RS2 fix with a very high age

I still experience fixed points with RS2 at a very high age. In this case it is with Lora and with Ntrip too!

I have sometimes seen this too.


Looks like a jello-fix to me. This is something people are going to have to get use to seeing with the RS2’s. With the RS+'s it was pretty straightforward whether you had a fix or not, but with the RS2 (as we have experienced for years with other multi-channel receivers) you will be fixed or on that line between fix and float so often that you will need to slow yourself down when collecting crucial points. A nice change I would think over pleading with a receiver to speed up. One feature request I would have is to create a definition to establish a difference between collecting a topo shot and a control point. In our software there are two different selections for measuring and each options has it’s own criteria. A topo shot is typically a short burst (5 seconds) while a control shot is much longer, typically at least 45-60 seconds. The RMS tolerances are also separately definable. These types of settings will definitely help with safety as we become complacent on occasions.


In my work I don’t use less than 15 seconds per point, but with a fixed solution I can’t take a risk with 40 years of age. It is necessary when the age exceeds 5 of age and thus allows me to measure a static point and be able to postprocess it in my office and so I will be safe. The problem is when the Lora signal is interfered with by trees, if it is free this does not happen.

Is this because of past experience? As in what worked with the RS+? If so I think you will be surprised and perhaps learn to embrace the full capabilities of the multiple channels. Something like driving in a car at 10mph collecting a point every 5 seconds wasn’t really feasible before…

haha yes !! It depends a lot on the conditions of the place. So should I trust RS2? with RS + I felt very comfortable

My profession is to determine legal property limits, so I need security. With my old Promark 3 rtk there were also uncertain things. With RS + I had better conditions to be able to measure at any time

Even with topcon RTK ntrip the problem of fixed occurs when the connection is lost.
To feel comfortable I must always observe the delay of the rtcm message.

Just to comment on this , I know on the John Deere system you can loose corrections for 30 min before it would loose its fix . They called that RTK extend but the newer recievers now will go something like 2 weeks and be fixed without getting corrections



now that is some serious fix-and-hold!

Yes but that comes with a price $6000for the reciever and another $6k for the subscription

OK, 2-week fix is done. Where do I collect the extra $4k plus $6k per year? :smiley:

Sorry @agrimgalina, for you I will do the opposite for a small fee :stuck_out_tongue:

(Actually, I’m just kidding and don’t know what the effects are of changing that value to such an extreme number.)


Be aware that if the age of fix is longer than a few seconds, it’s not a good fix in any machine or brand. Mathematically fixed integer solution is not the same as an accurate location. You may be able to post-process a very good fixed location later in the office, but if there’s no live communication with the base, that’s no different than turning off the base while you continue to survey.
To get accurate fixes in the field with an extended age, the RTCM3 corrections would have to be passed over BT, TCP, Wi-Fi, etc. (not LoRa) and processed on a decent CPU on the fly. I’m not aware of any equipment that does this.

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You lost me here. When we say ‘extended age’ are we not talking about the fact that the corrections have not been received for n seconds? And if so, then some extra horsepower is needed to run predictive analysis on the aged corrections? Is that what you mean?

Not predictive analysis. Retroactive analysis. The base broadcasts RTCM3 live. So if you miss a gap, you won’t have perfect data unless you could somehow query the RTCM3 log, and do a partial PPK on that portion. The number crunching would need a decent CPU (probably not a mobile CPU). LoRa doesn’t have the bandwidth to do that. You could -in theory- keep the base log synced on both sides and get something between RTK and PPK in the field. Again, I’m not aware of any equipment that does this. Would be a really nice workflow.


Yes then. Property corners are basically the same as control points in my world. Topographic surveys and GIS work are pretty much the same everywhere. Difference with the multipath kits is that you can stakeout a 3-5 sec topo shot within 0.03’ +/- .01’ for every 1000ft.

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OK, I see what you are getting at. You mean where the rover detects any missing RTCM3 data, then requests it later, then goes back and reprocesses any inferior single-solution into fix/float solution and amending either those previously collected points or the previous position log.

That is a neat idea, “self-healing” any problems with your rover data collection as soon as it gets back into communication with the base. I like it.

However, I think what @davehofer1993 meant is that the tractor/equipment GPS unit will hold a fix for up to 30 minutes or even two weeks after loosing corrections. That is a whole different animal I think. For that case you might need a crystal ball to predict the future. I’m not sure how they do it.



I can’t see how that’s at all possible to hold a fix that long. I’d be extremely skeptical and want to verify any measurements. I believe it’s obtaining fixed integer solutions using the last known correction. Mathematically, you can call that a fix. But that’s making assumptions that there’s no variability in the atmosphere. Unless your taking measurements in space, you’re getting bad data.

I am just as surprised, but if they can somehow hold the fix and have it be better than single mode, then it is still better for tractor use. But maybe not what we’re looking for in land survey applications. :wink: