Hi all,

I just want to share my personnal experience as regards the range of my P3S, and the factors that could influence on it, and more precisely : trees.

I've noticed that when flying on a very opened area, like a field, with absolutely no tree at proximity, I can reach the best range possible : approximately 400m long/150m high, which is what mostly P3S owners get (I just can't understand how several P3S owners manage to go much further in CE mode (like 1000m or so), but that's an other question ;)

But when flying in an opened area bordered by trees (like in a wood, where there is a little area without trees but just simply grass), my range will radically be redcued : I never manage to go further than approximately only 120m long, and 80m high, which is a bit annoying.
It's a bit as if the trees would "absorb" the wifi signal and reduce its strength...

Of course, the range we can obtain can vary a lot from one place to another, depending of possible interferences, power lines, close proximity of cities and so on.
But as regards my case, I think both areas seems to be the same : far away from city, no power lines, etc... so equal as regards the interferences... the ONLY difference I can imagine between both areas is the presence of the trees.

Is that particular impact of trees something you've also noticed about the range?
According to my personnal experience, that seems obvious. But I'd like to know if I'm the only one, or if other pilots have encountered the same behaviour and conclusion

Thanks a lot for your feedback!

Regards,
Julien

Hi Julien
I am one of those PS3 owners that manages to get to around 800 - 1000m distance at around 100m altitude on open fields.  I do this regularly as live in the countryside.  
As I'm in the UK I imagine I'm automatically in CE mode as that's governed by GPS location.

I have found the angle of the RC antenna crucial to getting these distances. These areas have plenty of trees too around the edges, but I make sure I always have a direct line of sight to the drone and the trees along the edges of the fields make no difference.  Always having a clear line of sight and always moving the RC antenna to be at right angles to the drone (ie never pointing to the drone) makes a huge difference.

Ian

Not to offer this as an explanation, but for general information;  yes ,  trees can have a dramatic effect on rf  ( radio frequency ).   Pine trees ,  in particular,  will attenuate the signal,  especially the higher frequency stuff,  like what the Standard uses.  2.4ghz for video and 5.8 for control.  It has to do with the moisture in the needles.   The human body is also a good blocker of rf.  And,  naturally,  any metal or other structures.  Anything that is in line of sight between you and the P3 will affect it.
Then,  there is local rf interference,  and,  not to forget,  solar activity.  All things will affect the range.  I first bought a Standard,  but quickly got frustrated with the range.  I ended up buying an Advanced.  Bone stock,  here in the mountains where I live,  I have regularly flown out to over 13,000 feet.  That is plenty far enough for me.  Conditions are really good here,  but still,  under certain circumstances,  I do get reduced range.

You can get antenna modifications that will extend your range.  In fact,  you can make your own out of a few cents worth of materials.  There are videos on youtube about this.  I believe they are called,  Do it yourself windsurfers.  They require no modification of the r/c or aircraft.   I have not used them,  but the science behind them is sound,  though they mostly affect the control signal.  To get longer range video signal, you have to mod the controller.

Hi wellsi and Kneepuck, and thanks for your answer!
@ wellsi : I've already pay attention at the antenna orentation. But did not really manage to find what is the best orientation that drastically changes the results. What are your conclusions?
@ kneepuck : will the windsurfer extend both the control and video signal, or only the control signal?

Absolutely!  VHF/UHF signals are absorbed (actually blocked) by vegetation. How much, depends on what kind of vegetation.  Trees, in the summer, full of moisture, can totally block signals.  In the winter, depending on the type of tree, the same tree can slightly attenuate but not block the signal.  Yes, you can expect greatly reduced range in the summer when things are greener.  The advertised range of these drones should be considered under ideal conditions.

Thanks for your aswer!
Just to be sure I made myself clear : is it also true when there is no tree directrly between the drone and the RC?

Indeed, it is clear that if there are some trees between the RC and the drone, the strengh of the wifi signal will be reduced. Of course, the more obstacles the signal go through, the more the signal is attenuated. That seems obvious.
But in my case, I'm describing a situation where there is NO obstacles bewteen the drone and me.
To describe it schematically, let's say I find myself in the bottom of a circle of a radius of 40-50m, where the trees are that circle. And the drone is flying in front of me, that means into that circle. That means I have trees just behind me (but these are not in the direct way to the drone), and other at distance of 80-100m, just under the drone that is flying above, at 70-80m.
Trees do never represent a direct obstacle between the drone and me.

So just to understand : in that situation, does the wifi signal also get absorbed by the trees, even if they are not in the way beween the RC and the drone?

make a cheap and easy antenna booster.
http://forum.dji.com/thread-23565-1-1.html

julienphoto92 Posted at 2016-4-10 16:21
Thanks for your aswer!
Just to be sure I made myself clear : is it also true when there is no tree d ...

