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Surveying Near High Voltage Transmission Lines


(Hunter) #1

Curious on users experience operating around high voltage transmission lines. Have a job tomorrow with towers running right down the middle of the entire site… Not as concerned with satellites as I am to my LoRa connection between rover and base. Site is wide open, no trees, few hills. I would like to setup base on the highest elevation on the site but puts me close to the lines about 500’ horizontally. I’ve done some other work along similar type of power lines and was having difficulty with my connection dropping out but of course could have been other factors. Now correlation does not mean causation but just want to know others’ experience around high voltage lines.


(Timd1971) #2

don’t forget your fluorescent tubes.


(Christian Grüner) #3

I like those survey markers :smiley: :wink:
(sorry for off-topic!)


(Hunter) #4

Night GCPs, I like.


(Michael Lambert) #5

The only thing I have experienced is a drop in range. Also, be very careful of ground water and the electric fields.


(Peter Jones) #7

I regularly survey high voltage transmission and distribution power lines.
GPS works fine and you won’t notice any ill effects.
I can’t say about the LoRa radio as I don’t have one but the effects of corona and EMF dissipate rapidly within a few meters of the line.
So as long as your line of sight back to your base is not directly through the conductors you shouldn’t have a problem.
Be careful about using GPS poles under the line, we always use fibreglass non-conducting poles around electricity lines. Stay 5 meters away from the conductors and you should be safe.


(Timd1971) #8

Watch out for falling shows also.


#9

I’ve heard the warnings about using GNSS receivers near high voltage power lines, but I’ve had no trouble around 134kV lines which are smaller and quite low to the ground.

In contrast, the ones in the picture up above with the flourescent tubes must be in the megavolt range.

Also, I think if there is no current flowing or constant current flowing, things might be fine. But, when the current spikes then problems could arise. For example, if a circuit breaker blew or a transfer switch was thrown or there was damage to the lines while you were working.


(Timd1971) #10

You’re probably gonna get a lot of EMI (ElectroMagnetic Interference). So if something isn’t properly shielded from it, you may drop internet connection and/or LoRa radio communication. Probably satellite problems also? May be more of a “nuisance” I would think.

I guess take the safety warnings more so. i.e. standing water, metal objects, unnecessary procreation (don’t think we need any 3-eyed chickens running around), etc.

Let us know how it turns out, hopefully everything will be just fine! ; )


(Hunter) #11

Long day but made it off the site with two legs and two eyes intact. No real noticeable issues, had one point float only out of 13. Good fix majority of day.

Max baseline about 1.5 km. Had difficulty acquiring fix at first so dropped a constellation. Aquired fix and started surveying. Held for most of job until about halfway. Age of differential started spiking, lost my base and went to single/float. Figured Lora was choking on bandwidth so drove back to base and dropped RTK settings to 0.5hz around from 1hz and changed air update rate from 9kb/s to 4kb/s. Allowed me to pick up last few farther points.

Output set at 18 dbm. Frequency 928mhz entire day. Still playing with Lora settings. Will know more about satelites back in office but were ok. In hotel now. Tomorrow is drone day…


(Tatiana Andreeva) #12

Hi @RTK_Hunter,

It’s rather difficult to predict how high voltage transmission lines can affect LoRa connection without tests.
So it’s great to hear your survey went fine!

Would be interesting to see the result.