RTK signal interrupted

[casemx 270]

Can a RTK signal be interrupted at it leaves the base station by such things as wind turbines and make the signal drop out on the receiver ? Thanks

 

[Badshot]

You can get interference to rtk. I've had it from power lines in a neighbouring field

 

[Clive]

Can a RTK signal be interrupted at it leaves the base station by such things as wind turbines and make the signal drop out on the receiver ? Thanks

yes - we had a problem on a block of land last year, after lots of investigation by LH it was put down to signal blocking by a local military receiver, it was fine for 30mins or so but then all machines working close would loose all signal for a minute when interference cut in

 

[Pheasant Surprise]

Can a RTK signal be interrupted at it leaves the base station by such things as wind turbines and make the signal drop out on the receiver ? Thanks

UHF generally is more affected by terrain and foliage (than say VHF), it's penetration (pardon the pun) isn't as good, the signals don't travel as far. If you're a long way from the base, the signal will naturally be weaker, the radio will have a harder time trying to distinguish noise from real information.

A high-power fixed base will have a more robust service than say a low-power portable base running a license-free frequency. The fixed base will be licensed which means it could be as much as 20 to 30 times as strong a signal at the same distance. There's also a lower chance of interference from other users, not impossible, but a lower likelihood - the portable bases only has 15 or so channels in the free spectrum allocation, so it could get congested, from other radio users.

Then there's deliberate interference - but that's fairly rare. Or the oddball stuff that Clive experienced. Tin hat time!!

Satellite signal interference and spoofing is a whole other kettle of fish, but that is very, very rare. For now anyway.

 

[Tractor Boy]

Not on RTK but have had strange phenomenon in that my Trimble centrepoint signal has dropped out when Apache helicopters have been in the close vicinity!

 

[Northern farmer]

Not on RTK but have had strange phenomenon in that my Trimble centrepoint signal has dropped out when Apache helicopters have been in the close vicinity!

But it comes from a low elevation satellite, you don't need that fancy devices to block the signal.

 

[Tractor Boy]

But it comes from a low elevation satellite, you don't need that fancy devices to block the signal.

I know, but we were right out in the open both times. No problem until one of the local Apache's turned up only a few hundred yards away. Signal dropped out and returned when he was out of sight.

 

[casemx 270]

Thanks for replies

 

[casemx 270]

As the crow flies how far from the base station is OK ,there are hills and valleys trees etc

 

[Pheasant Surprise]

As the crow flies how far from the base station is OK ,there are hills and valleys trees etc

On a single baseline (different story for network RTK with VRS blah blah) you're going to get unacceptable accuracy degradation beyond about 40-50km, but it's academic as you'll never get a UHF radio signal to travel that far from base with normal radios, antennas etc.

Again depends on the terrain etc, but a realistic goal would be 20 maybe 25km with a good fixed base setup with line of sight. Mountains, hills, valleys, heavy stands of trees in the way won't help one bit!

The proof is in the actual received signal strength at the radio. They won't work reliably below received signal strength about -110 dBm or so - an external radio tells you the signal strength on the display, otherwise with radio hooked up to a laptop, it's just a simple command.

In a nutshell if you're worried it might not work, get a proper radio survey done.

 

[casemx 270]

It worked great last year but the provider got told to turn the strength of the signal down so now its no where near as good but also 9 wind turbines have been sited close to the base station so was just wondering if that might not help

 

[Pheasant Surprise]

It worked great last year but the provider got told to turn the strength of the signal down so now its no where near as good but also 9 wind turbines have been sited close to the base station so was just wondering if that might not help

Sometimes they're operating within their licence limits, but told to turn things down because of legitimate local reasons - usually something like airports nearby; possible radar or aircraft comms interference etc.

Fixed bases in the UK will typically be operating on a 25 kHz channel, so according to their licence they *could* be pumping out up to 100 watts at the antenna. If the license is area defined, as most fixed bases are, then there are maximum signal limits at the physical boundary of the license - basically along national grid squares.

I don't know who or where you're getting your signal from, but if your signal strength (and service) has gone up the swanny, you could arrange to have a radio repeater installed. Basically it's just another radio like at a base, just programmed to receive and repeat the correction messages. Whether they decide to do and fund it is another matter entirely, but it can be done technically.

 

[casemx 270]

We understand that repeaters arnt any good they have one going in the other direction away from us although I don't know any details but they have had loads of problems with it .

 

[Northern farmer]

How is your cellular coverage? If RTK via radio gets interrupted, you could use NTRIP via GRPS. Easiest if your signal provider offers that option, if not, you could set up a relay.

 

[Pheasant Surprise]

We understand that repeaters arnt any good they have one going in the other direction away from us although I don't know any details but they have had loads of problems with it .

Who's your provider and what radios are you using?