No, the signal should be good.  However, be sure that you properly align your antenna with the drone, especially on the P3S.  i.e. Even in my case with a P3A, if I stand the antennas straight up and down and climb straight up above me, I'll lose signal intermittently at 400 feet.  RC antenna(s) need to be parallel with the drone as much as practical.  They radiate and "hear" directly out from the sides (flat sides on the P3A/P3B) of the antenna.

julienphoto92 Posted at 2016-4-10 12:59
Hi wellsi and Kneepuck, and thanks for your answer!
@ wellsi : I've already pay attention at the ant ...

Because the Standard uses 2 different frequencies to operate,  5.8 for control and 2.4 for video,  it is tough to extend the range on both.  The external antenna on the remote is for the control signal.  That is what you install the windsurfer on. Inside the remote there are 2 flat panel antennas for the video. I think some of the systems you have to purchase bring those internal antennas outside the r/c as part of the modification.  But,  it requires modding the r/c which will void your warranty.  
That being said,  on my Standard,  the range of the control signal was the primary problem for me.  The video signal I did not lose.  It was better than the control signal by far.

I think one thing the OP is saying is not being fully understood. The trees he is talking about are not between the RC unit and the Aircraft, they are around the edge of the field. He is asking if they can 'absorb' the radio waves (as I understand it) . And the answer is no, the trees will absorb the signal if they are between the RC unit and aircraft, but not if they are surrounding the area.

AG0N-Gary Posted at 2016-4-10 15:42
No, the signal should be good.  However, be sure that you properly align your antenna with the dro ...

True that the signal will work better if the antenna on the remote is parallel to the antenna in the legs of the P3.  However,  these are dipole antenna,  if I am not mistaken.  In fact,  on the Standard,  I know for a fact that it is a dipole antenna,  since I have removed mine and installed an external antenna.  The point being,  dipole antenna does not care if the flat side or the rounded side is aimed at the P3. Just so long as it is vertically parallel to the P3.  Adipole antenna like this is used for 360 degree horizontal radiation.  It is not very effective directly overhead. It radiates like a doughnut, and doughnuts have a hole in the middle.  If you use something like the Windsurfer antenna,  what that does is make the signal directional,  by reflecting the radio waves in only one general direction. In that scenario,  it is critical to have the antenna pointing directly at the Phantom for best performance. At the same time,  if the Phantom gets alongside you at any distance,  it will probably go rth,  even if fairly close. Because the majority of the signal is reflected to ahead of the r/c,  not alongside.
This is a pretty basic description of how antennas work.  If you are interested in learning more,  I suggest the ARRL Antenna handbook.  It is probably the most comprehensive work available on antenna technology.

Kneepuck Posted at 2016-4-10 18:05
True that the signal will work better if the antenna on the remote is parallel to the antenna in t ...

The point being,  dipole antenna does not care if the flat side or the rounded side is aimed at the P3. Just so long as it is vertically parallel to the P3.

Correct.  I thought about going back and correcting what I had said about the flat side, but never got back to it.  Also, there is a possibility that there would be some benefit to keeping the flat side toward the drone to keep away from any pattern distortion brought about by the two antennas being parallel to each other.  I haven't bothered to calculate wavelength separation of the two, but it could have an effect on the overall pattern of the antenna system.  I don't know the exact use of the antennas, but I've seen it stated here on the forum that control is on one and FPV is on the other.

AG0N-Gary Posted at 2016-4-10 19:07
The point being,  dipole antenna does not care if the flat side or the rounded side is aimed at th ...

That would be consistent with the way it is done in the Standard.  But the Standard uses 2 antenna internal to the r/c.  When you think of it like that,  it really gives a greater appreciation for the Lightbridge technology.  Both control signal and fpv on the same frequency range, ( 2.4 ghz ),  and still I am getting over 13,000 feet distance with only minor video glitching at max distance.  The only reason I have to turn back to home is battery considerations.  I usually land with anywhere from 15 to 20 percent remaining.

Kneepuck Posted at 2016-4-10 23:34
That would be consistent with the way it is done in the Standard.  But the Standard uses 2 antenna ...

At the risk of a duplicate post, since the last one didn't seem to work....

One of these days, I'll gather up enough balls to run mine out to maximum and see what it does.  I'll have my wife in the p./u, with radio, to keep track of what it is doing.  

AG0N-Gary Posted at 2016-4-11 16:09
At the risk of a duplicate post, since the last one didn't seem to work....

One of these days, I' ...

No balls needed!   RTH works fine!

To the OP, there are two antennas;  one inside the RC and the flexible
pointy antenna.
to be clear, face the drone, with the RC in front so the internal antenna is
face on to the drone ( (as it's along the back edge of the RC).
Then also ensure the adjustable antenna is perpendicular to the direction of the
drone. Never pointing end on towards it.

Trees around the edge of the field should not really impact the signal your drone is
receiving. Radio waves travel in straight lines.

And finally I tested my "windsurfer" and threw it out after a few goes.
Made no difference at all.
ian.

Thanks a lot all for your answers!
So I understand that if there aren't trees between the drone and me, these trees may normally NOT impact the range.
So maybe there is an other thing (that is not obvious to me), that would explain why I can reach more than 400m in one area and not much than 100m in an other.

Julien