[TowerTalk] drone pattern measurements Re: Barker & Williamson Model AC - 1.8 - 30

[CJ Johnson]

Phantom 3 Standards have 20min of powered flight and the speed/time will
vary depending on winds. You can also input waypoints and also specify the
amount of time to hover at each point.

Now this topic has piqued my curiosity in the spring when it's warmer to
try this experiment with my P3S.

73,
wt2p

www.wt2p.con

On Tuesday, January 5, 2016, jimlux <jimlux at earthlink.net> wrote:

> On 1/5/16 10:46 AM, David Gilbert wrote:
>
>>
>>
>> I've suggested before that it should be possible to attach something like
>> a Softrock to a drone along with a small 3-axis sampling antenna.  The
>> output could either be stored in memory or fed real time back to the ground
>> via some sort of link.  The drone could be programmed via GPS (or simply
>> positioned via a tether) to run concentric circles around any existing
>> antenna in place at it's normal location to plot the radiation pattern.
>> The result would take into account not only the antenna itself but also the
>> impact of its surroundings (terrain, buildings, other antennas).
>>
>
> I started to work on this using a powered paraglider and a GPS. Actually,
> what you want to do is put the transmitter on the drone (it can just step
> through frequencies and various axes of antennas).  The recording of the
> data gets done at the (fixed) antenna location.
>
> SRI did this with RELEDOP among other systems, hanging the probe from a
> helicopter 30 years ago.  There's another form used for some broadcast
> installations (there's a cool spherical probe that measures both E and H
> fields in all 3 axes at once)
>
>
> There's a lot of complexities in actually doing it.
> 1) you need to be far enough away to get a good pattern, and that
> increases the flight time needed.
> Say you're 1000 ft away, then a complete circle is 6280 feet (or about a
> mile).  If your probe goes 10 mi/hr, that's 6-7 minutes per circle. And
> you're going to want to do different elevation angles, etc.
>
> 2) Wind is a bigger problem than you might think. A 10 mi/hr wind makes
> for a very slow upwind leg. Even 5 mi
>
>
> The DJI Phantoms have a top speed of around 30 mi/hr, which helps a lot.
> They claim an endurance of 20+ minutes, so you can get about 10 miles of
> measurements out of them.
>
> Today, there's all kinds of "programmable path following" too.. so it's a
> lot more practical. You can preprogram the circles (or squares or hexagons
> or whatever) and easily log the GPS data as you go.
>
> It's probably a several month sort of project.
>
>
>
>> I don't think it would take too much engineering or cost to put something
>> like this together, but I suspect that not many people would be willing to
>> pay to cover the hassle of doing so.  Maybe cell tower owners ...
>>
>> I still think it's an interesting idea, though.
>>
>> 73,
>> Dave   AB7E
>>
>>
>> On 1/5/2016 8:05 AM, Chris wrote:
>>
>>>
>>>> ##  whats needed is a ham version of consumer reports.
>>>>
>>>> Jim  VE7RF
>>>>
>>>> Steve and Ward's Tribander comparison book is the closest thing we
>>> have.  Too bad it's so much work to set up a fair antenna test range; I
>>> would love to see dozens of antennas compared.  Of course, it could put
>>> some people out of business....
>>>
>>> Chris
>>> KF7P
>>> _______________________________________________
>>>
>>>
>>>
>>> _______________________________________________
>>> TowerTalk mailing list
>>> TowerTalk at contesting.com
>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>>
>>>
>> _______________________________________________
>>
>>
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk at contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
>>
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>