Hi all. Does anyone have knowlage about if humidity or fog will have effects on radio signal quality or strength.
What other factors affects radio signal strength/quality?
Thanks,

Humidity will affect the electronic components in the MP so it might effect signals.

dronist Posted at 2017-8-12 16:59
Humidity will affect the electronic components in the MP so it might effect signals.

thanks dronist - apparently it will affect radio waves specifically -
this i am looking to be clear on (regarding radio waves) because it could explain some image issues (when received to video feed back on devise) that some users complain of.
Is this a likely possibility or not.

Yes, humidity affects the propagation of radio waves to some extent.
Consider this extreme of humidity: Try to make a phone call using your cell phone under water...

MARSAN Posted at 2017-8-13 00:34
Yes, humidity affects the propagation of radio waves to some extent.
Consider this extreme of humidity: Try to make a phone call using your cell phone under water...

hey Marsan - i tried making a phone call under water - does not work - i think i fried my phone... only joking

Next i would like to know how it affects radio waves and what that means to us - how it affects our signal.

Does it affect video signal - what will this effect look like? Could this be the cause of that wavy pattern accross the device screen sometimes? what do you think?

Bekaru Tree Posted at 2017-8-13 04:22
hey Marsan - i tried making a phone call under water - does not work - i think i fried my phone... only joking

Next i would like to know how it affects radio waves and what that means to us - how it affects our signal.

Post a video so we can see whats going on. I doubt humidity would significantly affect signal strength for our purposes and radio frequency bands. Wavy effects are generally the gimbal being overextended due to sudden changes in AC speed or gusty wind conditions.

Bekaru Tree Posted at 2017-8-13 04:22
hey Marsan - i tried making a phone call under water - does not work - i think i fried my phone... only joking

Next i would like to know how it affects radio waves and what that means to us - how it affects our signal.

The use of a waterproof phone was implied.

If you fly your Mavic in very thick fog or during a massive downpour, you may have problems with the radio signal or simply drowning your Mavic.
But if you want to know scientific evidence of the effect of humidity on radio waves, you should search the Internet.

Ex Machina Posted at 2017-8-13 06:57
Post a video so we can see whats going on. I doubt humidity would significantly affect signal strength for our purposes and radio frequency bands. Wavy effects are generally the gimbal being overextended due to sudden changes in AC speed or gusty wind conditions.

Hey Ex - here is a link to a paper that says humididty and temperature do affect radio waves.
https://jyx.jyu.fi/dspace/bitstr ... csis.pdf?sequence=1
i dont understand the maths of it but their objectives and conclusions are easy to understand - if in fact they are correct, i do not know.
These issues are not related to gimbal overextended and sudden changes in speed - must be something else -

Bekaru Tree Posted at 2017-8-13 08:29
Hey Ex - here is a link to a paper that says humididty and temperature do affect radio waves.
https://jyx.jyu.fi/dspace/bitstream/handle/123456789/53053/rssivsthfedcsis.pdf?sequence=1
i dont understand the maths of it but their objectives and conclusions are easy to understand - if in fact they are correct, i do not know.

Hey Bekaru,

Thanks for passing that along, it was interesting reading. The paper's conclusions are possibly applicable to the Mavic's low-power Wifi mode of flying, but not so much with the most common RC mode which employs nearly 7 to 8.5 times more radio transmission power than standard wifi modules. The paper also concludes that while temperature has an affect upon low-power wifi range, humidity only may have an affect at freezing temps and below.

So while technically hot weather or high-humidity freezing temps may decrease range, I still feel it's unlikely to decrease range to the extent that most pilots would notice, as most pilots don't fly at the extreme ends of their range to begin with.

When you have downlink video problems due to RF range or blockage, you see choppy, stuttering and/or frozen video. Without seeing an example video of the image issues you are experiencing, it's impossible to help diagnose your problem.

Bekaru Tree Posted at 2017-8-12 23:55
thanks dronist - apparently it will affect radio waves specifically -
this i am looking to be clear on (regarding radio waves) because it could explain some image issues (when received to video feed back on devise) that some users complain of.
Is this a likely possibility or not.

We are talking about extremely HIGH humidity like Hong Kong September

Ex Machina Posted at 2017-8-13 11:23
Hey Bekaru,

Thanks for passing that along, it was interesting reading. The paper's conclusions are possibly applicable to the Mavic's low-power Wifi mode of flying, but not so much with the most common RC mode which employs nearly 7 to 8.5 times more radio transmission power than standard wifi modules. The paper also concludes that while temperature has an affect upon low-power wifi range, humidity only may have an affect at freezing temps and below.

great reply thanks. as per yr last para, i do not have this problem much any more and when i do then i go for altitude and reassess my orientation.agreed mavic transmission at 2.6dbm is very good, near top of range.
i partly agree with yr evaluation on humidity but also fog is humidity and this causes massive degradation/loss of signal - i have experianced and as you explained it causes the wavy image - which is what some newbees ask about.
So it is due to degraded radio signal, agreed.
What are the factors that cause degraded signal: antenaes in poor position; brocken or disturbed LOS; electromagnetic interferance and high humidity.
Humidity is directly related to air pressure. Would or could it not be the case that if a mavic quickly flew through varying pressure systems (from warm land into a icy off shore air pocket) that this might confuse the barometer to think it is higher than it is.
It appears that when IMU issues occur then GPS shuts off and ATTI kicks in.
So GPS is off an Atti now dependant on barometer gets a reading that the drone must be higher because of the sudden arrival of cold air and Atti makes height adjustment and wants to come down in height - perhaps this is the cause of some mavic drowning is what i am trying to figure out.

dronist Posted at 2017-8-13 11:32
We are talking about extremely HIGH humidity like Hong Kong September

pardon my ignorance - can you fly in hong kong humidity? curious to know - i guess the answer should be No?

