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M210-RTK (v1) near cell towers and other RF/EMI sources
568 8 2019-8-5
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BvdM
lvl.4
Flight distance : 233950 ft
Netherlands
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Dear all,

I’m curious to hear and learn from others flying a M210-RTK v1 (or a regular M210/M200 for that matter) near RF/EMI sources, and cell towers and particular. We are opting to model these structures, hence flying as close as possible is much desired while the use of optical zoomcaera’s is hardly an option.

There’s plenty of examples out there demonstrating the impact of RF/EMI on flight behavior (even at a distance) is very real, but there’s a similar number indicating there may be none of such impacts either. The M200-series being a seemingly ‘rugged’ platform for flying in areas with increased interference I’m particularly interested to know:

- What are the odds to encounter issues such as signal interference, complete signal loss, GPS loss and malfunctioning of any other onboard electronics? And to what extent are the M200 v1’s supposedly shielded to limit or even prevent these issues from arising?
- How should the output frequency of individual antennaes be interpreted with respect to how likely they are to interfere. Any frequencies in the 2.4GHz and 5.8GHz range are obviously more likely to interfere with the C2 and video up-/downlinks, but what about other frequencies?
- Likewise, to what extent are adjacent frequency bands considered isolated to one another, and vice versa? E.g. is a 2.6GHz antenna just as (un)likely to interfere as a 20GHz antennae, or does the former pose a higher risk due to it being ‘closer’ to the 2.4GHz and 5.8GHz bands?
- Microwave dishes are considered to be particularly troublesome, but for what exact reasons and to which degree?
- Taking all of the above into consideration what would be considered a ‘safe distance’ to operate in? Are we talking a couple, tens or even hundreds of feet?
- What auxilliary precautions should one take, in addition to defining an adequate RTH-altitude, to minimize chances of interference or to limit the impact thereof in case it still occurs?

Thanks in advance!


2019-8-5
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Matthew Dobrski
Captain
Flight distance : 1616188 ft
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Canada
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This is interesting issue, the scope of which - unfortunately - is difficult to outline within precisely determined boundaries. The manuals of every DJI drone clearly warns about flights in proximity to any radio wave emitting structures, period. What is the nature and power of such emission will be the deciding factor, but the drone may - and eventually will - switch to Atti Mode unexpectedly. Just yesterday I was filming a small tug boat with typical Garmin rotating radar system, and couldn't get closer than 100 m with my M200 without messed GPS and/or compass. That said, more advanced versions of M200 series are advertised as particularly better equipped to deal with such interferences, but ... Mastering ATTI flight and be prepared for such is the best strategy. Make sure you have enough space around to execute ATTI maneuverings, shot your machine straight up full throttle when it happens ...
Finally, perhaps very competent Facebook DJI Enterprise Solutions group will be able to respond with better answers and advices.

EDIT: Ignore last sentence, I see you're already on FB with this ...
2019-8-5
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MedicFL1
lvl.4
Flight distance : 3718527 ft
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United States
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The Matrice 210 RTK has also lost signal on me on a few occasions, but for the most part does well in EMI situations.I purchased it because of the Inspire 1 V2 Pro behavior around EMI and have been satisfied.
I highly agree that one must Master ATTI Mode and know not only their equipment behavior but also your surroundings and options for getting out of emergency situations.
     As an example, i lost transmission signal long enough so that the Flight Record was split into TWO different Flights with two different HOME Points. AirData shows the results but no one knows why as i had flown this area many times.
Keeping LOS and Being able to handle your uav in ATTI mode are the safest things you can do.
It is a safe uav for the most part and able to handle EMI but it pays to be ready for the unexpected - which MAY happen. Again, it does not happen a lot by any means.
2019-8-5
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BvdM
lvl.4
Flight distance : 233950 ft
Netherlands
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Alright so we just conducted some initial tests and the outcome was somewhat interesting, to say the least. The tower of interest embodies different antennae at two different altitudes. The lower ones at 111ft AGL outputting 935.2-944.8 MHz (@23.8 dBW) and 816 MHz (@26.6 dBW) while another set at 124ft AGL outputs 2.127 GHz (@28 dBW), 1.815 GHz (@30.5 dBW) and 2.660 GHz (@31.2 dBW) respectively.

