RTK issue

[Clive]

Drilling at the end of last week and the tractor kept dropping signal, Had techs here sorting the issue who spent an entire day swapping hardware about and updating software etc but still had the problem, they left with no idea what was causing it at the time

No problem on other machines working on other parts of the farm much further away on the same day

Over the weekend we took 2 other machines to the same block of land and to test and they both drop signal there, so by a process of elimination we now suspect that something is interfering or blocking the signal in this area.

This isn't new land, the RTK has worked faultlessly there for 3 years so if it is interference its a new device in that area causing it which surely shouldn't be licence if it interferes with existing kit in the area ?

We pay OFCOM a licenece for the RTK, are they supposed to protect our frequency form such problems ? its made steering less than ideal on 300ac with I'm clearly not happy about

 

[B'o'B]

Drilling at the end of last week and the tractor kept dropping signal, Had techs here sorting the issue who spent an entire day swapping hardware about and updating software etc but still had the problem, they left with no idea what was causing it at the time

No problem on other machines working on other parts of the farm much further away on the same day

Over the weekend we took 2 other machines to the same block of land and to test and they both drop signal there, so by a process of elimination we now suspect that something is interfering or blocking the signal in this area.

This isn't new land, the RTK has worked faultlessly there for 3 years so if it is interference its a new device in that area causing it which surely shouldn't be licence if it interferes with existing kit in the area ?

We pay OFCOM a licenece for the RTK, are they supposed to protect our frequency form such problems ? its made steering less than ideal on 300ac with I'm clearly not happy about

Ofcom almost certainly won't know if some is broadcasting illegally until you tell them. I'll be interested to hear what their response is like.

 

[Stoxs]

military?

not sure what is around you but have heard of military radar and frequency blocking equipment knocking out GPS systems. Often ofcom wont even know if it is military.

 

[Northern farmer]

Puzzles me if the question is about GPS visibility or if the correction signal got lost. Is the interference on the GPS frequency or on the frequency of the correction signal radio? Should be easy to figure out from any screen.

 

[Pheasant Surprise]

Radio scanner run at around your UHF centre frequency would be able to show what else was being transmitted. Would need to switch your own transmitter off first.

Edit:
How far away from base is this particular block? Presumably you have some housing etc around this block that may be causing the interference you suspect. Unfortunately UHF2 is a pretty 'dirty' part of the spectrum. Someone could legally be transmitting at the same base frequency at yours (at 1W power or less) without an Ofcom licence. The only way you'd know for sure is to use a scanner or digital UHF radio trained to your frequency. Be interesting to know what Ofcom would bother to do in this situation.

Not an ideal solution, but can you get your hands on a mobile base to get you out of jail? Set to a different base freq. of course.

Can you get decent mobile (data) signal there to get NTRIP? Can your home base run as an NTRIP caster?

I suspect and hope LH Agro are all over it for you though trying to find a solution.

 

[Robt]

We are on it.
Rob
LH Agro

 

[Teejay]

I had this happen to me a couple of years ago, a 40 acre field away from the farm, when I went to spray no signal gps couldn't track satelites. Went back to farm and it worked. I blamed the mobile phone masts each side of the field. There is also an army cadet base near to the field. I have just accepted that the gps won't always work in this field.

 

[Pheasant Surprise]

Any news @Clive on what the issue is/was?

 

[Clive]

Any news @Clive on what the issue is/was?

not totally sorted other than we know it's not the tractor as 4 separate RTK equipped machines / LH van all get the same issue

Its not the RTK radio signal either as we tried network RTK and that drops as well ! plus even when dropped we get a RTK count, its seems whatever is causing the drop blocks all satellites which is very odd as this is top of a big hill, no trees etc

so still a mystery really ! it's all drilled up now so not a problem until we are next there !

 

[Pheasant Surprise]

The big hill, isn't a hill at all Clive its a buried alien mothership

 

[Robt]

Or a teenage mutant turtle doing some. Secret research......

 

[Pheasant Surprise]

 

[Robt]

Knew I recognised you! Seen you outside the kings head on a Friday wearing just that hat!

 

[Pheasant Surprise]

In all seriousness how many times have you come across this type of satellite signal loss / interference in rural areas? Can imagine there could be more issues in dense urban centres but in a rural setting? Is someone likely to be jamming it?

Do you get Ofcom on the case? Can you get access to a spectrum analyser or wideband radio scanner to see what's going on?

Are there any nearby military bases or airfields using some sort of radar (or practicing with their anti enemy GPS jammer). There must be a logical explanation.

 

[Pheasant Surprise]

"The future GNSS signal designs (GPS, Galileo, GLO-NASS) are combating against unintentional and inten-tional interference with, for example, longer codes, dataless pilot signals, and higher transmission powers, and overall, it is much more complicated and expen-sive to jam multiple frequencies at the same time. Systems all over the world have been created to detect jamming/interference.

For example, in Britain, the Senti-nel research project used 20 roadside monitors to detect the use of jammer (Vallance, 2012) and the GAARDIAN project monitors the integrity, reliability, continuity and accuracy of the locally received GPS and eLoran Radio Navigation signals creating an alarm network (GAARD-IAN, 2012)."

The GAARDIAN project is a UK Government funded collaborative R&D project to develop solutions for analysing interference phenomena assiciated with Positioning, Navigation and Timing (PNT) signals, including GPS and eLoran in safety and mission critical applications. The industrial and academic collaboration is led by Chronos Technology Ltd, includes University of Bath, General Lighthouse Authorities, BT, Ordnance Survey, National Physical Laboratory and Imperial College London.

http://www.chronos.co.uk/index.php/en/gaardian

Have you heard of this stuff @Robt ?

 

[Pheasant Surprise]

Or a teenage mutant turtle doing some. Secret research......

Well someone else was "demonstrating" some jamming tech around the end of last month. Wales though...

http://www.gps-world.biz/index.php/...ation-of-a-gps-jammer-triggered-camera-system

Coincidence?

Edit: they've dubbed the jammer detection thing JammerCam. Even gone and trademarked the name.

 

[Fish]

I'm not sure about the military radar thing as much of our land surrounds a RAF/Army base where 2/3 radar dishes are working 24/7, and so far we have never had a problem with RTK or gps dropout.

 

[Pheasant Surprise]

I was being a bit facetious about the military radar, but as you can read from the posts above the jamming (and jamming detection) technology is real.

There could of course be natural conditions and causes for the loss or massive degradation in signal like peculiar atmospheric effects, sunspot activity etc.

 

[Clive]

all working faultlessly over the rest of the farm, working 17 miles away today with no problems

just this one block of land on a hill which is odd !

 

[Pheasant Surprise]

all working faultlessly over the rest of the farm, working 17 miles away today with no problems

just this one block of land on a hill which is odd !

You need to give it a name to remember like 'wavy line field' or 'black alien field'