It does affect radio waves.. now applied to the mavic... I wouldn´t say it´s a key factor on signal transmission.

does humidity impact radio waves:  yes... but only over much longer ranges and/or much higher frequencies and/or much more tightly attenuated frequencies than we meer consumers deal with.

i think the proper question to ask is: does humidity impact range and usability of range in regards to mavic pro or other high end DJi drones... and the answer to this is no, humidity alone should not impact the signal over that short of a distance and with such a sweeping band to play with.. and the tuning isnt tight enough that the nearly microscopic attenuations that may occur over that range would make any impact..

ImHereToCrash Posted at 2017-8-13 15:38
does humidity impact radio waves:  yes... but only over much longer ranges and/or much higher frequencies and/or much more tightly attenuated frequencies than we meer consumers deal with.

i think the proper question to ask is: does humidity impact range and usability of range in regards to mavic pro or other high end DJi drones... and the answer to this is no, humidity alone should not impact the signal over that short of a distance and with such a sweeping band to play with.. and the tuning isnt tight enough that the nearly microscopic attenuations that may occur over that range would make any impact..

Good answer, should not affect signal over such a short distance - but then what might have caused that waviness - maybe electromagnetic interferance - it must be something even if its just a temp glitch but i doubt it is this - therefore it is something and i do not mind what it is really just that i will find out what it is.
And what of humidity and the video feed signal - do you think it might have an effect, specifically might it cause a wavy pattern on the image?
Lastly to yr first sentence - what is a longer range (what do you put this at)?
thanks

Bekaru Tree Posted at 2017-8-14 05:56
Good answer, should not affect signal over such a short distance - but then what might have caused that waviness - maybe electromagnetic interferance - it must be something even if its just a temp glitch but i doubt it is this - therefore it is something and i do not mind what it is really just that i will find out what it is.
And what of humidity and the video feed signal - do you think it might have an effect, specifically might it cause a wavy pattern on the image?
Lastly to yr first sentence - what is a longer range (what do you put this at)?

What do you mean by the waviness?   Mirage? Reflection?  

Longer range depends  on many factors like power output and frequencies used.. but in GHz range and “couple of watts”  I would say 10’s of miles before serious attenuation would negatively impact signal.  

ImHereToCrash Posted at 2017-8-15 04:38
What do you mean by the waviness?   Mirage? Reflection?  

Longer range depends  on many factors like power output and frequencies used.. but in GHz range and “couple of watts”  I would say 10’s of miles before serious attenuation would negatively impact signal.

Thanks Crash - yes i do mean the mirage type distortion that appears n the image.

And yes i am well within 10km distance so if not radio signal or video signal delay or lag - then what would it be from?

ImHereToCrash Posted at 2017-8-13 15:38
does humidity impact radio waves:  yes... but only over much longer ranges and/or much higher frequencies and/or much more tightly attenuated frequencies than we meer consumers deal with.

i think the proper question to ask is: does humidity impact range and usability of range in regards to mavic pro or other high end DJi drones... and the answer to this is no, humidity alone should not impact the signal over that short of a distance and with such a sweeping band to play with.. and the tuning isnt tight enough that the nearly microscopic attenuations that may occur over that range would make any impact..

Agree that humidity attenuation is microscopic at these frequencies. And since we're talking digital comm protocols here, any other form of  "radio wave" distortion is also a mute point.

"Waviness" in the image is purely a function of the camera, image processor in the Mavic, and your phone's rendering ability.

Bekaru Tree Posted at 2017-8-15 05:56
Thanks Crash - yes i do mean the mirage type distortion that appears n the image.

And yes i am well within 10km distance so if not radio signal or video signal delay or lag - then what would it be from?

Lag is just latency either in the image processing engine or in the conversion process..  I suggest recalibration the signal of the mavic Pro.. I don’t have a mavic Pro yet so I don’t know how to change how the signal works or force a rescan and auto reconnect like with little WiFi based spark I have.   As for mirage distortion.. you have to screen shot it for us to see and check..  could be propellers are matching shutter speed of cameraa causing ripple effect or distorting it similar to shakiness.. or could be your gimbal isn’t stabilizing properly..   only way to know is video or screenshot of the issue..

ImHereToCrash Posted at 2017-8-15 15:57
Lag is just latency either in the image processing engine or in the conversion process..  I suggest recalibration the signal of the mavic Pro.. I don’t have a mavic Pro yet so I don’t know how to change how the signal works or force a rescan and auto reconnect like with little WiFi based spark I have.   As for mirage distortion.. you have to screen shot it for us to see and check..  could be propellers are matching shutter speed of cameraa causing ripple effect or distorting it similar to shakiness.. or could be your gimbal isn’t stabilizing properly..   only way to know is video or screenshot of the issue..

Thanks crash - currently i do not have a video of it because it only happens to me very seldom. Mostly i see it with other users complaints and was trying to understand what might be causing it.
When i have a video of it i will post again.