Considering this was an initial test we purposefully took it slow and opted to see what would happen (if anything) from what we considered a relatively ‘safe distance’ first. Starting at approx. 60ft from the tower we gradually moved the bird upwards while maintaining the same lateral distance. For what it’s worth; prior to take-off there were no RF related error messages, Radio Channel Quality was classified as ‘good’ and signal strength was maxed at 5/5 bars.

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2019-8-6
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BvdM
lvl.4
Flight distance : 233950 ft
Netherlands
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When the Operating Frequency in GO4 was set to 2.4GHZ (2.400-2.483) we encountered zero issues at first when flying in front of the lower antennae. However, as soon as we reached the altitude of the upper antennae at 124ft our signal was affected immediately, indicated by subsequent warning messages and the signal strength dropping from 5 to 2 bars straight away.Note that we weren't even flying directly in front of the antenna, but rather 10-20 degrees off-centre. As soon as we flew a couple of feet higher or lower the signal strength would reset to normal, only to be lowered again as soon as we moved back in front of the upper antennae. At this point we aborted the flight and refrained from flying any closer to prevent a further loss in signal strength and possible RTH initiation.

*Post continues below*
2019-8-6
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BvdM
lvl.4
Flight distance : 233950 ft
Netherlands
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So in contrast to popular believe it seems that inference may even occur from frequencies other than the operating frequency of the UAS itself considering none of the antennae frequencies (1.8GHz, 2.1GHz and 2.6GHz) aligns with the UAS’ 2.4GHz frequency. Interestingly enough when looking at the flight records in Airdata there’s no mentioning of signal loss/interference whatsoever. According to Airdata signal strength was 100% throughout the entire flight although GO4 clearly indicated otherwise.

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2019-8-6
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BvdM
lvl.4
Flight distance : 233950 ft
Netherlands
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We then changed the Operating Frequency to 5.8GHz and conducted a similar attempt at 60ft from the tower and, somewhat surprisingly, encountered no signal-loss related issues whatsoever. Even when we gradually closed the distance towards the tower from 60ft to approximately 35ft signal strength remained at 5 bars and no interference error messages occured. We then set off an orbital flight at 30ft from the tower starting approximately 20ft above the highest points. All went well during the first orbit but the second orbit saw a sudden loss of the D-RTK signal, resulting in the orbit being paused, the UAS switching to regular GPS and the orbital flight eventually being continued. Please note that at the time RTK was lost the basestation had an uninterrupted line of sight towards the UAS and the distance between the base and UAS was seemingly short (approx 150ft).

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2019-8-6
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BvdM
lvl.4
Flight distance : 233950 ft
Netherlands
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For now we are somewhat dissapointed by the M210-RTK's performance considering it's "rugged design" was, supposedly, meant for applications and operating environments mentioned here. Furthermore the cell tower that we visited today may be considered rather 'simple' with respect to how many antannae and frequencies it operates on; most cell towers in this region carry significantly more antennae (including microwave dishes) while operating at even more frequencies too. There's still a lot to be sorted out first before we may even consider flying near these towers (again).

*The end*
2019-8-6
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NickLiUpair
lvl.2
United States
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BvdM Posted at 8-6 12:38
For now we are somewhat dissapointed by the M210-RTK's performance considering it's "rugged design" was, supposedly, meant for applications and operating environments mentioned here. Furthermore the cell tower that we visited today may be considered rather 'simple' with respect to how many antannae and frequencies it operates on; most cell towers in this region carry significantly more antennae (including microwave dishes) while operating at even more frequencies too. There's still a lot to be sorted out first before we may even consider flying near these towers (again).

*The end*

Have you ever tried products from MMCUAV?Their drones have good anti-electromagnetic interference capability and they are the largest industry UAV supplier of State Grid.
2019-8-12
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