I don't own a P3 or any drone of any stripe, but I just started watching videos yesterday and I'm fascinated.

So, I'm not even a newbie...I'm pre-newbie.  I'm just intrigued.  Here's my question:

How constrained by line-of-sight is the P3?  

I know, I know, RTFM.  

But guys, as you know, sometimes the "official word" doesn't match reality (that fiberglass ladder you've got that says 300 lbs but actually never failed in lab tests before 700 lbs).  And sometimes the "official word" is driven as much by company lawyers and just basic business prudence as anything else.

I just want to understand what is possible with these things.  Could you sit in your house and fly your P3 around your block?  What if you had one of those signal-enhancing antenna mods?  Even possible?

I'm not going to hold anyone to their word and go try something nuts.  But this craziness here:  



makes me wonder what exactly is the limiting factor.  

I know this device is not a P3, and I'm not asking if a P3 can do all this.  

But can it be operated out of sight at all?  What is it that constrains that kind of flying exactly?  The tablet/smartphone is just displaying video that's radioed from the copter to the controller, right?  So it's not involved in the actual transmission of data to/from the copter, right?

Again, have a heart, I'm ignorant but almost fatally curious.

Nothing wrong with being curious at all and actually its fantastic to be curious about this stuff. Ok my answer might be a little lengthy but bear with me. The Dji Phantom 3 and Inspire 1 use a proprietary technology called light bridge that is essentially a strong video link between the copter and the controller. The common term for this is an FPV kit and allows for signal to be transmitted from the onboard camera to the screen.

There are in general 3 main limiting factors in the distance that the video can be transmitted
1-Transmitter and Receiver Power:This is measured in Milliwatts and varies from country to country and state to state as far as legality. Essentially the more powerful the transmitter and receiver is the further the signal can reach

2-Obstructions: Like you asked you would most likely not be able to fly the quad from in your house simply because the roof would obstruct the signal and minimize or eliminate any signal you would have. Other obstructions include things like houses or elevation changes

3.-Antennas:In general there are 2 types of antennas a directional and omnidirectional. Directional has the advantage of longer range if you carful and the disadvantage that your much more limited in terms of mobility on the ground and can lose signal by just turning around. Omnidirectional has the benefit of versatility and a broader spread of signal but the disadvantage of not as strong of a signal at long distances Like you mentioned some people do fashion their own boosters some of which work. What most of the Diy boosters do is focus the signal of an omnidirectional antenna in one direction essentially giving the effect of a directional.

To answer your main question for sure you can fly much farther than line of sight. The average distance of an fpv kit ranges from around a quarter of a mile to three quarters of a mile depending on the strength and quality. Light bridge at least in the phantom 3 application is rated for 1.2 miles without obstruction. However people have gone much further (look around and you'll see a couple of tests) than the certified range.

To address your question about the easy of transmission data. Most normal FPV systems process the video in the camera itself and send the image data through a digital or analog video signal with no post transmission processing. Light bridge however transmitted raw data from the camera to the device where it is processed on the phone or tablet to provide the image. This is both good and bad as the device can process images much better and the quality of the image on the screen is much better however it is more susceptible to anomalies like heat or operating system issues.

Finally the constraints of that type of flying are usually distance or laws. The FAA requires line of sight so besides that the only limiting factors are the aforementioned things that shorten range.

Hope this helps!!

It's just great video editing.

dorn.michael10@ Posted at 2015-7-17 14:18
Nothing wrong with being curious at all and actually its fantastic to be curious about this stuff. O ...

Nice detailed answer.  Thank you.

"makes me wonder what exactly is the limiting factor.  "
To give you a simple answer ... theP3 can operate much further than you can see - 5 kilometres or more in good conditions.
The battery is the limiting factor.  The P3 can go further away than the battery can bring it back.
There's no need for upgrading antennas.

Fantastic answers.  Thanks very much.

oiltiger Posted at 2015-7-17 21:48
Fantastic answers.  Thanks very much.

All great answers, however the United States government through the FAA has weighed in and stated that for UAV operation that you must maintain visual connection with the craft. This visual observation is unaided without spotting scopes or persons downrange relaying where your craft are at via radio.

First person video as provided by the Phantom is great when it works. Makes things much easier to frame the photographic shot you want. Establishing a good non interfered signal between the craft and controller is key. Having one of the boosted antennas has shown to both increase the range as well as improve on maintaining signal in less than optimum conditions.

Yes, there are people that send their craft more than a mile away and have them return without issue, however in the event of a problem and the craft were to fail and damage property or human life, you can expect to be spending any discretionary income you have on a lawyer to defend yourself from the law suits and any governmental charges that will be filed.

For heavens' sake, do not try fly your aircraft beyond your line of sight. How would you feel if the motors suddenly quit and it fell on someone and hurt them? Once it's out of sight you do not know who or what it might be flying over. I'm with the government on this one: keep it in sight at all times. If you should lose sight of it, press the return home button on your remote control, having previously made sure that you have sufficient height to clear obstacles on the return part of the flight.

Hi Oiltiger.

Welcome to the forum.. You will find that there are some very experienced and helpful Pilots on this forum...,  and don't be scared of asking any question...., basically there is no silly question..we are all here to help each other..

To answer your question..... Michael has basically given a very good answer, and not much more that can be added.

One thing I will say is that personally, in all the time I have flown the p3, I have never really found the Line Of Sight operation a limiting factor, because as you get more experienced, you learn to move/orient yourself or the craft in a specific position, or if shooting video, then stop at specific intervals, reposition/relocate yourself and carry on flying and shooting video, then complete and re-edit the video shots later..

If you are thinking of getting into the hobby, then do it!!! You will not regret it.. Take small steps, learn to walk before running.

Good luck.

Why do people exhume threads almost a year old and imagine the Op is waiting for their answer?

labroides@yahoo Posted at 2016-5-22 13:06
Why do people exhume threads almost a year old and imagine the Op is waiting for their answer?

I'm with you.

malvern Posted at 2016-5-22 20:58
I'm with you.

DOH!   I didn't notice it was a year old......need a stronger pair of glasses.

labroides@yahoo Posted at 2016-5-22 20:06
Why do people exhume threads almost a year old and imagine the Op is waiting for their answer?

Don't disagree, but sometimes a topic for the "by gone days" does bring up an interesting topic to discuss.  It's clear this aircraft is using a different omni antenna (you can see it in the video).  We have no idea what power is built into the transmitter or receiver..  That said, this is some excellent flying (keeping all things in perspective about staying in Line of Sight visually, etc.)..  I don't think this is just editing or someone on a motor bike staying underneath it the whole time (suppose it could be for "some of it")..

There's also a "seasonal" aspect to transmission and reception.  The trees are all in full bloom here now pretty much in New England, and stock, will have an effect on expected flight ranges unless altitude and line of sight angles are maintained.

It does raise a question also I've been recently thinking about.  The DJI videos on proper antenna useage always show the radio signal on the aircraft as radiating off two sides vs. all four (omni)..  Is that really the case or do the antennas in the legs pick up the RC signal no matter which "side" is facing back to the RC?

And again, a really good first reply to the post..