply the setup is mirrored on each side of the vehicle.

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#17

Hi Marc

We are in an era of intense scrutiny, fake news, and exasperated fear. Though I totally agree that the bixler itself poses a low risk to life, the fallout to us as a hardware vendor, or Ardupilot as a project if this was to go wrong is at an absurdly dangerous level.

If no drones at Gatwick can be used to cause the chaos and unnecessary damage to this industry, imagine what damage a bixler “crashing” into a moving car, a bus, or heaven forbid, a school… regardless of if anyone is hurt or not.

We live in a society driven by fear and hate.

Risk is not only about risk to life.

We do not certify our products, especially our beta testing for flight over populous areas. If your operations are doing this, you are operating outside of our guidelines, so it’s 100% up to you to manage that risk.

Philip

#18

Hi Philip,

Exactly I agree with your risk assessment of HereLink and the cube, that is why I have them grounded. Just kidding take it easy we are all mature people here, and risk cannot be eliminated completely even when you fly on the moon, there is a probability you may hit something. We can only minimize the risk.

But as pointed out @Marc_Dornan and me we need this sort of data to test the metal of Herelink and the cube.

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#19

Long range tests can be done anywhere… over people is not needed!!

Feel free to chat with the lawyers we deal with if you feel that we are being too precious on this. Or better yet, please pass your cc details to our lawyers so they can bill you :slight_smile:

This isn’t something we can just ignore and hope it goes away.

Let me make this perfectly clear.

FLIGHT OF ANY OUR GEAR IN A MANNER THAT MAY BREACH SOC AS DEFINED BY CASA IN AUSTRALIA IS 100% AT YOUR RISK

IT IS YOUR RESPONSIBILITY AS THE PILOT IN COMMAND TO DO A FULL RISK ASSESSMENT OF EVERY FLIGHT BEFORE TAKEOFF, YOU MUST UNDERSTAND THAT SYSTEMS FAILURES DO OCCUR ON ALL ELECTRONIC SYSTEMS. BETA SYSTEMS ARE ESPECIALLY UNPREDICTABLE.

FAILURE TO OBEY THIS DIRECTIVE MAY LEAD TO DAMAGE, INJURIES OR DEATH.

If you don’t like that, sorry. But it’s the world we live in.

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#20

Hi jcarff

I have been thinking about this and wanted to put out a diagram, but you have done it thank you. I did have my Hereink antenna mounted along the z axis, when I was testing it. But according to @Philip you have to mount it along the Y axis with the 15 degrees offset facing the ground on each side of the craft.

When we a flying the craft is either flying away or towards us most of the time. This means the donut effect of reception area will not cover the controller? Please try it out and keep all of us informed.

Great job, you have done so far. I wanted to try this my self with my trusted Mi drone by piggy backing the Herelink but was concerned about the power draw, and safety issue raised. Also not happy to destroy my trusted flyer for the time.

Excellent work, thank you for sharing your work.

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